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NASA Technical Memm-
i
ndum 82608
r
Turbine Bypass Engine — A New
Supersonic Cruise Propulsion ConCe x
p
N61-16145 6hGlbk: A JUREINY BIPASi (NASA-TO-E2tOb) CLbc k I I:hGISE Pb^EULSIGR 11c: NEW SUPLLS""- Al,^/MF AG 1 C1dS ^"`LL UD 15 P He (NASA)
^.i/J7 16674
^^ ,
Leo C. Franciscus
Lewis Research Center
Cleveland, Ohio
1 rV S,
Prepared for the
Seventeenth Joint Propulsion Conference
cosponsored by the AIAA, SAE, and ASME?
Colorado Springs, Colorado, July 27
-
29, 1981
TURBINE BYPASS ENGINE - A NEW SUPERSONIC CRUISE PROPULSION CONCEPT by Leo C. Franciscus National Aeronautics and Space Administration Lewis Research Center Cleveland, Ohio Abstract performance and increase the transonic thrust CAP4- to bilities of the turbojet with more simplicity than the variable geometry turbine, w Engine performance and scission studies were car- Although one and two spool versions of Boeing's Hod out for a single-spool Turbine Bypass Engine turbine bypass engine (TBE) concept have been pro- (TBE) concept. Comparisons were made b*tween the posed, recent studies of the ongine have indicated single -spool turbojet, and the that the single spool version would be a more simple TBE, a conventional engine and would have about the same performance Pratt & Whitney Variable Stream Control Engine (VSCE), The airplane arsomed for characteristics as a two spool version. NASA-Lewis the study was a Mach 2.32 commercial supersonic transport. The nom- has contracted with Pratt & Whitney to study the single spool TBE. In -house studies of this concept inal mission was a 40419 n.mi. total range with a 300 have also been carried out at NASA-Lewis. in these n.mi. subsonic cruise leg. The figure of merit was the minimum takeoff gross weight for the mission. studies, the TBE, a variable- geometry-turbine turbo- jet and the Pratt tt Whitney variable-stream-control Comparisons of the three engines were also made for (VSCE) turbofan were compared. Engine performance the 4000 n.mi. total range with longer subsonic cruise legs. and mission studies were performed for the three en- gine concepts. The potential of the engines was as- Nomenclature sessed in terms of the performance of a future com- mercial supersonic transport. This paper provides the results of these studies.
BPA E,vpass ratio CET cxmbustor exit temperature Method of Analysis lift coefficient F R fap pressure ratio The analytical procedures followed for this OPR cycle pressure ratio study are summarized in figure 1. Aerodynamic and Po free stream static pressure weight data far the airplane were obtained from rep- SFC specific fuel consumption erence 3. in the engine performance and weight cal- S.L.S. sea level static culations, the same technology level assumed for TIT turbine stator inlet temperature was the three engines. The study reflected differences TOGW airplane takeoff gross weight in pod drag and weight of the engines considered.
W f/6 corrected gas flow rate The airframe and the engine data were then used in flight performance calculations to determine the Subscripts: takeoff gross weight as a function of engine sea 0 free stream level static design airflow for a fixed range and payload.
3 compressor exit turbine stator entrance Mission Introduction The baseline mission considered in this study The relative simplicity, compactness and good was a Mach 2.32 supersonic cruise with a 300 n.mi.
(556 km) subsonic cruise leg for a standard lay + supersonic cruise performance of the Turbojet makes 14.4 * F (8 Q. The total mission range was fixed it an attractive candidate for a supersonic airplane at 4000 n.mi. (7406 km) but variations in the sub- propulsion system. The Olympus engine on the Con- sonic cruise range were assumed to show the effects corde supersonic transport is a two-spool turbojet.
of the subson i c cruise performance of the engines.
In the first UniteJ States SST program,, the General Electric i3E 4 turbojet was selected. However, on The mission profile is illustrated in figure 2. A NASA's stpersonic cruise research (SCR) program constant 213 n.mi. (394 km) descent from the final which began in 1972, alternatives were sought be- cruise altitude at an estimated flight-idle fuel cause the turbojet was considered to have a diffi- flow was assumed for all cases. The total of 4000 n.mi. (7408 km) was the total of climb/acceleration, cult noise problem and unacceptable subsonic cruise performance. Hence, SCR emphasis has been on new sutsonic and supersonic cruise and letdown ranges.
cycle concepts that are inherently quieter and have A part of the fuel load available was held in reserve for the following requirements: better low-speed performance.
(1) Retain an enroute contingency fuel allow- However, there is recent renewed interest in the ance equal to 5 percent of the mission fuel..
turbojet in the SCR program. The latest develop- (2) Provide for a 260 n,mi. (482 km) diversion ments in mechanical noise suppressors (ref. 1) are to an alternate airport at Mach 0.9 at an Also, a promising thermal acoustic encouraging.
optimum Brequet cruise altitude.
shield (TAS) noise reduction scheme (ref. 2) has (3) Provide for a 30-minute hold at Mach 0.45 been suggested and is currently being investigated.
at an altitude of 15 000 feet (4572 m).
Varia ble geometry turbines would be a means of improving the turbojet subsonic cruise performance Airframe but are undesirable due to their complexity. How- ever, Boeing has reported an innovative turbine by- The weight and aerodynamics for the basiline p ass concert that may improve the subsonic cruise airplane used in this study were for the Langlay-LT1 low temperature design and lower thrust. The small- er turbine could not be operated at the same high arrow-wing airplane defined in reference 3. The ma•.
turbine inlet temperature as the largeAy jor of the airp lane are turbine
characteristics summarized
without surging the compressor . the lini ations an in table 1.
the operating turbine inlet temperatures set by the in figure 1. A
compressor/turbine design are shown
Propulsion System minimum surge margin of 20 percent and a maximum op- erating turbine inlet temperature of 3160 R (1766 K)
The W nstalled engine performance was first
without inlet are assumed. The large AN turbojet is matched for calculates, and nacelle drags using the 3160 R (1756 K). Thelarge Au turbojet can to NASA-NAVY Engine Program, reference 4, The engine
maximum turbine inlet temperature for
operated near
component aerodynamic characteristics, efficiencies
almost all conditions. The small AN turbojet must and cooling requirements used in the program were be operated at much lower temperatures to ma ntain compatible with the Pratt it Whitney early to mid- 1990's technology level. however, a three-count ef- the 20 percent compressor surge margin. The accel- ficiency penalty was assumed for the variable area eration thrust and SFC's of the two engines are com- turbines compared to the fixed -area turbines. pared in figure 6. The large turbojet would The inlet sizes were determined by the super- have 60 percent more transonic thrust than the small sonic cruise airflow. Inlet/engine airflow matching AN turbojet. It shall W not4d, however, that the studies were conducted. The engine airflows were higher thrust of the large AN turbojet it at the scheduitu to match the Boeit .!j inlet. Cowl pressure expense of higher SFC's.
drag was not included since dimensional data A comparison of the subsonic cruise performance for the TBE are not well defined. Bypass, bleed and of the two engines is shown in figure 7. Although spillage drags were determined for the inlet per- the high thrust of the large ANturbojet is bone- formance. engine must be ficial for acceleration, the substan- Nozzle performance includes internal losses and tially throttled back for cruise. In this case, the boattail drag. An internal nozzle velocity coeffi- 20 engine is throttled back along a percent compres-
cient of 0.985 was assumed for all cases. Boattail
sor surge margin as shown in figure 3. This reduces drag was calculated with data from reference S.
ongine airflow resulting in lower propulsive effi- The installed engine performance is the unin- ciency. Also, the inlet air supply remains fixed so stalled performance adjusted for the inlet, nozzle that inlet air must be bypassed overboard as the en- and nacelle drags.
Sine air demand reduces resulting in large bypass The installed propulsion system weightincludes dreg. As seen in figure 7, the large AN turbojet the engine plus nozzle/reverser, inlet and nacelle. is oeavily penalized at the subsonic cruise operat- The TBE engine/nozzle/reverser weight was obtained ing point. The small AN turbojet is operating from preliminary estimates from Pratt a Whitney. clraer to its maximum thrust and has an SFC 22 per- cent lower than the large AN The turbojet/nozzle/reverser weight was assumed to turbojet.
be the same as the TOE. The VSCE engine/nozzle/ reverser weight was obtained from reference 6. The Turbine Bypass Engine and the Variable Turbine Weight estimates for the Boeing inlet and the na- Area urboiet cel/e were made with data from reference 7.
The major characteristics of the three engines One means of removing the restrictions assoaia are given in table It. ted with the choked turbine is with a variable area turbine (VAT). With the ability to vary the turbine Results Mid Discussion area, the turbine corrected flow can vary, thus per- mitting wider excursions in the operating turbine Sing le-S pool fixed-Turbine-Area Turbojets temperature. For a given flight condition inlet this allows the compressor to operate at nearly a Figure 3 depicts the matching of a compressor fixed point for wide variations in throttle. This and turbine for a single spool turbojet. The tur- avoids the port power performance penalties of the bine is choked for nearly all operating conditions fixed turbine (fig. 7). Figure 8 shows typical op- indicated by the constant valve of turbine corrected erating characteristics of the variable area turbine airflow W4 (VAT) analyzed in this study. At Nach 0.9, the tur- %/0-4/64. For variations in turbine inlet temperature, the compressor will operate at bine area varies by 30 percent between low throttle pressure ratios and airflows to satisfy the constant cruise and maximum thrust acceleration. The com- value of turbine corrected airflow. For a pre-. pressor operating points for these two conditions scribed compressor airflow, the compressor operates are seen to be very close, at increasiq pressure ratios with increasing tur- The objective of the turbine bypass concept is bine inlettemperatures. Tne compressor surge mar- very similar to that of the variable area turbine.
gin, (usually about 20 percent) places a constraint However, instead of varying the turbine -area.the on the upper limit of turbine inlet temperature. turbine airflow is varied without changing the com- There are, of course, other constraints such as ma- pressor airflow.
During his propulsion studies at Boeing, Garry terials, coolino, etc. Decreasing the turbine inlet Klees found that regulating the airflow into the temperature at a fixed compressor airflow causes de- burner and turbine provided a convenient means of creasing pressure ratios. Lower limits on the tur- achieving a constant corrected airflow into a fixed bine 'inlet temperatures would have to be evaluated 9eometry turbine with excursions in turbine inlet in terms of low compressor efficiencies or limits on nozzle area variations. temperature. Figure 9 shows a schematic of this single :.pool engine. In this scheme, Selecting a particular compressor/turbine combi- concept for a nation places limits on the turbine inlet tempera- the compressor is matched with a small AN tur- ture excursion a turbojet can achieve. Matching com- a bine. A provision is made for bypassing some compressor to a large annulus area,, turne pressor discharge air around the burner and turbine (fig; 4) reflects a high temperature designand high and into the nozzle. As shown in the figure, the thrust. For the same engine airflow, matching the turbine inlet temperature for zero bypass is 1900 R same compressor to a small AN turbine reflects a (1055 K). As the turbine inlet temperature is in-
r
creased the bypass airflow, WOP, is increased. The turbojet. The cruise SFCof the VSCE is about 9 actual turkiine airflow, percent higher than those of the other two engines, W4, is reduced to achieve the constunt turbine corrected flow & ibmistc (37.2
t
kg/sec). Ihis enables a wall AR turbojet to be Mission Studies operated at the maximum turbine inlet temperature of 3160 R (1756 K) by bypassing some fo the compressor As shown in the previous section, the TBE and discharge air. Figure 10 shows the variation opt the the VAT turbojet have better acceleration and super- compressor discharge air with Vlach number for a con - sonic cruise performance than the VSCE. As seen in stant turbine inlet temperature of 3160 R (1156 K) table 11, however, the VSCE weighs less than the and 20 percent compressor surge margin. other two engines for the some engine size (air- Since the cun+pressor discharge total pressure is flow). The VSCE engines can be larger than the other two engines without incurring as much weight much higher than that of the nozzle, the bypass air may have to be throttledto the nozzle total pres- penalty. This reducesacceleration time and lessens the penalties incurred by the high transonic/super- sure to prevent possible undesirable aerodynamic ef- 16 shows range ver- sonic SFC's of the VSCE. Figure fects at the turbine exit. In this study, throt- sus engine site for the three en ines. The engine tling of the bypass air represents total pressure size for maximum range for the VSCE is 120 lb/sec losses of the bypass air as high as 80 percent.
(327 kg/sec); 30 percent larger than the best engine Figure 11 shows the improvements in the turbojet sizes for the TOR and VAT turbojet. The better subsonic cruise performance with the TBE concept and the VAT. Compared to th` large41 fixed-area-tur- SFC's of the TOE and VAT turbojet (compares to the Y SCE) result in 4010 to $00 n.mi. (141 to 1 346 km) bine turbojet, the TB: and the VAT improve the more range for the best engine sizes. figure 17 cruise SFC by 20 percent. The cruise SFC's of the compares the mission performance of the three en- TBE and the VAT are about the same. At maximum power, the VAT has the highest thrust but also the gines in terms of takeoff gross weight for a 4000 n.mi. mission range.The minimum TOGW of the TBE is highest SFC. The maximum thrust of the fixed area 8 percent lower than that of the VSCE.
turbojet is about 6 percent lower than the VAT tur- bojet since it cannot be operated at maximum turbine Figure 18 shows the ef f ect of longer subsonic inlet temperature without sueging the compressor cruise range on total range. The reference point is ( fi g . the 4000 n.mi. (7408 km) total range with 300 n.mi.
BK is (^S6), emperatu 9 he is the re, 3160 8 VAT (556 km) subsonic cruis(: leg and the takeoff gross turbojet, its maximum thrust is 16 percent lower be- weights are the minimum values from figure 11. The cause 22 percent of the engine air is bypassed subsonic cruise range is seen to have only a small around the burner and turbine. This also reduces effect on total range. This is especially true for fuel flow resulting in a lower SFC.
subsonic ( ,ise ranges less than 1000 n.mi, (1851 km) usuall considered for an SST-mission. It En ine Performance Coi,.parisons - TBE, VAT Turbojet.
should be pointed out that this result stems from P & WA ME the good subsonic cruise SFC's of all three of the engines compared to a fixed turbine turbojet.
The performance of the TBE and the VAT turbojet are compared to Pratt & Whitney's VSCE which is a Conc)udina Remarks moderate bypass ratio duct burning turbofan. Be- cause it is a bypass engine it has the potential for A study was made to compare the mission perform- good subsonic cruise performance (maximum dry power ances of the turbine bypass engine, TOE, to the mis- cruise) and quiet takeoff. On the other han g , duct sion performance of a variable area turbine, VAT, burning, leading to higher SFC's, is required for turbojet and the P & WA variable stream control en- transonic and supersonic operation.
gine, VSCE. The study included engine performance A comparison of the performance of the TBE, VAT analysis and mission performance. The minimum take- turbojet and the P & WA VSCE at Mach 0.9 is shown in off gross weight (TOGW) of a commercial supersonic figure 12. At the cruise operating points, the SFC transport for a 4000 n.mi. (7408 km) range was used of the VSCE is about 6 percent better than those of as the figure of merit. The maximum rana for a the TBE and VAT turbojet. however, the high thrust fixed TOGW of 762 000 pounds (345 950 kg? was also performance of the VSCE is much poorer than the used. The effect of subsonic cruise range was in- other two engines since duct burning is required. vestigated.
This characteristic is also shown in figures 13 and The results of the study show that the mission 14 (duct burner fuel/air ratios were reduced with performance of the TBE and a VAT turbojet are about larger engine sizes). In figure 13, the transonic the same. The TOE TOGW is about 8 percent lower thrust of the VSCE is seen to be 15 to 25 percent than that of the VSCE for the 4000 n.mi. range. The lower than the TBE and 30 to 40 percent lower than maximum range of the TBE is 10 percent higher than the maximum range of the VSCE for the 762 000 puunds that of the VAT turbojet. At supersonic accelera- (345 950 kg) airplane. The mission performance of tion, the thrust of the TBE and VSCE are compar- the TBE and VAT-turbojet are superior to the VSCE able. The VAT turbojet has the best acceleration thrust of the three engines. In figure 14, the VSCE because thoy have significantly lower SFC's at tran- sonic/supersonic acceleration and supersonic exhibits the best subsonic acceleration SEC's. Dur- cruise. The length of the subsonic cruise leg has a ing transonic and supersonic acceleration, the SEC's small effect on mission range for all three en- of the VSCE are about 20 percent higher than the gines. This results from the efficient low thrust other two engines.
cycle characteristics of the TBE, VAT turbojet and Since most of the acceleration fuel of the SST is consumed during transonic/supersonic accelera- VSCE. Also, the high port-power airflow character- istics of these engines reduces the inlet bypass tion, the VSCE would benefit from larger engine drag, which comprises a major part of the throttle- sizes than the TBE or VAT turbojet to reduce accel- back drag at subsonic cruise.
eration time and fuel.
It should be stressed that the mechanical and Figure 1.5 shows a comparison of the supersonic cycle features of the VSCE have been under study by cruise performance of the three engines. The SFC's of the TOE are somewhat lower than those of the VAT Pratt do Whitney for several years. The same in- WO
depth studies of the TOE have yet to be 6. Howlett, R.A, and iiunt, R.R., "VSCE TechnoI
WhMy
D o efinition Study, Final Rsprt," Pratt a
plished. Fined comparisons of the two concepts Aircraft, East Hartford, CT, ft%- 5634041, Aug.
would have to await completion of these studies. It
these engines are com- 1974. (NASA CR-159730)
should also be stre.sed that 7. Howlett, R.A., "Advanced Supersonic Propulsion
pared on a mission performance basis only, Since
Phase 1," Pratt i Whitney Aircraft, East
the VSCE would be inherently quieter than an unsup- Study,
Hartford CT, PW1-5312, Sop. 1975. (NASA
pressed TOE at takeoff, noise constraints may have a
4)
CR-1349i
more significant impact on the TOE than on the VSCE.
The novel feature of the TOE is the libility to
:rate at low part power with high propulsive effi- Mop MAJOR AIRPLANE CHARACTERISTICS TABLE /, -
ocy. This feature should be eiiploited for other
fighter subsonic
Characteristic
Value
#Adl supersonic u flight requirements, cruise missiles
and turbo:shafts for helicopters.
Takeoff grossweight: of
762 000
References
kg 345 637 16 Fitzsimmons, R.O., McKinnon, R.A., Johnson, E.S.,
Numiber of passengers
and Brooks, J. R., "Flight 0V Wind Tunnel rest
Results of a Mechanical Jet Noise Suppressor Pay Nozzle," AIAA Paper 80-0165, Jan. 1980.
l oad" 61 02e
2. Cowan, S.J. and Crouch, R.W., "Transmissiar, of
kg 27 682 Sound Through a Two-Dimensional Shieldir.g
Jet,"
AIM Paper 73-1002, Oct. 197J.
Reference wing area:
3. "Advanced Supersonic Technology Concept - Study
ft 9 969
Reference Characteristics," LTV Aerospace Corp.,
m
Hampton, VA, Dec. 1973. (NASA CR-132374)
4. Fishbach, L.H. and Caddy, M.J., "NNEP - The
Operating empty weight less
Navy-NASA Engine Program," NASA TM X-71857, 1975.
Propulsion weight:
S. Kowa] SkisE.J., "A Computer Code for Estimating
Ibm
259 913
Installed Performance of Aircraft Gas Turbine
kg 117 697
Engines. Vol. 3: Library of Maps," Boeing Co., Seattle, WA, 0180-&5481-3-VOL-3, Dec. 1979.
Lift-off CZ
0.55
(NASA CR-159693)
TABLE 11. - ENGINE CHARACTERISTICS
TBE VAT P & WA
turbojet VSCE
._ Engine cycle description ► .g/!ec) 750 (341) 750 (341) 750 (341) W %1- 9/a, 1bm/sec ( 3.3
FPR----- ------ ----------
18 15 OPR 18 ------ ---- -- 1.3 SPR CET, R (K) 3160 (1756 3160 (1756) 3160 1756 Max *3140 (1756 *2800 (1556) 2500 S.L.S.
Max OBT, R (K) ------------- ------------- 3060 (1700)
Engine weight Engine + nozzle/reverser, 13 550 (6152) 13 550 (6152) 11 500 5221 lbm (kg) 12270) Inlet + Nacelle 5 000 (2770)5 000 (2270) 5 000 16 500 (7491) Total, lbm (kg) IS 550 (8422) 18 550 (8422) AIRFRAME STRUCTURE AND AERO DEFINED 1111t' LgwY-LTV ti Figure 1, - Calculallcn flow chart.
r OPTIMIZE: INITIAL i CRUISE ALTITUDE t MACH 2.32 CRUISE rOPTIMIZE INITIAL I CRUISE ALTITUDE CL91A@ ► ACCELERATION ALTITUDE DESCENT MACH 0. 9 CRUISE CLIMB LAND WITH ACCELERATIONRECOMMENDED RESERVES------ RANGE Figure w - Reference misslon, std. + 14.4 0 F I+ S0 Cl day.
2 SURD!
MARGIN—, %%%k INCREASE TIT rr SURGE ^„^ d CHOKED
w
W146 PRESSURE RATIO, Ps P5
CORRECTED AIRFLOW, b) Turbine (a) Compressor, ( Figure I - Matching char a cteristics of a single spool turbojet.
TURBINE r.COMPRESSOR BURNER 'AN (a) Single spool turbojet, large AN
C
WJ4164 13iS aw '0dasnl#Nl • M CJ ET N i71 ^ V^ Ci #Qlt jutw 9l loiS
Z U 'nd115 na N l
V
UN
e a ^N 41 ^ d LB
P"
Jun d ' alp '38niVa3dW31331NI 3NI8an1 NIOUVW
c
30anS a0SS3adW03+'$ I So '38MV83dW31171NI 3NI8an1 r a 1.J ,13 t. Z 1, l 1`0 ,10 .9 0 40 60 fl0 t00 120 THRUST, 1000 N i 1 1 1
10 000 15 ODD 20 ODD 25 Wo
THRUST., Ibf
Figure 7, - Effect of turbine area
on engine performance at MACH
a 9; single spool turbojet; see level static airflow. 750 lbmtsec
1341 kgl secL
TRANSONIC ACCELERATION (MACH Q 9)-N TRANSONIC -2n SURGE VARIATION ACCELERATION % SUBSONIC ^^^ MARGIN {MACH Q 9!; CRUISE (MACH
0 9!—
W
..,p-
/ UPERSONi
.f^UBSONIC
$^ '-SUPERSONIC
CRUISE
CRUISE
iMACH O: 9)
CORRECTED AIRFLOW
PRESSURE RATIO
(a) Compressor.
Ib! Variable arse turbine.
Figure 8. - Op rating characteristics of a single spool turbojet with a vari-
able area turbine (VAT).
T`
260.
.c
IW^Ibil.12lbmisec
r 90
(N.2 WW)
BYPASS-,^, rSMAlI AN
wo
c
TURBINE BYPASS ENGINE
20 /•`
IL 10
Q000 1200 1100 1600 1800 TURBINE INLET TEMPERATURE, OK
1800 2000 2200 241!i! 2600 2800 3000 3200
TURBINE INLET TEMPERATURE, OR Figure 9 - Varl itisn of bypass air and turbine Inlet air with tur- bine inlet temperature; MACH a 90.
4 NAXI W DAY THRUST Ls— O CRUISE .13 L2 TURBOJET - LAROE A N , FIRED AREA 12 I2 REG(RA E0 '' 1.1 ,11 .•''^ TOE IYPASS.%,,,,
AT TURBOJET TURBOJET
i.0.10
^ -TOE - WAti. AN
'* L
. OI
50 60 70 10 90 100 110 12
THRUST, 1000N ODD 2 5000
1000 10 000 is Qm 20
THRUST, ibe prt power chara is- Figure 11. - CoMrison of maximum pow and tks a h YOE, x variable area turbine turboles ara^ a fixed area turn" 019 it f1 O00 h so level sink tuyl*,1 is MACH R 9s altitude, 31 alrlww, 110 lbmisec 1311 kgissc).
O MA XIMUM DRY THRUST 1.3 .13
1.2
.12
TBE^
%
1.0 -'t-VAT TURBOJET
.9 - `ASCE 0 40 80 100 120 140 20 60 THRUST, 1000 N i t I # 30 000 0 10000 20 000 THRUST, IN Figure 12. - Comparison of subsonic cruise performance of the TBE.
turbojet and the p&wA VSCE. MACH Q 9; altitude, 36 089 It.
VAT ill 000 mi, sea level static airflow. 750lbmfsec 1341 kglsecl.
I3i'1 }
^
MACH NINBER Figure 13 = Comparison of the TOE, VAT turbojet and the P&WA VSCE acceleration thrust, us level static airflow, M lbmIssc 1341 kgtssd.
1.6
.16
.15
/ VSCE
r
1'4 .14 .
VAT
TURBOJET- ► ► ''
.^
1.3
' T
TOE'
1.2
.11
1.0
.10
'$
1.0 1.5 2t1^25
°Ba a^
m MACH NUMBER Figure 14. Comparison of TOE. VAT turbojet and the P&WA VSCE acceleration SFC, so level static airflow, 750 lbmisec 1341 kglsecl.
0 MMM UAI DAY THRUST
O CRUISE
.153
f
Z: S
.150
f
^ASCE
1.4 1.145
.1NI VAT TURBOJET .1 IRE •1 --- 600 n0 100 1201 0 THRUST, 1000 N
10 15 20 25 30
THRUST, 1000 M
Figur v 15. • Comperlson of the 18E, VAT turbojet and the P&WA VSCE supersonic cruise performances MACH 2 . 32s altitude,
53 000 ft 116154 A sea level static airflow, 750 Ibintsec
1301 kgsecl,
11500
60001
10300—
9 5 ......,^ TBE 00
VSCE ^—
VAT TUR801E7
I 1 I I l
260 3M 340
ENGINE SEA LEVEL STATIC AIRFLOW.
kgtsec I I I 500 600 700 800
ENGINE SEA LEVEL STATIC
AIRFLOW. ibmtsec
Figure 16. • Mange versus engine size comparison for
the TOE, VAT turbojet, and tho P WA VSCE; MACH
&
2.32 cruises 300 n. mi. 1556 km) subsonic cruise; TOGW 762 000 Ibm 1345 950 kP,, 292 passengers.
+n .1
VSCE -%%
aww'0011W mow
I @ -3W 6S0 VAT TURBOJET TOE
t^3
2 tg
► -
600 7M M
i
ENGINE SEA LEVEL STATIC AIRFLOW, kgistc ►
400 500 600 700 ENGINE SEA LEVEL STATIC AIRFLOW, Ib+nfsec
Figure 17, - Mission performance comparison of the TOE. VAT
mi.
turbojet, and the P&WA VSCE MACH Z 32 cruise. 300 n.
(556 km ► subsonic cruise; 4000 n. mi, 17406 km) total mission
range; payload, 242 passengers.
E 8000 ,-VS CE .E BE-.
000 _^ T 4 -+ VAT INC C S TURB ET--'" 3800 r- ^r` N 1000 2000 3000 4000 5000
SUBSONIC CRUISE RANGE, Km
I ! i
I I
o Soo 1000 1500 2000 two
n, mi.
SUBSONIC CRUISE RANGE, Figure 18. - Effect of subsonic cruise range on total range; MACH 2.32 supersonic cruise; MACH 0. 9 subsonic cruise; X payload, 292 passengers.
s