Wave rotor demonstrator engine assessment

Document

NASA Contractor Report 198496

Philip H. Snyder

Allison Engine Company, Inc.

Indianapolis, Indiana

June 1996

Prepared for

Lewis Research Center

Under Contract NAS3-25950

i National Aeronautics and Space Administration I CONTENTS LIST OF TABLES LIST OF FIGURES Figure Figure Figure Figure Figure Figure Figure Figure Figure

LISTOFFIGURES continued Paagg

Figure

DISTRIBUTION LIST

3. Use current materials and technology.

1. SUMMARY 4. Utilize existing engine hardware to a high The wave rotor topped gas turbine has shown degree.

significant promise for engine performance 5. Impose minimal mechanical complexities on enhancement in both previousCI,2) and ongoing the engine.

analytical studies. One of the important next steps for The first of the requirements stated above sets the goal moving this technology toward implementation in a substantially higher than that of assembling an engine commercial application is the demonstration of this able to merely achieve self-sustaining operation or technology in an engine. The assembly of a successful attain levels of performance routinely found in wave rotor demonstrator gas turbine engine is a production engines. In fact, assembling an engine necessary and logical step in the maturing of wave rotor accomplishing these lesser goals would, in itself, be a technology and the assessment of the benefits of its significant step forward in wave rotor engines, but integration into propulsion and power generation insufficient, the author believes, to show the concept's devices. A successful demonstration can greatly true merit. Certainly meeting requirement 1 will enhance the understanding and acceptance of wave necessitate the use of requirement 2. The wave rotor rotor technology. In this way the potential for concept must be employed to the best of its present incorporation of wave rotors into commercial gas potential in order to demonstrate full merit. With turbine engines may be more accurately assessed.

regards to number 3, the focused development of a The objectives of the program were to establish the single new technology both enhances the opportunity of viability of assembly of a demonstrator wave rotor a successful outcome and clarifies the source of any engine using the Allison model 250 turboshaft engine noted engine performance. Requirement 4 allows as a basis. Design point and off design operation of the program funding to be dedicated to the wave rotor engine was assessed. A preliminary design of the components and avoids development effort being engine was performed. Cost and schedule for detailed diverted away from the stated goal. Finally, the design, fabrication and test of the engine were opportunity for success of any program is enhanced estimated.

where simplicity can be maintained. In addition, credibility as to future product potential is boosted as Results of the program show how a successful wave simplicity in implementation is demonstrated.

rotor topped demonstrator engine may be assembled using existing hardware. The engine has the potential As a basis for the effort, the Allison 250 (military of demonstrating excellent design and off design classification T63) turboshaft engine series was performance. The wave rotor demonstrator engine has selected as a candidate for use in the demonstrator. A a predicted 733 hp power output at design point, a typical 250 engine is depicted in Figure 1. Basis for 11.4% increase relative to the production version this selection is derived from its low cost, low corrected baseline engine. SFC improves substantially also with flow, relatively low cycle pressure ratio, engine layout, a 22% decrease relative to the baseline. The design of and the numerous models of varying design point air the burner represents the greatest challenges due to high flow from which to select components. Table I burner inlet temperatures.

summarizes relevant data for this engine line. Previous studies had identified major gains available to engines of low cycle pressure ratio with application of the wave 2. INTRODUCTION rotor concept.

2.1 Program Structure.

This program is designed to be part of a larger study at NASA LeRC, both analytical and experimental, The work reported here was accomplished in 6 developing the four port wave rotor concepts in a multi- subtasks. Under subtask A, a viability assessment phase program. Planned additional phases target the evaluated the probable success of formulating a suitable experimental evaluation of a rotor capable of being wave rotor demonstrator engine utilizing the Allison installed in a demonstrator engine. The program 250 engine. There are several wave rotor cycles that reported here performs the engine analysis need to may be suited to a turbine engine application.

identify existing engine hardware capable of being Candidate wave rotor topping cycles were considered assembled into a successful demonstrator engine and a screening process used to indicate a preferred program.

cycle. An engine cycle study performed indicated that from a performance and flow capacity standpoint, A potentially successful demonstrator engine program improved engine performance could be realized. A is perceived as one which can: 1. Demonstrate a meaningful degree of improved preliminary selection of basic engine components allowed the key design parameters of the wave rotor to engine performance.

be established. Using this data, candidate wave rotor 2. Aggressively incorporate wave rotor technology. design point flow size, pressures and temperatures were established. NASAthendesigned thewave rotorand * Whereas the flow within a rotor passage is prepared mapsof its performance. Rotorinletarea, unsteady, the flows entering and exiting the rotorsize(diameter, length) androtational speed were rotor through the ports are steady with some established.

amount of pulsating component.

• The rotor turns to provide opening and closing

Subtask B performed a design pointstudyusinga

of the passage end points, not to provide

detailed cycleanalysis employing these waverotor

change in angular momentum of the entering

maps.Determined in thestudywerefinalvalues of

and exiting flow streams.

waverotorflow,inletarea, androtorrotational speed.

• The wave speeds are sonic or greater but the

Engine design point temperatures, pressures, and burner

gas speeds are everywhere subsonic.

design conditions weregenerated. A range of engine

• The device is not a partial admission turbine

hardware suitable for usein thedemonstrator engine

was considered witha final selection based on minimal and compressor combination.

alterations to production engine hardware. A criterion Figure 3 illustrates how a wave rotor device may be carefully adhered to in the design was the replication of used to top a gas turbine engine cycle. A properly the production engine's compressor surge margin.

designed wave rotor can act as a high technology Subtask C extended the design point cycle work to an topping spool to a gas turbine engine. It increases the effective pressure ratio of the engine as well as off design point analysis. The cycle study determined increases the effective turbine inlet temperature. In part power performance including idle.

contrast to a conventionally configured topping spool, Under subtask D, a preliminary engine design resulted the wave rotor offers the following advantages: in an engine layout. A list of engine hardware to be modified and new hardware to be procured was • Mechanically simple.

assembled. Also addressed was the. effect of wave • Low rotational speed.

rotor output pressure pulse on turbine design.

• One unit accomplishes both compression and turbine functions.

In subtask E an estimate of engine build and test cost • Self Cooled.

was made. A schedule for accomplishing same was also established.

• Conducive to application at low corrected flows.

Subtask F included the reporting effort.

The self cooled feature of the rotor is derived by the 2.2 The Wave Rotor Concept exposure of the rotor walls to alternatively hot then cold flow in rapid succession, thus bringing the wall to an The wave rotor concept is based upon the use of average temperature which is well below the peak cycle transient fluid dynamic processes occurring within flow temperature. Fluctuations in wall temperature are passages mounted on the circumference of a rotating modulated by the thermal inertia of the wall.

drum as depicted in Figure 2. In general, the term wave rotor does not define a specific device but rather a Design of a wave rotor to successfully augment a gas broad classification of devices. In this particular turbine engine is not a straight forward process.

application, pressure and expansion waves together Basically, the design of a wave rotor enhanced engine with direct hot-to-cold gas flows are made to perform starts with the design of the cycle of wave processes on functions commonly reserved for steady state processes board the rotor. The cycle design is accomplished in conventional gas turbine equipment. The transient through innovation using an understanding of the processes are made compatible with steady flow transient flow processes. A successful design utilizes devices (compressor and turbine), ahead of and behind the transient processes to the best advantage of the gas the device by making the transient processes cyclic turbine within the limits of inherently imposed within the passage and utilizing a series of tubes with constraints.

staggered phases of the transient process occurring in adjacent passages.

In considering the wave rotor and its unique transient 3. RESULTS AND DISCUSSION based operation, the gas turbine specialist may have to 3.1 Subtask A - VIABILITY ASSESSMENT.

overcome a number of potential pitfalls in thought hindering his understanding. The following list is The gas processes occurring within the wave rotor are intended to address common misconceptions: depicted in Figure 4, the wave diagram of the through- • The pressure waves in the rotor passages are flow (TF) wave rotor cycle. This particular cycle is not standing waves but instead travel the explained in detail in reference 2, where it is explained length of the tube.

along with the other competing candidate, the reverse-

dictates thatthecompressor operate atornear itsdesign

flow (RF)cycle.Thediagram describes theprocesses

in therotorby tracing the"trajectories" of thewaves flowand pressure ratio,generally near therated power

pointofthebaseline engine. Similarly therequirement

andgasinterfaces within the rotor. Shockwaves

to maintaincompressor surge margin in the

trajectories areshown hereasbroad solidlines,and

demonstrator engine at baseline levelsconstrains the

expansion waves (actually fans)areshown aslight

design operating pointtonear baseline engine levels.

dashed lines.Hot-to-cold gasinterfaces areshown as

heavier dashed lines. Individual passages andwave

Withthecompressor operating near itsdesign pressure

frontsarenotgenerally shown in thediagram aswas

ratioandflowandtheturbine operating atits design

donein Figure3 for instructive purposes. In many

inlettemperature, thepressure attheturbine inletin the

ways anunderstanding ofa wave diagram is asbasic to

demonstrator engine will of necessity be higher than

theunderstanding of a wave rotor astheunderstanding

thatof thebaseline engine.Theendresultis thata

of a velocitydiagram is to thatof a conventional

changein the turbine hardware is requiredto

turbine orcompressor.

accommodate thereduced turbine inletcorrected flow

due to the higher turbine inlet pressure, while

Numerical methods validated by experimental results

arenowavailable to perform thedetermination of the maintaining appropriate efficiency andworkextraction wave processes occurring onboard thewave rotor. 3,4,5 in theturbine section. An apparent conflictthusarise

between theuseof existing engine hardware andthe

Wave diagrams produced bysuchmethods areshown

need toreduce theturbine section flowcapacity.

in Figure 5 andarepresented in terms ofcontour plots

of pressure, density andvelocity.Pressure plotsshow

Considering the250model line in particular, theneed

shock andexpansion waves andthedensity plotvery

tomodify turbine flowcapacity may beaccommodated

clearly showsthe placement of hot-to-cold gas

by a "mixandmatch" strategy combining compressor

interfaces.

andturbine section fromtwo of the multiplicityof

Twobasic wave rotorcycle designs were considered in differentenginemodels available.Engines in this thestudy, these havingbeen selected froma broader product linerange in mass flowatdesign pointfrom3 to7 lbm/sec.

groupof candidate cyclesstudied in previous work.

Thetwocycles aretermed thefour-port through-flow

Thecycleanalysis carried out in this phase of the

(TF)andfour-port reverse-flow (RF)cycles.Each is

program identified a favorable engine selection using

identical in its overallperformance but they differ

thecompressor ofthe250 C30engine together withthe

substantially in theirinternal layout.A comparison of

turbine section of the 250C28Cengine.With the

thepositive and negative characteristics ofeach cycle is

turbine inlettemperature (TIT)maintained at1930 F in

detailed later in thissection. Due totheidentical nature

thetopped engine, atopping cyclepressure ratioof 3.0

of theperformance of thetwocandidates, theviability

wasachieved through addition of thewave rotor.The

study could becarried outwithout regard tocycle type.

pressure of thegasentering theturbine wasincreased

Overall performance characteristics used intheviability

by a factoror 1.2asa result.Performance improve-

studyweretaken fromreference 1 andareshown in

mentsweredramatic with an increase of 20%in

Figure 6.

specific shaft horsepower (SP) and decreases inspecific

fuel consumption (SFC)of 22%indicated. Improve-

Toappropriately guide theapplication ofa wave rotor

ments ofthismagnitude together withfavorable results

to anexisting engine theinherent characteristics ofthe

regarding component selectionessentially proved

wave rotor cycle must dictateseveralimportant

concept viability.

decisions. In general engine SFCimprovements are

realized through cyclepressure ratioincreases. The

Asdescribed above, analysis conducted tothispointis

wave rotortopping cycleachieves thisin anexpedient

equallyapplicable to boththe TF and RF cycles.

manner andthe maximum levelsof topping cycle

Subsequent tasks objectives,however,required

pressure gainarerealized by attaining a maximum

selection of a particular cycle.Wave diagrams of the

temperature ratioacross thedevice asshown in Figure

two cycles sideby sidein Figure 7. TheTF andRF

6. These characteristics show thatasT4/T1 increases,

cycles differin direction of flow into andout of the

P4/P1 increases. Theoverall pressure riseacross the

wave rotor.TheTF routes allgasses through therotor

topping cycleisthus setbytheratioofthe turbine inlet

lefttoright.TheRFbrings coldgas intoand outofthe

temperature to thecompressor discharge temperature.

same sideoftherotor.Thisis alsotrueof thehotgas

Thepursuitof maximum performance improvement

flow. Thus theRFcycle does notinherently have a self

thus results inanengine cycle fullyutilizing theturbine

cooled rotor. In orderto achieve a self cooled RF

inlettemperature capabilities ofthebaseline engine.

design, a two cycleperrevolution design of theRF

configuration mustbe constructed whichorients the

In retrofitting a wave rotorintoanengine design, it is

cycle alternately rightand leftontherotor asillustrated

mostimportant to avoid compromising thecomponent

in Figure 8. A number of thepositive andnegative

performance by pooroperating pointselection. This

characteristics of each cycle are presented in Table II. Scaling of the turbine hardware over a limited range is The "IT cycle appeared to be a more advantageous applicable when utilizing existing hardware. The employment of modification techniques commonly selection for purposes of a demonstrator engine.

Essentially, demonstration of self cooled rotor used in engine development programs, but feasible for capability, with a mechanically simple arrangement, use on production engine parts makes this possible.

was judged highly desirable. The result of the selection These modifications leave turbine efficiency essentially unchanged while altering flow capacity over a narrow process, due to its limited scope and narrowly defined objective, is not intended to be a definitive indicator of range.

absolute merit of either candidate in the topping of gas The use of compressor bleed to control surge margin turbine engines in general. Selection in individual was ruled out because of its severe impact on engine applications will require careful examination of all performance. Although the influence of the bleed flow competing concepts.

could be accounted for and the engine performance 3.2 Subtask B, DESIGN POINT ANALYSIS analytically compensated to remove this penalty, this approach was rejected in favor of a more defensible Prediction of the performance of the wave rotor was demonstration of performance improvement.

accomplished through the use of a detailed map of the Results of the study indicated that the selection of a 250 wave rotor cycle performance generated over a broad range of operating parameters. Design of the rotor and model C30 compressor joined to a C28C turbine section downstream of the wave rotor, resulted in a preparation of the performance maps used in this study demonstrator engine having the greatest performance are the accomplishment of Jack Wilson and Dan Paxson of NYMA, Inc. and NASA Lewis Research Center increases possible using existing hardware. Flow respectively and were based on their work 1,2,4. Effects capacity of the turbine hardware was increased by 1.4% for both the gasifier and power turbine. The flow of fluid friction, heat transfer, and leakage are included capacity of the basis wave rotor design was increased in this analysis. One representation of the resulting by 6%. The revised dimensions are identified in Table map is shown in Figure 9 and 10. Mass flow and heat III for the wave rotor design as matched for use in the addition are represented in terms of dimensionless demonstrator engine.

corrected parameters in these maps but were generated for a specific set of design variables as defined below: The baseline engine becomes the 250 C30 engine producing a nominal 650 shaft horsepower at maximum continuous rating with an SFC of 0.59. The demonstrator engine has a predicted 733 shaft

Q

COIT horsepower with an SFC of 0.45. Comparative design point results are quoted with both engines operating at a turbine inlet temperature Of 1930 F. Application of _he and wave rotor thus yields a 11.4% increase in shaft horsepower, a 20.0% increase in SP, and a 22% decrease in SFC. These improvements are very ml RTI/// impressive and show the potential for a very successful mc°'T = / gc demonstrator engine test.

A summary of the wave rotor design is shown in Table Design point operating conditions within the III and details of the wave rotor design and its demonstrator engine are detailed in Figure 11.

performance are documented in Appendix A.

Comparing station 4 with station 1 shows a 1.24 pressure gain across the wave rotor section. The burner A detailed cycle analysis was used to model engine inlet operates at a pressure ratio of 3.37 higher than the operation. Maps of compressor, gasifier and power compressor discharge. Turbine inlet temperature is turbines, and wave rotor performance were utilized for held to the production engine levels (1930 F) while a number of component selection sceneries. The study burner exit temperature is at the 2605 F level. Gas was constrained by the following: expansion within the wave rotor thus realizes a 675 • retain production engine compressor surge degree reduction in gas temperature before the turbine margin.

inlet station is reached.

• scale turbine flow capacity less than 5%.

Note that the burner inlet temperature is elevated • avoid the use of compressor bleed to achieve significantly above that expected for a conventional surge margin.

cycle. This is due to an inherent feature of the TF wave • scale the wave rotor flow capacity less than rotor cycle which recirculates through the burner loop a 10%.

mass flow 60% larger than that entering the wave rotor

matching resulting in gasifier shaftspeeds averaging

fromthecompressor. Thisimpacts theburner design

significantly, aswill bediscussed in section 3.4. 6%below design.

3.3Subtask C. OFFDESIGN OPERATION. Figure15examines thepressure gaincontribution of

thewave rotorin analternate way.Thepressure gain

Thecyclemodel of theengine wasexercised overa 6

fromcompressor discharge to turbine inletrepresents,

pointsetofpower settings ranging fromidletotake off

in a simplified way,thecontribution of thewave rotor

power.Figure 12compares SPand SFC forthetopped

to thecycle.Thisratioapproaches 1.24at thehigh

andbaseline engines asapercent improvement forthe

power settings and lowers to 1.09 attheidleconditions.

off design points.Bothcomparisons show exceptional

A second wayof examining theoverall contribution of

performance improvements bythedemonstrator engine

thewave rotor istocompare burner exittemperatures to

withincreasing gains aspower output is reduced. Idle

turbine inlettemperatures across therange of power

performance wasimproved witha 19% increase in SP

settings. Figure 16indicated that thedifference in these

and a 32% decrease in SFC. For eachpoint,

temperatures remains nearly aconstant 600 degree level

compressor surge margin was maintained atproduction

withsome additional gainshown atthehighest power

engine levels.Withrespect to compressor operation, setting.

oneconsequence of usingexisting components was

noted in thespeed of thegasgenerator. Thedesign

Gaspathtemperatures throughout thecycleareshown

speed match pointof thetopped engine is 6%below

in Figure17. It canbe notedthatat equalshaft

that of the production engine.This resultsin a

horsepower pointsfor the two engines, production

somewhat oversized compressor andturbine system

engine rotorinlettemperatures are60 to 75 degrees

compared totheproduction engine.

higher than those in thewave rotor topped engine.

A closer examination oftheworkings ofthewave rotor

Onedisadvantage of thetopped engine relative tothe

is shown in Figure 13withtheengine operating points

production engine is clearly noted when examining the

placed onthewave rotoroperating map.Design point

burner inlettemperature concern mentioned earlier, this

operation fallsnear theknee of thecurve atthedesign

timeacross therange of powersettings. Figure18

heataddition level.Aspower output is decreased, the

indicates thatdueto the combined effectof higher

operating pointmoves toacurve of lower level of heat

compression ratioandhotgasrecirculation, theburner

addition. Theoperating point remains near theknee of

inlettemperatures operate from600to 1000 degrees

the curve in eachcase. This characteristic is

higher forthedemonstrator engine when compared to

maintained overtheoperating range including theidle

the baseline engine.This moves the designof the

points.It canbe noted thata number of idle points

burner toa significantly higher leveloftechnology than

were runoverarange ofpower turbine speeds toassess

that existing in the baseline engine today.

sensitivity. Engine operation wasacceptable at each

point examined.

As described above,wave rotor speedis self

determining dueto thefree wheeling design selected

Also shown in Figure13is theP5/P1 pressure ratio

foruse in thisstudy. A comparison ofthespeeds ofthe

characteristics of thewave rotorandtheplacement of

wave rotor and gasifier shaft inthedemonstrator engine

the operating points onthismap.It is noted thatthe

is shown in Figure19. The waverotor speed is

operating points fallupon alocus ofpoints representing

approximately a constant 1/3of thegasifier speed for

a maximum in P5/PIas corrected heataddition is

all power points, withtheratioapproaching 1/4atthe

altered. P5represents theburner inletpressure, which

idle powersetting.Thefeature that at power,the

appears to be maximized in this operating point

rotational speed of the waverotor remains a near

selection.

constant fraction ofthegasgenerator speed indicates a

favorable result if some typeof mechanical lashing of

Further examination ofthepressures within theengine

thegasgenerator andwave rotorshafts should become

cycles areprovided in Figure14. Mostnotable is a

necessary as theconcept is examined andtested in

comparison oftheoverall pressure ratios ofthetopped

further work.

andun-topped engines. At design pointoperation, the

topped engineapproaches a pressure ratioof 23:1.

Thewave rotordesign upon whichthese performance

Baseline engine levels arenear 9:1.Over theoperating

characteristics were based is outlined in Figures 20,21

range, thewave rotorcontributes a nearly constant 3:1

and22. The wave rotoremploys a2 wave rotorcycles

compression. It shouldbe noted that in the

perrevolution design in orderto accomplish a more

demonstrator engine, theshaft compressor operates ata

advantageous design package Therationale for this

lower pressure ratio than that of the identical

will bediscussed inthefollowing section.

compressor in thebaseline engine. Thisis dueto the

above mentionedless than optimal component

3.4 Subtask D. PRELIMINARY DESIGN

frequency was calculated to be between 10,000 and 13,900 Hz for operation between idle and design point.

The preliminary design engine layout addressed the A first stage turbine blade fast bending mode was following issues: found to exist at 12,500 Hz. It was recommended that 1. Mechanical aspects of component re-match.

the frequency of excitation be moved lower to a 2. Component configuration selection.

maximum of 11,000 Hz. Latitude in selection of wave 3. Wave rotor port ducting design.

rotor passage number indicates that it may be 4. Combustor design.

accomplished without significant performance impact.

5. Wave rotor and adaptive engine parts required.

3.4.2 Demonstrator Engine Configuration Study.

3.4.1 Mechanical Components A highly important consideration in design of the Figures 23 and 24 show cutaway schematics of the demonstrator engine is the proposed layout of the Allison 250-C30 and C28C engines respectively. As baseline engine. The wave rotor section is to be can be readily noted, these engines share a high degree introduced in the flow path at the point normally held of commonality. In addressing mechanical hardware by the combustor. Downstream of the wave rotor, the aspects, the key issues were: conventional flow path picks up again at the turbine • Shaft thrust bearing implications.

inlet. The burner in the wave rotor concept is • Supply of cooling air for the gasifier turbine. connected to the wave rotor both at the inlet and the exit. Due to the additional length occupied by the wave • Compatibility of the gearboxes.

rotor, the ability to stretch the length of the portion of • Potential for forced turbine vibration.

the flow path in the baseline engine between the The layout of the 250 engine minimizes the impact of compressor discharge and the turbine inlet may be increased thrust on component bearing due to a basic highly desirable.

feature of the engine; compressor, and individual Several unique aspects of the 250 engine series are turbine thrusts are carried on separate bearings. This relevant to the selection of this engine for wave rotor implies that a boost in turbine inlet pressure yields a topping. The turbine inlet is directly accessible without simple increase in thrust with no change in thrust required engine gas generator or power turbine shafting direction or large load increase at a low design thrust changes. The dual transfer tube feature at the exit of bearing system such as is common in other engine the compressor is also useful in coupling the engine configurations.

with a two cycle per revolution wave rotor layout.

Cooling air for the gasifier turbine is supplied at An early engine layout concept is shown in Figure 26.

approximately 4.5% above turbine inlet pressure. Mass The layout accomplished direct transfer of the gas flow flow required is 2.2% of the compressor discharge flow.

from the wave rotor to the turbine and used the two Cooling air at the design point is 665 F. A diagram of transfer tubes from the compressor to feed the wave the turbine air cooling scheme is shown in Figure 25.

rotor. However, with the burner placed along side and This air performs a number of tasks and the temperature below the wave rotor, the ducting to the wave rotor level at which it normally arrives plays a key function.

from the combustor is long, hot, and complex in shape.

Although the burner inlet air pressure far exceeds the Shortening of this duct lead to the final engine layout required pressure, so does it's temperature at 1767 F concept as shown in Figure 27. In addition, the engine (+1102 F). For this particular wave cycle, an alternate components are placed on a common center line source of air must be created. Some additional cooling allowing the engine case to be fully utilized in the air may also be required to cool the ducting to and from structure of the engine back through the combustor the wave rotor. It is likely that cooling air can be made module.

available at the wave rotor cycle level. However, the generation of an alternate source of cooling air was not 3.4.3 Wave Rotor Port Ducting.

investigated as such was outside the scope of this effort.

Design of the wave rotor ducting is critical to the With respect to gearbox compatibility of the C30 and successful application of the wave rotor concept. Using C28C models it has been found that the two are the results of the previous subtasks, an engine layout compatible. Interconnecting shafting is common was carried to the preliminary design level by using the between the models and a direct bolt up of components following port ducting design study analysis.

is anticipated.

The engine ducting must conform to the allowable The potential for gas pressure pulses emanating from losses of their individual gas flows. The cycle analysis the wave rotor port 4 flow, entering the gasifier turbine of subtasks B and C assumed: and exciting critical vibration modes in the turbine 1. Compressor to wave rotor losses are hardware was examined. The wave rotor gas pulse unchanged from the production engine.

diffusion followed by acceleration is avoided. This

2. Burner to wave rotorlosses aredetermined by

change mandates changes to the existing engine thewave rotor internal cycle matching.

3. Wave rotortoturbine losses areassumed tobe hardware including the rear turbine bearing support

3.25%. (RTBS). Careful design is required to reduce the

4. Wave rotortoburner losses aredetermined by duct length experiencing high velocity flow. The preliminary design includes a turning vane to thewave rotorinternal cycle matching.

properly guide the flow. The throat is set at the

Totalof losses in 2 and4 above is 8.9%so as to

trailing edge of the turning vane. Figure 31 and 32 achieve wave rotorcycle matching.

present the preliminary design. Proper design of this section requires CFD analysis to minimize

The resultsof the cycle work now allow the

both heat transfer area and flow losses while

reexamination of these assumptions. Design strategy

assuring proper flow into the blade row.

foreach duct hasbeen broken down intoa statement of

thechallenge, followed byapreferred approach tomeet

4. Port 5: Wave rotor to burner:

thatchallenge. In eachcase, theapproach hasbeen

Challenges:

judgedto becapable of meeting thelevelsinitially

assumed appropriate.

a. Receive flow from the wave rotor at 0.33 Mach number, turn 152 degrees and diffuse to 0.15 1. Port1:Compressor towave rotor.

Mach number. Pressure loss requirement set

Challenge: Createa low loss transition from

by wave rotor matching. Total loss from wave

transfer tubeat0.15Machnumber to a valueof

rotor exit at 5 to inlet at 2 is 8.9%.

0.41Mach number in theport,thenexecute a 153

The loss breakdown is: degree turn.

• burner liner, 4.9%, the production engine liner level.

Approach: Accelerate theflowslightly in theturn

• burner to wave rotor, 1.0% estimated

thenrapidlyaccelerate theflow in a converging

based on above port 2 design.

ductto theport. Thisis a straight forward duct

design withacceleration helping tokeep thelosses • wave rotor to burner, 3.0% goal.

low in theturn. Preliminary design is shown in

b. A strong temperature gradient exists across the Figure 28.

flow in this duct, 3100R to 1690R, with a 2. Port 2:Burner towave rotor: 2227R average.

Challenge: With flow from combustor at low

Approach: Turn the flow at port Mach number

velocity, using a short duct, accelerate theflowto

(0.33) and diffuse to 0.15 Mach number in straight

0.35Mach number intotheportwhileturning the

duct. Use high temperature materials in duct until flow23degrees.

temperature mixing is attained. Turning will aid mixing of the hot and cold flows. Figure 33 shows

Approach: Usingexisting combustor transition to

the resulting duct design.

formanannulus, divide theannulus intotwoducts,

then accelerate theflowinaconvergent duct witha

The resulting engine wave rotor module is

simultaneous turn.Figures 29,and 30illustrate the

illustrated in Figures 34 and 35 showing the side design.

and end views. High radius air bearings are selected for the wave rotor handling both radial and 3. Port 4:Wave rotortoturbine: axial loads. The high radius feature lightens the device and its high temperature capability enhances Challenge: Create acompact design withlowloss.

its applicability. Figure 35 clearly shows the dual

Theproduction engine turbine inletgeometry is

nature of the compressor to wave rotor inlet and

designed forverylowaxial velocity intothenozzle

burner inlet external ducting.

row, hence the ducting plusnozzle row hasa

pressure lossmuchlessthanthe 3.35%goal

3.4.4 Combustor Design

targeted here.Wave rotor turbine flow exitsat

0.49 Machnumber.Warning:a designwith

Analysis indicates that a burner design based on a

diffusion followed by acceleration will resultin

modified production 250 R20 burner (Figure 36) will very highlosses exceeding the3.25% goal and thus result in a combustor of superior design. However, the must beavoided.

predicted liner wall temperature is 2500F for a film cooled production design since the burner inlet

Approach: By eliminating the 1ststage turbine

temperature is 1767 F. The standard liner material,

nozzle row andutilizinga transition ductfrom

AMS 5521, is unacceptable since 2500F is above this waverotor to turn the flow into the turbine, material's limits. In fact this temperature is impractical

for any liner material except ceramic. For a A7. Spacer- turbine containment ring

demonstrator engine, a ceramic liner is deemed too A8. Turbine nozzle mounting flange and support A9. Engine mount expensive and has an excessively long lead time for A10. Misc. parts in gasifier turbine sump procurement.

Alternately, the predicted liner wall temperature is Wave Rotor Components required: 1915F for a Lamilioy liner design. The preferred 1. Rotor material for this temperature range is HA188 with a 3 2.

Forward end plate ply Lamilloy. It is anticipated that peak temperatures 3.

Rear end plate can be reduced an additional 20 degrees with 4.

Air bearing journal shaft optimization of the liner. Such a liner is predicted to 5.

Outer wave rotor assembly case have a life suitable for demonstrator test series.

6. Inner case tube 7.

Air bearing components Thus analysis indicates that through the use of a 8.

Transition ducts - compressor to port 1 effusion cooled liner and a careful selection of non 9. Transition case - combustor to wave rotor exotic burner liner materials, a demonstrator engine 10.

Combustor center body burner may be developed based on a production 250 11.

Support for combustor center body burner.

12.

Duct from combustor outlet annulus to port 3.4.5 Alternate Port 5 Design: Reduction of Burner Inlet Temperature. 13. Duct from port 5 to combustor case inlet 14. Intermediate flange - liner support at The burner inlet temperature may be reduced in the combustor flange through-flow cycle by splitting of the port 5 flow into 2 gas streams. As shown in Figure 4, flow exiting port 5 is composed of a hot and cold streams which mix 3.5 Subtask E Demonstrator Engine Design, Fabrication and Test Cost and Schedule Estimates.

together downstream of the port. Initial gas is hot gas not exhausted to the turbine, followed by gas previously Estimates of costs include: arriving from the compressor and compressed within • Component Design/Analysis the wave rotor. Figure 37 quantifies the temperature • Pattern procurement levels of the two gas streams. (Note that the predictions shown are those for the subtask A viability study design • Fabrication and/or casting point with the average value deviating slightly from the • Machining subtask B predictions.) Hot gases at 3100 R are directed directly to the wave rotor port 2 entrance Costs presented in Table IV are based on fabrication of (burner exit)since temperature levels there are near 3 sets of hardware to be used in the testing phase.

identical. Cold gas at 1600R is routed to the burner Rapid prototype parts are assumed based on computer inlet, lowering the burner inlet temperature from 1767F aided design.

to I140F. This allows conventional materials to be used in the combustion liner and reduces gas mass flow Schedule estimate for this effort is presented in Figure rate to the burner, allowing a significant burner size 39.

reduction.

Figure 38 presents a design concept for the split port 5 4. CONCLUSIONS ducting. The use of internal ducting for the hot gas reduces heat loss and isolates hot ducting from the As substantiated by the viability study results, the exterior of the engine. A feasibility analysis has design point analysis predicts that the wave rotor indicted that the gas streams have appropriate levels of topped 250 engine produces 11.4% more shaft total pressure to allow the required ducting design.

horsepower (+20% specific power) with a 22% 3.4.6 List of Engine Hardware Required For the decrease in engine SFC at a 100% power setting (1930 Demonstrator Engine.

F turbine inlet temperature). The re-match of components can be accomplished using existing engine Adaptive engine parts required: hardware with a minimum of changes. At off design A1. Gasifier turbine rear bearing support operation, the improvements in SP and SFC are A2. Nozzle assembly- gasifier turbine 1st stage similarly improved at part power and idle. Surge A3. Shield - gasifier turbine bearing sump margin of the topped engine is equivalent to that of the A4. Combustor case production engine. The wave rotor delivers a near A5. Combustor liner constant 3:1 cycle pressure ratio boost realizing a 1.24 A6. Misc. exterior pipes and wiring overall wave rotor system pressure rise. Burner inlet • Current material limits pushed in combustor liner

pressure runsat3.3to 3.2X thecompressor discharge

pressure for thepower points.Burner sizeremains at and port 2 transfer duct. Air bearings are selected for wave rotor. Rotor is of conventional materials.

current leveldueto the60%gasrecirculation andthe

600 degree higher burner outlet temperature.

• Score: C

For the components selected, the turbine inlet

4. Utilize existing engine hardware to a high degree.

temperature of thetopped engine runs between 59and

• All existing hardware used except combustor and

74 degrees belowthatof the production engine for

1st nozzle row.

equal power output. Thewave rotoris freewheeling

• Score: A

andspinsat 1/3theNg + or - 3%(15369 atdesign

point).Theburner pressure lossis between 8.8% and

5. Impose minimal mechanical complexities on the

7.9%for thepower points withcorrected burner inlet

engine.

flow goingfrom0.95to0.90respectively. Ngforthe

• External transfer tubes used for ducting to

topped engine is 94%thatof theproduction engine

combustor.

resulting in reduced flow andpressure ratioon the

• Score: B compressor.

Summarizing, a successful wave rotor topped

Thepreliminary design hasverified thatre-match of

demonstrator engine may be assembled using existing

engine components canbeaccommodated withexisting

hardware. The engine has the potential of showing

engine hardware. A stacked component configuration

excellent design and off design performance. The

workswell withtwo cycleperrevolution waverotor

design of the burner represents the greatest challenges

and the250engine layout.The allowable ductpressure

due to high burner inlet temperatures.

losses andgoal pressure losses appear achievable.

Difficultiesfor furthereffort includeidentifying a

source for turbine coolingair supplyandthe high

5. REFERENCES

burner inlettemperatures. Hightemperatures resultin

heatlossconcerns for the two external ductsplus

1. Wilson, J. and Paxson, D. E. "Jet Engine

material selection concerns. In addition, burner liner

Performance Enhancement Through Use of a

material selection andliner design aremademore

Wave-Rotor Topping Cycle", NASA TM 4486,

difficult.A simple change in rotor passage number will

October 1993.

eliminate thewave rotorpulsations coinciding withthe

1 stbend mode oftheturbine blades. A careful study is

2. Wilson, J. and Paxson, D. E. "Optimization of

required tooptimize thetransition ducttotheturbine to

Wave Rotors for Use As Gas Turbine Engine

achieve near conventional engine nozzle row

Topping Cycles", SAlE paper 951411, May 1995.

performance.

3. Paxson, D. E., "A General Numerical Model for

It is instructiveto evaluate the statusof the

Wave Rotor Analysis", NASA TM 105740, July demonstrator engine design relative to thecriteria for 1992.

success established at thestartof theprogram. The

4. Paxson, D. E. and Wilson, J., "An Improved

degree towhich each was metmay beevaluated using a

Numerical Model for Wave Rotor Design and score card approach: Analysis", AJAA 93-0482, January 1993.

A SUCCESSFUL WAVE ROTOR DEMONSTRA-

5. Paxson, D. E., "Comparison Between Numerically TOR ENGINE PROGRAM WILL: Modeled and Experimentally Measured Wave-

1. Demonstrate a meaningful degreeof engine

Rotor Loss Mechanisms", Journal of Propulsion performance improvement.

and Power, Vol. 11, No. 5, September-October • 11.4% SHAFT HORSEPOWER increase, 22% 1995, p. 908, 914.

SFC improvement, even more at part power.

• Score: A+ 2. Aggressively incorporate wave rotor technology.

• The best cycle available was utilized. The potential exists for improvement by using the split port 5 or other yet undetermined cycle changes.

• Score: A 3. Utilize current materials and mechanical technology.

6. NOMENCLATURE units, if symbol definition applicable Q heat addition rate. dimensionless COlT dimensionless moo _ mass flow rate A port flow area P total pressure T total temperature R gas constant x distance in rotor passage L length of rotor passage SFC specific fuel consumption lbm/hp/hr SP specific power hp sec/lbm N mechanical shaft speed rpm Subscripts 1 port 1 conditions 2 port 2 conditions 3 port 3 conditions 4 port 4 conditions corr or c corrected dimensionless design or d design conditions gg gas generator WR wave rotor TableI. PartialAllison EngineCompanyModel 250ProductLine Data.

Take OffPower SFC

Model Weight Pressure ratio

Series I

T63-A-5 C18 141 6.2 317 0.697

Series II

400 0.630

T63-A-700C20 158 7.2

C20B 158 7.2 420 0.650

SerieslII

C28B 228 8.6 500 0.606

500 0.590

C28C 222 8.6

SeriesIV

C30 240 8.6 650 0.592

Table II.

Wave Rotor Cycle Selection Study Results.

Positives Cycle Negatives Type TF Combustor inlet temperature is 600+ degrees Inherently self cooled design. Walls see hot/cold flow at 530 Hz.

higher than RF cycle.

Pressure in combustor is 1% higher than RF cycle.

Pressure loss of 6.5% in combustor loop requires carefully designed ducting.

Mass flow in combustor loop is 60% higher than RF cycle requiring larger ducting and combustor.

RF 1250+F temperature difference from end to end of Simple compact combustor loop due to ample rotor.

pressure drop allowable.

single cycle Average temperature of hot end at 2140F, 310F higher than TF cycle.

Rotor inlet and exit ducting at opposing angles on the same end of rotor complicating mechanical ar- rangement.

RF two Rotor inlet and exit ducting at opposing angles on Average rotor temperature is 200 F lower than the same end of rotor complicating mechanical ar- TF cycle cycle rangement.

Inherently self cooled design. Walls see Ports to and from combustor are on opposite ends hot/cold flow at 265 Hz.

of rotor for the two cycles complicating ducting to and from rotor.

Turbine ports are on opposite ends of rotor for the two cycles complicating ducting from rotor to tur- bine.

Table III. Wave Rotor Design Summary.

Rotor Dimensions As Designed: Inlet Port Area, A1, 4.3 sq in.

Mean Radius 3.21 in.

Passage Height 0.8792 in.

Rotor Length 6.0 in.

Design Point Parameters: cycles per revolution 2 rotor speed 16800 rpm passages 52 ratio of specific heats 1.353 viscosity 2.734X 10-5 lbm/ft/sec mean Prandlt no. 0.75 P4/P1 1.219 T4/T1 2.210 mass flow 4.785 lbm/sec Q 2.155 COlT 0.465 moo= Rotor Dimensions As Scaled To Achieve Matched Flow Capacity: Inlet Port Area, A1, 4.595 sq in.

Mean Radius 3.21 in.

Passage Height 0.9294 in.

Rotor Length 6.0 in.

Match Point Operating Parameters cycles per revolution rotor speed 16067 rpm passages 1.353 ratio of specific heats 2.734X 10-5 lbm/ft/sec viscosity mean Prandlt no. 0.75 P4/P1 1.237 T4/T 1 2.245 mass flow 4.827 lbm/sec 2.149

Q

con" 0.450 mcolT Table IV. Estimated Fabrication and Program Costs.

Cost ($) Adaptive engine parts required, 3 assemblies: 122100 A1.

Gasifier turbine rear bearing support 57800 A2.

Nozzle assembly- gasifier turbine 1st stage 40900 A3.

Shield - gasifier turbine bearing sump 27800 A4. Combustor case 36900 A5. Combustor liner A6.

Misc. exterior pipes and wiring A7.

Spacer- turbine containment ring 11600 A8.

Turbine nozzle mounting flange and support A9.

Engine mount A10.

Misc. parts in gasifier turbine sump $ 322,000 Total adaptive engine parts Cost ($) Wave Rotor Components required, 3 assemblies: 73400 I. Rotor 45300 2. Forward end plate 45300 3. Rear end plate 4. Air bearing journal shaft 21100 5. Outer wave rotor assembly case 440O 6. Inner case tube 33600 7. Air bearing components 93100 8. Transition ducts - compressor to port 1 57700 9. Transition case - combustor to wave rotor 15300 10. Combustor center body 11. Support for combustor center body 5700O 12. Duct from combustor outlet annulus to port 2 116300 13. Duct from port 5 to combustor case inlet 14. Intermediate flange - liner support at combustor flange $581,000 Total Wave Rotor Components Total Pro_am Cost $246,000 Program Management $153,000 General Layout Design and Analysis $322,000 Total adaptive engine parts $581,400 Total Wave Rotor Components $236,000 Basic Conventional Engine Components $28,100 Engine Assembly, 10 builds $48,800 Test Costs Misc. $161,500 $1,776,800 Total Cost 250-C30 EXHAIJ COLLECTOR SUPPORT OUTER PBIIIUSTION CASE

\

GAS PRODUCER TURBINESUPPORT POWER TURBINESUPPORT COIIPRESSOR FRONTSUPPORT COMPRESSOR DISCHARGE AIR TUBE ACCESSORY GEARBOX Figure 1. Allison 250-C30 Turbo-Shaft Engine.

2../Z"_-_ I

o F'OWpASSAG

T

END PLATE r,l"--%.'_u_,___

ROTOR -"_ _]__._ j_ _5__

Port 2: Flow From Burner

Port , • Flow From Compressor L,_ _i/_4 _ '

Port 4: Flow To Turbine

Port 5: Flow To Burner END PLATE _

Figure 2. Schematic of Wave Rotor Configuration.

[_ Burner_ _,_ 5_l !

_] ..R0tor,_

4 Compressor

Tur

Figure 3. Wave Rotor With Through Flow Cycle Used As A Gas Turbine Topping Cycle.

To Burner From Burner To Turbine From Compressor Figure 4. Wave Diagram Of The Selected Four-Port Through-Flow Wave Rotor Cycle.

Expansion Pressure Veloci Density Hot - Cold 8 F Gas Interface ( To Burner = _: r_ From Burner _a o From Compressor 2 0 0 Expansion 0.(1 0.5 _1.0 ne 0.0 0.5 1.0 0.0 0.5 1.0 x/L x/t, ×/T.

Figure 5. Wave Diagrams Of The Engine Topping Cycle, Pressure, Density, and Velocity Con- tours.

1.5

/

1.4

/

o" o--

/

1.3

/

e'l

/

1.2

/

-i

/

/ o

GE experiment o !

/

PR = 1.8 1.1 tXl CFD code results Advanced rotor PR = 3.6)

I I ! I

1.0 2.0 2.5 3.0 3.5 1.5 Wave-rotor temperature ratio, T4/r3 Figure 6. Pressure ratio across wave rotor as a function of temperature ratio across it from reference 1. Solid line characteristic used.

Through Flow Rotor

@

t- O To o3 ;ombustor O EL m From ¢-.

E

1 4 o L_

x/L

Reverse Flow Rotor

E

x/L

Figure 7. Wave Diagram Comparison Of The Through-Flow And Reverse-Flow Cycles.

Reverse Flow Rotor

To Combustor

O mm im Q.

qll_2

From Combustor

E 1

t__

O

To Combustor

2_

From Combustor

x/L

Figure 8. Reverse-Flow Rotor With Alternately Right And Left Porting.

Freewheeling Wave Rotor

Model 250 Demonstrator 1.40 ,Ir..!_.--ly----¥ ...... ¥ .............

r 1.30

S

P4/P1 414_ - v/ Ratio specific heats 1.20 Qcorr Qcorr/Qcd 0.50 1.077,

/

0.75 "lk,I, 1.616,

• r •

÷ i 2.155, 1.00 J 1.10 2 6_4 _ "_ z ![,• 3.233, 1.50 1.00 2 3 4 T4Prl Data from D. Paxson 2/24/95 Figure 9. Performance Of Rotor Designed For Use In Demonstrator Engine, Pressure Gain.

Freewheeling Rotor

1.5 Gamin a=1.3_ 1.4 Ocorr = 3.23!

_corr = 2.694 1.3 Qcorr = 2.155 I Qcorr = 1.616 1.2 Qcorr = 1.0' 1.1 0.6 0 0.1 0.2 0.3 0.4 0.5 Correct (dimensionless) Flow Rate Figure 10. Performance Of Rotor Designed For Use In Demonstrator Engine, Mass Flow.

7.75 lbm/sec

.. 381 psia

/ 347psia _ 1767F

Burner _-_605 F

I 2"_1-- .............. , I _14.7 psia

Con" Mass Flow" I W_i;e% / 1067F 14.790.0 psiaF

n450 _ _ "2%.._1 140psia I

Qcorr = 2.149 1730 F A Compr

113 psia ,_ !

621F _ /

j I '

c28c !

Turbine

4.83 lbm/sec

Demonstrator Engine Design Point, Through Flow Cycle Conditions.

Figure 11.

30.0% idle 20.0% i _=

• • •

e" 10.0% ID 0.0% .......................

-10.0% r/l -20.0% • • • @ • t_ ca -30.0% idle I P.

t_ -40.0% 0 100 200 300 400 500 600 700 Shaft Power Output, (hp) Comparison of Off Design Performance To Baseline Engine Performance.

Figure 12.

3.8 2.0 1.9 .................................................. X_- Y O.

.......................... :............. :"-..:....................................

3.4 1.8 L DesignPoint_Q _: ;& i T..

L Take Off I_:,; _ ": @._ • _ ql_ t..xCru,.oJ . '" .............

i .,% 1.7 ..... C.lrui,_ A-_ ............. :.,........................................ _,,,--- 3.2 Cruise B-- Z • .... • .......

50% SHP/t • @. " ............

,. . -.. "-,

_J

,._ _._ ..................... +.-.:.._. ................... _.-.:-.:_ ....................... . ..........................

3.0 Idle \ +. '"e ::

+. ........ i + + ............ i

2.8 1.s ................ _--_---_ .......... 2.-: ............ i................... :_ ..... ;: ..........................

"dk.. ', i_ "'" ,, "'"_ki ............. m__ I_ ..... : ........................... .: ............................ ; ...........................

1.4 2.6 ' i o°, oo, 1.3 2.4 ..... Design-Point\-- ............ _-- ..... _i ................ I_ 1 616 075 Take Off_ \ __I_ " ' " Max Cruise \:_ _- J i Cruise A\ ,:_ __ _ :: / % 2 155 1 O0

E

..... Cr.i...._i ................ _-- " ' "

2.2 _ 1.2

t ! i

1.1 Idle ..._._.i_._ t ...... I ............ !................ /%3.233, 1.50 2.0 Ira-] i :_ :: |_i, Topped Engine t I i " ! [ _" OperatingP°ints .... _,.i ......... i ..... ---: ........

1.0 1.8 2 3 4 Wave Rotor Temperature Ratio, T4FF 1 Figure 13. Placement Of Operating Points On Freewheeling Wave Rotor Performance Map.

Cycle Pressure Ratios

T ipped Cycle,Slaft Compr.

T ,ppedCycle,V_ave Rotor _k p oductionEngire OX,=T ,nn,_rl _vnl_ (2, vAmll 2O 'qv f= ,r , / j__4,- --1 .I "_ ._._....._-_ [] - _- [] _-II 100 200 300 400 500 600 700 80O Engine Power Output, hE Figure 14. Cycle Pressure Ratios Of The Wave Rotor Topped Demonstrator Engine.

1.40 1.32 1.24 .---41 _J P4/P1 X j 1.16 J 1.08 1.00 0 100 200 300 400 500 600 Engine Shaft Power Output, hp Figure 15. Overall Wave Rotor Pressure Gain For The Demonstrator Engine.

Hot Gas Expansion Within Wave Rotor

Temperature Reduction

_J

/ "_ 500 r" m [- 400 I ._ X

E

7OO 8OO 100 200 300 400 500 600 Engine Power Output, hp Figure 16. Drop In Gas Temperature From Burner Exit To Turbine Inlet.

Wave Rotor Gas Temperatures

ComparedWith ProductionEngineGas Temperatures

/, / Burner Inli,=t, WR topped . /// 2800 4",l,TurbineInlet,WR toppec tI_4_,j.._ 1t BurnerExt, WRtopped 2600 _,j_ / &_TurbineInlet, Production

= 2400 /......._- , .+

2000 . _.......... %1;iii_

o

r_ 1800 1400 _'":"" " l 0 100 200 300 400 500 600 700 800 Engine Power Output, hp Figure 17. Gas Path Temperatures In The Topping Cycle.

Burner Inlet Temperature Comparison

Wave Rotor Topped Engine And Production Engine

25OO _ Producti_ _n Engine WRToPl _ed Engine .2, 2OOO

/

E

E- / "E e- 1000 f / 3OO 400 500 600 700 800 0 100 200 Engine Power Output, hp Burner Inlet Temperature Comparison.

Figure 18.

Ratio of Ngg to N Wave Rotor

3.6 3.2 Z 2.8

II

II 2.4 100 200 300 400 500 600 700 800 Engine Power Output, hp Figure 19. Comparison Of Rotational Speed Of Gasifier Spool and Wave Rotor.

Rotor Dimensions

Density Wave Diagram

"-- 6.0 in--_

Rotor Speed

to burner

16800 rpm

3.21 in

.... .............

86 in

2 from burner 4 to turbin_

I'

1 from

P=379.7 psia

T=2193.7 R

m=3.694 Ibm/s

P=344.6 psia

T=3041.0 R

P=140.33 psia

m=3.694

T=2389.5 R

P= 114.2 psia

m=2.393 Ibm/s

T=1081.7 R

m=2.393 Ibm/s

Figure 20. Wave Rotor Design, Wave Diagram and Rotor Dimensions:

Rotor Designed For Use In

Allison 250 Wave Rotor Demonstrator Engine

End Plate

Port Spacing

Inlet End

Outlet End

1 from compressor 2 from burner 4 to turbine 5 to burner Figure 21. Wave Rotor Design, Rotor End View.

Rotor Designed For Use In

Allison 250 Wave Rotor Demonstrator Engine

End View of Rotor 52 passages 12% Blockage due to Passage Walls Figure 22. Wave Rotor Design, End Plate Port Location.

U

I 0 0 0

o IZ W

I

i0

E ----4

!

|

Im 14q °_

e

E

iI 0_ Ill I o Z 0 0 0 Z o _=

0 0

9 0 C C 9 I o_ O Q o_ .-I o_ I Combustor Added Here Additional Manifold Here Figure 26. An Early Engine Layout Concept

;m

.,,,_ <ll I t_ I-i liJ E t--: t",,i ° ,+,,-i IT,.

Figure 28. Port 1 Preliminary Design.

i k k tu Q e" °_ ,..1 _u

\

k t_ ,_J Z.

t

/ / / /

!

\"\\

/

&q.B7 ° / //_ <.., ".

/ 20.72 0 %

-

\ t4_ °

, \

/ I _,, Port 2 Side And End Views.

Figure 30.

O _j _J L_ _.=., c_ _J q: _J _J L_ _J ,J ! / /I FL Ot,/ NOF6: D_Cr fLO_/ P._FN CO._'FOCJ_ $_O_A/ 83" &f.&° \ Po_r do=. 4- ¢ g o_,e,er_r,o_/ ° I/1_1_ Loo/ct,/_ _-oWt./m_b 0 -- __0 ° _. 21. G ° &l.G ° 93" Figure 32. Port 3 Side And End Views.

I

\

/

l

_4 o_ .,._ o_

I

\

Figure 34. Cutaway View Of Wave Rotor Module Preliminary Design, Side View.

/ Figure 35. Cutaway View Of Wave Rotor Module Preliminary Design, End View.

1.0 Y

0.8

0.6

O O

O 0.4

0.2 0.0 _ I i t

1000 1500 2000 2500 3000

Absolute Stagnation Temperature (deg. R)

Figure 37. Port 5 Stagnation Temperature Distribution.

r..)

E ¢) O L, E-- L_ oa

t

oo L"- _s c_ Lt_ ua C_ O,I °_ O0 U_ L.

L_ _s _t_ <: o< L,

U_

f_ _S olm,_ <: _4 _q Appendix A. NASA Generated Wave Rotor Design.

Optimized 250 Wave Rotor An optimization procedure was performed for an Allison 250 based, 4-port, through-flow wave rotor (originally designed for approximately 4.0 Ibm/s). Little performance difference was found between one and two cycle per rotor revolution designs. The two cycle design was selected because a) it commensurate with the ducting from the 250 compressor and b) it maintains the option of a reverse flow design if further investigation shows that cycle to be superior. The relevant geometry and design point information are presented below and shown in Figures 1-3.

radius=3.21 in.

length=6.0 in.

cycles per revolution=2 omega=16800 rpm passage height=0.86490 in mass flow--4.785 lbm/s passages=52 passage width= 0.3445 in web thickness=0.0434 in ratio of specific heats=1.353 P°i.l,t=114.2 psia (reference pressure) T°t.,et=1081.7 R (reference temperature) T°e_=2390 R P/P1=1.229 T/r1=2.209 viscosity=2.734 X 10 "s Ibm/ft/s (based on mean of inlet and exhaust) mean Pandtl #=.750 web blockage=12.6 % inlet port area=4.23 sq. in.

Below is sample output of the supplementary data for the design point.

T05 WDOTIN EPSLON QCORR MFFRAC MFC PR TR OMEGA P02 T02 P05 2.028 0.000 0.405 2.188 1.544 0.472 1.229 2.209 0.550 3.017 2.811 3.325 All of the data has been normalized by the inlet state shown above. The first column is the corrected heat addition which is defined as QCORR = P01Al _ gc where A t is the inlet port area shown above, R is the real gas constant, P0_ and T01 are the inlet stagnation pressure and temperature, (_ is the heat additions rate, and g_ is the Newton constant. The secon column is the ratio of upper loop flow over throughflow. The third column is the corrected flow rate defined as MFC* PolA1 where 41 is the mass flow rate. The values for PR and TR are the ratios of stagnation pressure and temperature across the entire machine (see Fig 3). OMEGA is the rotor non-dimensional rotor speed defined as caL OMEGA = -- where L is the rotor length, and ao_ is the inlet stagnation speed of sound. P02 and T02 are the stagnation pressure and temperature coming from the burner (normalized by the inlet from the compressor-1). P05 and T05 represent the flow going to the combustor. EPSLON is the ratio of the exhaust port smile pressure over the average pressure in the passage just before the exhaust port opens. The plots appearing in Figures 4-6 are reasonably self-explanatory. Leakage gaps of 0.005 in. were assumed since that is approximately where the NASA Phase 1 rotor is currently operating.

The web blockage listed above should be used when calculating mass flows. That is, the mass flow obtained from the corrected flow rate above and the known area and inlet state should be reduced by 12.6% to get the true mass flow (this has worked well for the NASA experiment to date).

Note that Figures 4-6 are for a freewheeling wave rotor. It is not clear that this approach will work however, because it appears that as fuel flow is increased (i.e., increased heat addition) the corrected flow is reduced. This would seem to be precisely the opposite of what the surrounding turbomachinery requires. As such, maps and data which correspond to holding the rotor at fixed speeds are also included. The plots in Figures 7-10 show the performance on mass flow vs. pressure ratio curves for families of speed lines at 4 different fuel flow (heat addition) settings. Temperature ratio information can be found in the supplementary data. Note that the fixed speed supplementary data conatains an extra column entitled WDOTIN. This is the ratio WDOTIN cpTol The speed labels on Figures 7-10 which have a (p) next to them indicate positive shaft work (i.e. a drive motor is required) all the rest show work is being extracted from the shaft.

Freewheel Performance Data QCORR MFFRAC MFC PR TR OMEGA P02 T02 P05 T05 1.0775 0.9392 0.4992 0 9920 1.5654 0.4810 2.4442 2 4894 2.5980 1.8900 0248 1.5704 0.4716 2.5107 2 4745 2.6630 1.8870 1.0775 0.9682 0.4941 1 5219 2.6840 1.9250 0522 1.5863 0.4680 2.5327 2 1.0775 0.9854 0.4780 1 5401 2.6880 1.9510 0711 1.6259 0.4677 2.5298 2 1.0775 1.0686 0.4468 1 0872 1.6997 0.4638 2.4959 2 5417 2.6610 1.9650 1.0775 1.2210 0.3993 1 5833 2.6280 1.9980 0928 1.7437 0.4634 2.4630 2 1.0775 1.2790 0.3755 1 7168 2.5490 2.0980 0981 1.8317 0.4675 2 3895 2 1.0775 1.3558 0.3352 1 7846 2.7780 1.9970 0290 1.8532 0.5309 2 5607 2 1.6163 1.0790 0.4960 1 6608 2.8750 1.9370 6452 2 1.6163 1.1814 0.4935 1.0594 1.8574 0.5227 2 5458 2.9980 1.8840 7581 2 1 6163 1.2983 0.4906 1.0940 1.8624 0.5110 2 8280 2.5362 3.0650 1.8850 6163 1.3335 0.4856 1.1290 1.8701 0.5023 2 8501 2.6009 3.0810 1.9270 6163 1.3471 0.4648 1.1576 1 9048 0.4946 2 )341 0.4956 2 8374 2.6203 3.0700 1.9440 6163 1.3863 0.4497 1.1643 1 8138 2.6377 3.0520 1.9630 9812 0.4988 2 6163 1.4590 0.4282 1.1716 1 7844 2.6681 3.0270 1.9900 0365 0.5021 2 6163 1 5340 0.4054 1.1782 2 0920 0.5064 2 7513 2.7155 2.9960 2.0280 5936 0.3847 1.1840 2 6163 1 7123 2.7832 2 9570 2.0790 1561 0.5122 2 6163 1 6484 0.3633 1.1900 2 6696 2.8725 2 9120 2.1460 2297 0.5195 2 6163 1 6989 0.3416 1.1961 2 3165 0.5290 2 6221 2.9849 2 8610 2.2310 7532 0.3189 1.2016 2 6163 1 5712 3.1314 2 8030 2 3420 4281 0.5406 2 6163 1 8187 0.2939 1.2066 2 5188 3.3338 2 7390 2 4990 5846 0.5547 2 6163 1 9081 0 2647 1.2106 2 4331 3.7341 2 6330 2 8100 8990 0. 782 2 0712 0 2203 1.2088 2 6163 2 5886 2.7533 3.1525 3 0140 2 4834 1.0623 2 1613 0 2 1550 1 1863 0 5875 2.7763 3.1292 3 0400 2 4814 1.0854 2 1673 0 2 1550 1 2153 0 1660 5847 2.7952 3.1128 3 0610 2 4783 1.1129 2.1749 0 2 1550 1 2420 0 5789 2.8311 3.0564 3.1030 2 4744 1.1438 2.1881 0 2.1550 1 2986 0 1040 5692 2.8758 2.9721 3.1560 2 4695 1.1799 2.2013 0 2.1550 1 3790 0 5640 2.8994 2.9320 3.1840 2 4677 1.1961 2.2063 0 2.1550 1 4196 0 5453 3.0184 2.8084 3.3230 2 4650 1.2217 2.2122 0 2.1550 1 5642 0 5307 3.0752 2.8397 3.3800 2 0630 4490 1.2386 2.2504 0 2.1550 1 6112 0 5362 3.0480 2 8814 3.3540 2.0960 4342 1.2440 2.2913 0 2.1550 1.6482 0 5420 3.0199 2 9319 3.3280 2.1370 4182 1.2487 2.3410 0 2.1550 1.6912 0 5477 2.9908 2 9966 3.3010 2.1890 2.1550 1.7407 0.3998 1.2536 2.4026 0 5545 2.9577 3 0757 3.2680 2.2510 2.1550 1.7946 0.3799 1.2587 2.4760 0 1673 3.2280 2.3220 2.1550 1.8510 0.3595 1 2636 2.5600 0.5629 2.9190 3 2827 3.1780 2.4110 2672 2.6651 0.5738 2.8702 3 2.1550 1.9162 0.3367 1 4319 3.1170 2.5250 2701 2.8000 0.5873 2.8124 3 2.1550 1.9922 0.3113 1 6346 3.0420 2.6810 2717 2.9822 0.6053 2.7433 3 2.1550 2.0869 0.2826 1 9392 2.9460 2.9170 2711 3.2524 0.6313 2.6576 3 2.1550 2.2143 0.2485 1 5483 2.8030 3.3800 2670 3.7692 0.6737 2.5371 4 2.1550 2.3867 0.2016 1 3117 3.3110 2.2460 1065 2.4854 0.6244 2 9928 3 2.6937 1.3970 0.4721 1 0178 3.2939 3.3400 2.2460 1264 2.4932 0.6236 3 2.6937 1.4257 0.4705 1 0446 3.2769 3.3710 2.2490 1508 2 4997 0.6229 3 2 6937 1.4627 0.4673 1 0705 3.2650 3.4010 2.2550 5124 0.6215 3 6937 1.5003 0.4639 1.1769 2 0888 3.2607 3.4230 2.2640 5298 0.6196 3 6937 1.5354 0.4592 1.2052 2 5375 0.6185 3 0922 3.2626 3 4280 2.2680 6937 1 5469 0.4569 1.2172 2 1010 3.2629 3 4370 2.2750 5484 0.6169 3 6937 1 5688 0.4533 1.2335 2 5608 0.6158 3 1093 3.2640 3 4480 2.2820 6937 1 5918 0 4498 1.2487 2 1148 3.2675 3 4550 2.2910 5727 0.6151 3 6937 1 6112 0 4464 1.2616 2 1186 3.2746 3 4590 2 3010 5864 0.6147 3 6937 1 6314 0 4425 1.2743 2 1238 3.2819 3 4650 2 3130 6009 0 6132 3 6937 1 6539 0 4384 1.2881 2 1314 3.2979 3 4720 2 3290 6304 0 6045 3 6937 1 6842 0 4305 1.3046 2 6080 3.0926 3.3698 3 4340 2 3780 4125 1.3109 2.6995 0 2.6937 1 7183 0 6160 3.0529 3.4560 3 3950 2 4410 3944 1.3150 2.7785 0 2.6937 1 7556 0 3742 1.3190 2.8746 0 6249 3.0125 3.5587 3.3550 2 5190 2.6937 1 8057 0 6364 2.9652 3.6950 3.3090 2 6230 3509 1.3217 2.9975 0 2.6937 1 8678 0 6514 2.9099 3 8733 3.2540 2.7600 3246 1.3232 3.1594 0 2.6937 1.9450 0 6723 2.8435 4 1279 3.1850 2.9590 2935 1 3226 3.3881 0 2.6937 2.0480 0 6658 3.2029 3 6576 3.5710 2.4710 4619 1 1437 2.8261 0 3.2325 1.5396 0 6699 3.2098 3 6643 3.5800 2.4830 1612 2.8349 0 3.2325 1.5571 0.4583 1 3.2325 1.5791 0.4565 1 1818 2.8441 0.6698 3.2308 3 6639 3.6030 2.4930 3.2325 1.6063 0.4538 1 2051 2.8575 0.6708 3.2530 3 6661 3.6290 2.5080 3.2325 1.6423 0.4491 1 2320 2.8749 0.6716 3.2758 3 6745 3.6560 2.5300 3.2325 1.6574 0.4468 1 2431 2.8834 0.6717 3.2838 3.6795 3.6660 2.5400 3.2325 1.6780 0.4435 1 2574 2.8986 0.6725 3.2929 3.6895 3.6770 2.5560 3.2325 1.6976 0.4400 1 2713 2.9124 0.6726 3.3003 3.6994 3.6870 2.5700 3.2325 1.7106 0.4371 1.2831 2.9262 0.6725 3.3025 3.7081 3.6910 2.5800 Freewheel Performance Data 3 2325 1.7225 0.4342 1.2959 2.9384 0.6709 3 3039 3.7161 3.6920 2.5880 3053 3.7273 3.6960 2.6000 2325 1.7375 0.4306 1.3087 2 9535 0.6701 3 9714 0.6697 3 3063 3.7414 3.6970 2.6150 2325 1.7544 0.4268 1.3211 2 9937 0.6693 3 3067 3.7610 3.6980 2.6340 2325 1.7737 0.4221 1.3335 2 3043 3.7894 3.6940 2.6590 0236 0.6685 3 2325 1.7947 0.4160 1.3454 3 0796 0.6697 3 2826 3 8486 3.6700 2.7010 2325 1.8164 0.4045 1.3547 3 1738 0.6774 3 2328 3 9503 3.6170 2.7670 2325 1.8401 0.3872 1.3590 3 1687 4 0890 3.5510 2.8580 2325 1.8716 0.3660 1.3610 3 2985 0.6896 3 4706 0.7047 3 0870 4 2811 3.4670 2.9850 2325 1.9093 0.3407 1.3619 3 9799 4 5679 3.3540 3.1770 7204 0.7282 2 2325 1.9597 0.3094 1.3597 3 0979 0.7614 2.8560 5 0090 3.2180 3.4850 2325 2.0391 0.2714 1.3558 4 7294 0.8048 2.7431 5 7203 3.0890 4.0310 2325 2.2180 0.2250 1.3516 4 Fixed Speed Performance Data QCORR MFFRAC MFC PR TR OMEGA P02 T02 P05 T05 WDOTIN 1.616 1.179 0.521 1.037 1 804 0.440 2.892 2 455 3.124 1.768 -0.006 806 0.440 2.899 2 463 3.130 1.773 -0.006 1.616 1.178 0.519 1.047 1 1.616 1.180 0.515 1.067 1 811 0.440 2.911 2 479 3 140 1.786 -0.006 1.616 1.185 0.508 1.088 1 822 0.440 2.919 2 503 3 146 1.803 -0.006 842 0.440 2.915 2 535 3 144 1.825 -0.006 1.616 1.199 0.495 1.109 1 881 0.440 2.899 2 562 3 131 1.848 -0.006 1.616 1.248 0.473 1.125 1 1.616 1.276 0.506 1.013 1 834 0.495 2.748 2 466 2 985 1.812 -0.002 835 0.495 2.762 2 465 3 000 1.814 -0.002 1.616 1.284 0.505 1.028 1 838 0.495 2.785 2 468 3 023 1.820 -0.002 1.616 1.297 0.502 1.050 1 1.616 1.309 0.499 1.076 1 843 0.495 2.810 2 478 3 048 1.833 -0.002 850 0.495 2.834 2 498 3 071 1.851 -0.001 1.616 1.319 0.494 1.104 1 1.616 1.328 0.486 1.133 1 865 0.495 2.853 2 533 3 087 1.879 -0.001 904 0.495 2.850 2 600 3 081 1.927 0.000 1.616 1.348 0.465 1.158 1 937 0.495 2.838 2 620 3 071 1 943 0.000 1.616 1.389 0.449 1.164 1 1.616 1.476 0.422 1.171 1 )94 0.495 2.813 2 637 3 053 1 )61 -0.001 692 3 017 2 001 -0.002 1.616 1.560 0.391 1.177 2 071 0.495 2.771 2 162 0.495 2.717 2 796 2 963 2 071 -0.003 1.616 1.617 0.360 1.182 2 1.616 0.911 0.495 1.001 1 852 0.550 2.435 3.108 2 631 2 172 0.001 655 2 166 0.001 1.616 0.936 0.492 1.020 1 857 0.550 2.455 3.081 2 865 0.550 2.486 3.047 2 690 2 159 0.002 1.616 0.974 0.488 1.046 1 875 0.550 2.524 3.015 2 733 2 157 0.002 1.616 1.017 0.483 1.074 1 887 0.550 2.565 2.981 2 780 2 154 0.003 1.616 1.069 0.477 1.106 1 )05 0.550 2.608 2.964 2 825 2 162 0.004 1.616 1.123 0.468 1.138 1 915 0.550 2.623 2.968 2 839 2 172 0 004 1.616 1.145 0.463 1.151 1 855 2 186 0 005 1.616 1.181 0.452 1.166 1 936 0.550 2.638 2.976 2 972 0.550 2.648 2.963 2 869 2 188 0 OO6 1.616 1.249 0.436 1.176 1 1.616 1.334 0.418 1.183 2 013 0.550 2.652 2.935 2 879 2 179 0 006 886 2 171 0 006 1.616 1.429 0.400 1.190 2 060 0.550 2.654 2.909 2 117 0 550 2.651 2.892 2 887 2 168 0 006 1.616 1.538 0.379 1.196 2 1.616 1.668 0.353 1.203 2 197 0 550 2.641 2.898 2 880 2 181 0 005 343 0 550 2.598 3.006 2 834 2 264 0 003 1.616 1.812 0.314 1.207 2 069 0 440 3.177 2.682 3 472 1 843 -0 009 2.155 1.286 0 522 1.110 2 475 1 845 -0 009 2.155 1 288 0 521 1.117 2 071 0 440 3.182 2.684 3 440 3.192 2.693 3 484 1 852 -0 OO8 2.155 1 295 0 516 1.136 2.079 0 2.155 1 305 0 509 1.155 2.094 0 440 3.197 2.710 3.488 1 864 -0 440 3.189 2.737 3.482 1 882 -0 0O9 2.155 1 325 0 496 1.173 2.120 0 472 1.186 2.176 0 440 3.158 2.783 3.458 1.914 -0 010 2.155 1 372 0 440 3.070 2.896 3.377 1.987 -0 010 2.155 1 445 0 428 1.192 2.296 0 O05 2.155 1 430 0 506 1.090 2.106 0 495 3.087 2.709 3.384 1.932 -0 495 3.096 2.709 3.394 1.933 -0 0O5 2.155 1 435 0 505 i.i01 2.109 0 OO5 444 0 504 1.121 2.114 0 495 3.112 2.709 3.412 1.935 -0 2.155 1 OO5 2.155 1 453 0 501 1.145 2.118 0 495 3.131 2.711 3.433 1.939 -0 496 1.172 2.128 0 495 3.148 2.722 3.450 1.947 -0 OO5 2.155 1 463 0 2.155 1 476 0 487 1.198 2.150 0 495 3.158 2.745 3.458 1.963 -0 510 0 463 1 219 2.205 0 495 3.136 2.806 3.438 2.001 -0 2 155 1 444 1 223 2.257 0 495 3.109 2.854 3.418 2.037 -0 006 2 155 1 551 0 416 1 228 2.341 0 495 3.065 2.937 3.382 2.098 -0 007 2 155 1 611 0 495 2 995 3.064 3.316 2.182 -0.009 2 155 1 670 0 381 1 234 2.459 0 235 2.586 0.495 2 921 3.203 3.234 2.264 -0.009 2 155 1 708 0 351 1 493 1 066 2.141 0.550 2 868 2.839 3.148 1.991 -0.003 2 155 1 345 0 084 2.145 0.550 2 877 2.840 3.158 1.995 -0.003 2 155 1 355 0 491 1 107 2.149 0.550 2 889 2.840 3.171 2.000 -0.003 2 155 1 370 0 489 1 2 155 1 393 0 485 1 133 2.157 0.550 2 905 2.838 3.189 2.006 -0.002 161 2.170 0.550 2 925 2 833 3.212 2.012 -0.001 2 155 1 428 0.480 1 481 0.473 1 191 2.187 0.550 2.955 2 824 3.248 2.021 -0.001 2 155 1 204 2.195 0.550 2.969 2 821 3.266 2.027 -0.001 2 155 1.507 0.470 1 822 3.289 2.037 0.000 220 2.208 0.550 2.988 2 2 155 1.541 0.465 1 234 2.226 0.550 3.003 2 834 3.305 2.052 0.001 2 155 1.570 0.458 1 244 2.254 0.550 3.009 2 856 3.312 2.073 0.002 2.155 1.603 0.448 1 907 3.309 2.116 0.001 2.155 1.663 0.428 1 249 2.313 0.550 3.003 2 254 2.393 0.550 2.989 2 986 3.298 2.181 0.000 2.155 1.734 0.403 1 258 2.505 0.550 2.955 3 108 3.267 2.272 -0.001 2.155 1.806 0.372 1 263 2.682 0.550 2.874 3 307 3.187 2.399 -0.004 2.155 1.866 0.332 1 054 2.166 0.605 2.653 3 434 2.897 2.326 0.002 2.155 1.053 0.482 1 406 2.923 2.322 0.002 077 2.175 0.605 2.676 3 2.155 1.084 0.479 1 429 2.929 2.345 0.002 2.155 1.094 0.474 1.103 2.186 0.605 2.682 3 2.155 1.107 0.469 1.132 2.200 0.605 2.686 3.458 2.934 2.373 0.002 2.155 1.136 0.462 1.164 2.219 0.605 2.699 3.466 2.950 2.394 0.002 Fixed Speed Performance Data 2.155 1.152 0.459 1.178 2.228 0 605 2 706 3.466 2.959 2.402 0.003 2.155 1.181 0.454 1.195 2.240 0 605 2 719 3.454 2.975 2.406 0.003 738 3.425 2.998 2.399 0.004 2.155 1.220 0.449 1.210 2.256 0 605 2 2.155 1.256 0.444 1.223 2.272 0 605 2 755 3.405 3.017 2.397 0.004 2.155 1.288 0.435 1.234 2.297 0 605 2 762 3.411 3.025 2.408 0.005 605 2 759 3.412 3.027 2.417 0.006 2.155 1.344 0.420 1.243 2.342 0 2.155 1.428 0.403 1.250 2.399 0 605 2 758 3.386 3.033 2.410 0.006 605 2 758 3.355 3.040 2.400 0.005 2.155 1.529 0.385 1.257 2.464 0 2.155 1.653 0.365 1.265 2.544 0.605 2 757 3.330 3.046 2.397 0.005 2.155 1.829 0.338 1.270 2.664 0.605 2 762 3.335 3.059 2.426 0.004 742 3.641 3.040 2.685 0.000 2.155 2.087 0.282 1.272 2.988 0.605 2 346 6.643 2.524 4.412 0.010 2.155 0.586 0.429 1.082 2.322 0.715 2 2.155 0.548 0.436 1.048 2.300 0.715 2 301 6.816 2.475 4.455 0.011 347 6.643 2.523 4.413 0.010 2.155 0.587 0.429 1.082 2.321 0.715 2 2.155 0.629 0.423 1.118 2.341 0.715 2 392 6 481 2.573 4.372 0.011 435 6 459 2.618 4.413 0.013 2.155 0.661 0.415 1.154 2.368 0.715 2 449 6 448 2.636 4.424 0.014 2.155 0.681 0.407 1.165 2.397 0.715 2 459 6 381 2.654 4.404 0.015 2.155 0.721 0.394 1.177 2.445 0.715 2 2.155 0.771 0.381 1.187 2.496 0.715 2 462 6 254 2.666 4.338 0.016 2.694 1.312 0.520 1.176 2.340 0.440 3 413 2 997 3.761 1.968 -0.011 417 2 999 3.765 1.969 -0.011 2.694 1.316 0.519 1.182 2.342 0.440 3 423 3 010 3.770 1.977 -0.011 2.694 1.326 0.513 1.200 2.357 0.440 3 2.694 1.341 0.503 1.217 2.381 0.440 3 419 3 032 3.767 1.991 -0.011 395 3 076 3.748 2.021 -0.012 2.694 1.369 0.486 1.231 2.427 0.440 3 359 3 056 3.709 2.116 -0.009 2.694 1.474 0.507 1.157 2.377 0.495 3 2.694 1.479 0.506 1.172 2.379 0.495 3 369 3 052 3.720 2.113 -0.009 383 3 049 3.737 2.111 -0.009 2.694 1.485 0.505 1.193 2.384 0.495 3 052 3.752 2.112 -0.009 2.694 1.490 0.502 1.216 2.391 0.495 3 397 3 406 3 064 3.761 2.118 -0.008 2.694 1.499 0.495 1.240 2.409 0.495 3 2.694 1.516 0.481 1.262 2.447 0.495 3.398 3 I01 3.753 2.138 -0.008 220 3.716 2.225 -0.011 2.694 1.582 0.446 1.273 2.559 0.495 3.348 3 108 3.545 2.183 -0.007 2.694 1.542 0.492 1.136 2.417 0.550 3.205 3 2.694 1.558 0.491 1.149 2.421 0.550 3.223 3 108 3 566 2.190 -0.007 597 2.201 -0.006 2.694 1.581 0.489 1.170 2.428 0.550 3.250 3 110 3 632 2.215 -0.006 2.694 1.608 0.487 1.194 2.437 0.550 3.281 3 113 3 668 2.228 -0.005 2.694 1.635 0.483 1.221 2.449 0.550 3.312 3.119 3 697 2.242 -0.005 2.694 1.659 0.478 1.251 2.464 0.550 3.337 3.128 3 704 2.248 -0.004 2.694 1.667 0.475 1.263 2.473 0.550 3.344 3.137 3 708 2.260 -0.004 2.694 1.677 0.469 1.278 2.492 0.550 3.348 3.153 3 700 2.279 -0.003 2.694 1.688 0.459 1.290 2.525 0.550 3.341 3.187 3 675 2.323 -0.004 2.694 1.712 0.440 1.295 2.588 0.550 3.313 3.256 3 651 2.392 -0.006 2.694 1.755 0.417 1.300 2.673 0.550 3.283 3.352 3 608 2 478 -0.008 2.694 1.800 0.390 1.305 2.789 0.550 3.236 3.480 3 537 2 585 -0.011 2.694 1.843 0 358 1.311 2.945 0.550 3.162 3.651 3 362 2 796 -0.014 2.694 1.883 0 304 1.308 3.282 0.550 3.004 4.023 3 391 2 201 -0.003 2.694 1.461 0 477 1 i10 2.468 0.605 3.067 3.209 3 396 2 203 -0.003 2.694 1 467 0 477 1 116 2.470 0.605 3.072 3.208 3 414 2 209 -0.003 2 694 1 487 0 475 1 136 2.476 0.605 3.088 3.204 3 433 2 217 -0 002 2 694 1 507 0 472 1 159 2.484 0.605 3.102 3.204 3 447 2 226 -0 002 2 694 1 529 0 469 1 185 2.496 0.605 3.115 3.206 3 238 -0 0O2 694 1 553 0 464 1 213 2 514 0.605 3.121 3.214 3.456 2 522 0.605 3.125 3.218 3.461 2 244 -0 002 694 1 567 0 461 1 224 2 240 2 534 0 605 3.131 3.223 3.468 2 254 -0 694 1 587 0 457 1 548 0 605 3.136 3.229 3.474 2 264 -0 001 694 1 606 0 453 1 255 2 558 0 605 3.139 3.236 3.479 2.273 -0 001 694 1 624 0.450 1 268 2 281 2 573 0 605 3.141 3.245 3.482 2.285 -0 694 1 642 0.446 1 694 1.664 0.441 1 293 2 591 0 605 3.145 3.260 3.487 2.302 -0 629 0 605 3.132 3.298 3.472 2.329 0 000 694 1.684 0.431 1.305 2 710 0 605 3.100 3.376 3.443 2.389 0.000 694 1.736 0.410 1.312 2 605 3.112 3.505 3.468 2.516 -0.002 694 1.853 0.384 1.317 2 827 0 994 0 605 3.107 3.703 3.471 2.683 -0.003 694 1.962 0.351 1.321 2 605 3.010 4.044 3.370 2.908 -0.009 694 2.039 0.303 1.325 3 297 0 2.694 1.177 0.467 1.097 2 505 0.660 2.816 3.772 3.111 2.494 0.004 2.694 1.189 0.467 1.106 2.512 0.660 2 827 3.758 3.123 2.491 0.004 2.694 1.245 0.463 1.131 2.524 0.660 2 867 3.692 3.171 2.471 0.005 2.694 1.314 0.458 1.160 2.543 0.660 2 912 3.616 3.225 2.448 0.005 2.694 1.391 0.451 1.189 2.567 0.660 2 956 3.548 3.276 2.427 0.005 2.694 1.424 0.447 1.201 2.579 0.660 2 971 3.525 3.295 2.422 0.005 2.694 1.463 0.443 1.217 2.595 0.660 2 988 3.503 3.316 2.418 0.005 Fixed Speed Performance Data 2.694 1.483 0.439 1.231 2.609 0.660 2 992 3.508 3.320 2 427 0.006 2.694 1.499 0.435 1.243 2.622 0.660 2 993 3.516 3.322 2 437 0.006 2.694 1 521 0.430 1 256 2.639 0.660 2 996 3.520 3.326 2 445 0.006 2.694 1 550 0 424 1 268 2.659 0.660 3 000 3.521 3.332 2 452 0.006 2 694 1 584 0 418 1 280 2.683 0.660 3 004 3.522 3.337 2 461 0.006 2 694 1 620 0 411 1 291 2.713 0.660 3 005 3.528 3.340 2 473 0.006 2 694 1 661 0 401 1 302 2.754 0.660 3 002 3.549 3.338 2.495 0.006 2 694 1 691 0 385 1 310 2.825 0.660 2.972 3 622 3.305 2.544 0.006 2 694 1 737 0 361 1 315 2.947 0.660 2.912 3 745 3.244 2.624 0.004 2 694 1 877 0 328 1 321 3.139 0.660 2.873 3 879 3.209 2.738 0.001 2 694 2 217 0 269 1 323 3 595 0.660 2.901 4 381 3.248 3.204 -0.005 334 4.010 2.091 -0.013 240 2 616 0.440 3.614 3 3 233 1 313 0 517 1 335 4.011 2.093 -0.013 617 0.440 3.616 3 3 233 1.315 0 516 1 243 2 351 4.016 2.104 -0.013 261 2 638 0.440 3.620 3 3 233 1.328 0 509 1 676 0.440 3.616 3 388 4.014 2.132 -0.014 276 2 3 233 1.351 0 497 1 464 3.998 2.190 -0.015 288 2 748 0.440 3.590 3 3.233 1.390 0.476 1 621 3.917 2.273 -0.015 292 2 894 0.440 3.503 3 3.233 1.424 0.439 1 096 3.624 2.374 -0.016 231 0.440 3.266 4 3.233 1.319 0.371 1 282 3 404 4 012 2.298 -0.013 647 0.495 3.613 3 3.233 1.500 0.509 1.223 2 648 0.495 3.620 3 399 4 020 2.295 -0.013 3.233 1.503 0.508 1.234 2 395 4 033 2.289 -0.013 653 0.495 3.632 3 3.233 1.506 0.507 1.255 2 399 4 044 2.289 -0.012 663 0.495 3.641 3 3.233 1.510 0.503 1.277 2 686 0.495 3.643 3.416 4 046 2.297 -0 012 3.233 1.519 0.496 1.299 2 739 0 495 3.625 3.467 4 031 2.327 -0 013 3.233 1.541 0.480 1.317 2 695 0 550 3.547 3.490 3.940 2 445 -0 010 3.233 1.634 0.494 1.202 2 445 -0 010 550 3.557 3.488 3.952 2 3.233 1.641 0.493 1.216 2.699 0 550 3.574 3.487 3.971 2 447 -0 010 3.233 1.652 0.491 1.237 2.706 0 449 -0 009 550 3.593 3.487 3.993 2 3.233 1.663 0.488 1.260 2.715 0 550 3.611 3.488 4.014 2 451 -0 009 3.233 1.676 0.485 1.287 2.726 0 459 -0 009 550 3.619 3.503 4.025 2 3.233 1.685 0.479 1.315 2.748 0 466 -0 008 550 3.617 3.518 4.022 2 3.233 1.689 0.475 1.325 2.764 0 550 3 601 3.559 4.007 2 487 -0 008 3.233 1.697 0.464 1.337 2.806 0 548 -0 010 550 3 564 3.652 3.977 2 3.233 1.726 0.443 1.342 2.890 0 614 -0.012 550 3 530 3.747 3.948 2 3.233 1.759 0.423 1.346 2.976 0 694 -0.014 479 3.870 3.904 2 3.233 1 792 0 400 1.351 3.087 0.550 3 790 -0.016 412 4.023 3.840 2 3.233 1 827 0 374 1.354 3.229 0.550 3 335 4.187 3.763 2.884 -0.018 351 1.357 3.378 0.550 3 3.233 1 846 0 331 3 542 3.703 2.423 -0.008 479 1.175 2.748 0.605 3 3.233 1 573 0 333 3 542 3.705 2.424 -0.008 479 1 178 2.750 0.605 3 575 0 3.233 1 343 3 542 3.717 2.428 -0.008 477 1 196 2.756 0.605 3 3.233 1 588 0 541 3.729 2.433 -0.008 353 3 603 0 475 1 218 2.765 0.605 3 3 233 1 363 3 543 3.741 2.440 -0.008 472 1 243 2.777 0.605 3 3 233 1 621 0 374 3 548 3.756 2.452 -0.007 468 1 271 2 794 0.605 3 3 233 1 645 0 551 3.761 2.457 -0.007 801 0.605 3.378 3 656 0.466 1 283 2 3 233 1 556 3.771 2.467 -0.007 298 2 812 0.605 3.386 3 3 233 1 673 0.463 1 564 3.787 2.482 -0.007 823 0.605 3.399 3 313 2 3 233 1.694 0.460 1 575 3.807 2.501 -0.006 326 2 834 0.605 3.416 3 3 233 1.717 0.457 1 592 3.826 2.524 -0.006 850 0.605 3.433 3 3.233 1.741 0.454 1.338 2 628 3.840 2.560 -0.005 881 0 605 3.445 3 3.233 1.770 0.446 1.348 2 605 3.450 3.713 3 852 2.635 -0.005 952 0 3.233 1.820 0.430 1.355 2 605 3.442 3.839 3 852 2.739 -0 007 3.233 1.880 0.408 1.360 3.058 0 824 2.868 -0 009 605 3.409 4.016 3 3.233 1.936 0.379 1.365 3.210 0 741 3.040 -0 014 605 3.323 4.284 3 3.233 1.988 0.341 1.370 3.449 0 660 3.222 3.641 3 592 2.467 -0 002 3.233 1.553 0.463 1.150 2.816 0 608 2 474 -0 002 660 3.236 3.641 3 3.233 1.567 0.461 1.165 2.822 0 660 3.257 3.640 3 631 2 485 -0 002 3.233 1.589 0.460 1.186 2.830 0 660 3.278 3.643 3 656 2 500 -0 002 3.233 1.616 0.457 1.211 2.842 0 520 -0.002 3.233 1.648 0.453 1.237 2.859 0.660 3.299 3.651 3.682 2 529 -0.002 3.233 1.661 0 450 1.248 2.868 0.660 3 305 3.656 3.689 2 314 3.664 3.699 2 541 -0.002 447 1.263 2.881 0.660 3 3.233 1 679 0 316 3.673 3.703 2.551 -0.002 444 1.277 2.894 0.660 3 693 0 3.233 1 317 3.681 3.705 2.560 -0.002 441 1 289 2.907 0.660 3 3 233 1 705 0 318 3 692 3.708 2.572 -0.001 719 0 438 1 301 2.921 0.660 3 3 233 1 320 3 704 3.709 2.585 -0.001 434 1 314 2.937 0.660 3 3 233 1 735 0 320 3 719 3.711 2.600 -0.001 430 1 326 2.955 0.660 3 3 233 1 752 0 320 3 740 3.710 2.620 -0.001 425 1 339 2.978 0.660 3 771 0 3 233 1 418 1 349 3.015 0.660 3.313 3 777 3.702 2.649 -0.001 3 233 1 791 0 358 3.088 0.660 3.276 3 853 3.661 2.697 -0.002 3 233 1.811 0.403 1 365 3.215 0.660 3.217 3 987 3.602 2.786 -0.004 3.233 1.852 0.379 1 Fixed SpeedPerformanceData 3.233 2.009 0.344 1.370 3.442 0.660 3.216 4.255 3.617 3.034 -0.007 3.233 2.148 0.302 1.374 3.776 0.660 3.189 4.655 3.594 3.353 -0.011 N

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Form Approved REPORT DOCUMENTATION PAGE OMB No 0704-0_ Public reporting burden forthiscolleclion 04information is _tlmatod to average 1 hourpetrespons.e. Including thetimeforreviewing insm,mtions Mmrchlng existing datasource, gathering andmaJntaln|ng the da_a needed, andcompl_ing ariarev.k)wlng the colisctk_, of Information. Sendcomments regarding thisburden estlrnale or any othwaspect of this collection of informalion. Including suggestions forreduc0ng thisburoen, toWashington Heaoquarteri Sewk:es, Dlrectorato forInformation Operations andReports, 1215Jefferson Davis Highway, Sutte1204,Arllngton, VA 22202-4302, andto theOffioe of Management andBudge(, Paperwork Reduction Pro_ (0704-0188), Washington. DC 20503.

3. REPORT TYPE AND DATES COVERED 1. AGENCY USE ONLY (Leave blank) 2. REPORT DATE June 1996 Final Contractor Report 4. TITLE AND SUBTITLE 5. FUNDING NUMBERS Wave Rotor Demonstrator Engine Assessment WU-505--62-10 C-NAS3-25950 s. AUTHOR(S) Philip H. Snyder 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT NUMBER Allison Engine Company, Inc.

E--10307 P.O. Box 420 Indianapolis, Indiana 10. SPONSORING/MONITORING i 9. SPONSORING/MONITORING AGENCY NAME(S) ANDADDRESS{ES) AGENCY REPORT NUMBER National Aeronautics and Space Administration lewis Research Center NASA CR-198496 Cleveland, Ohio 44135-3191 11. SUPPLEMENTARY NOTES Project Manager, Gary J. Skoch, Vehicle Technology Center, U.S. Army Research Laboratory, NASA lewis Research Center, organization code 0300, (216) 433-3396.

12a. DISTRIBUTION/AVAILABILITY STATEMENT 12b. DISTRIBUTION CODE Unclassified -Unlimited Subject Category 07 This publication is available from the NASA Center for AeroSpace Information, (301) 621-0390 13. ABSTRACT (Maximum 200 words) The objective of the program was to determine a wave rotor demonstrator engine concept using the Allison 250 series engine. The results of the NASA LeRC wave rotor effort were used as a basis for the wave rotor design. A wave rotor topped gas turbine engine was identified which incorporates five basic requirements of a successful demonstrator engine. Predicted performance maps of the wave rotor cycle were used along with maps of existing gas turbine hard- ware in a design point study. The effects of wave rotor topping on the engine cycle and the subsequent need to rematch compressor and turbine sections in the topped engine were addressed. Comparison of performance of the resulting engine is made on the basis of wave rotor topped engine versus an appropriate baseline engine using common shaft compressor hardware. The topped engine design clearly demonstrates an impressive improvement in shaft horsepower (+11.4%) and SFC (-22%). Off design part power engine performance for the wave rotor topped engine was similarly improved including that at engine idle conditions. Operation of the engine at off design was closely examined with wave rotor operation at less than design burner outlet temperatures and rotor speeds. Challenges identified in the development of a demonstrator engine are discussed. A preliminary design was made of the demonstrator engine including wave rotor to engine transition ducts. Program cost and schedule for a wave rotor demonstrator engine fabrication and test program were developed.

14. SUBJECT TERMS 15. NUMBER OF PAGES 16. PRICE CODE Wave rotor; Compressor;, Turbine A04 17. SECURITY CLASSIFICATION 18. SECURITY CLASSIFICATION 19. SECURITY CLASSIFICATION 20. LIMITATION OF ABSTRACT OF ABSTRACT OF REPORT OFT HIS PAGE Unclassified Unclassified Unclassified NSN 7540-01-280-5500 Standard Form 298 (Rev. 2-89) Prescribedby ANSI Std. Z39-18 298-102

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NASA Contractor Report 198496