Document
II N94- 33523
HSCT HIGH-LIFT TECHNOLOGY REQUIREMENTS D.L. Antani J.M. Morgenstern Douglas Aircraft Company McDonnell Douglas Corporation 3855 Lakewood Blvd.
Long Beach, CA 90846 First Annual High-Speed Research Workshop Williamsburg, Virginia May 14-16, 1991 WARNING: INFORMATION SUBJECT TO EXPORT CONTROL LAWS Thisd_umentmayc_ntai_inf_rmati_nsubjectt_the_nternati_na_Tra_icinArmsRe8u_ati_n(_TAR)and_ortheE-r_p_rtAdministra_ tion Regulation (EAR) of 1979 which may rmt be exported, released, or disclosed to foreign natic_als inside or outside the United States without first obtaining an export license A violation of the ITAR or EAR may be subject to a penalty of up to I0 years imprisonment and a fine of $100,000 under 22 U.S.C. 2778 or Section 2410 of the Export Administration Act of 1979. Include this notice with any reproduced portion of this document.
P, REGED|NG PAGF. BLANK NOi- tr|LMED AGENDA The discussion topics are listed in this figure. The high-lift needs and related aerodynamic goals have been established in the recent system studies conducted for NASA. Next follows the status of the related high-lift database and available design and analysis methods. A summary of future high-lift technology requirements is presented followed by concluding remarks.
High-LiftNeeds
• Status
Technology Requirements
Conclusions
Figure l MDC HSCT BASELINE DESIGN AND MISSION REQUIREMENTS Current MDC HSCT baseline design and mission requirements are shown in this figure. There are 300 passengers in a three-class configuration, range is 5,500 nmi with 25-percent subsonic overland. The aircraft is to meet FAA Part 36 Stage 3 noise certification limits. The TOFL requirement is 11,000 ft. Note the significant portion of mission segments (indicated by a heavy llne) where efficient low-speed, high-lift, and subsonic climb and subsonic cruise aerodynamics are required. Efficient subsonic characteristics are also required for all reserve segments to minimize reserve fuel requirements.
Douglas HSCT Baseline Desiqn and Mission
Requirements
NUMBER OF PASSENGERS = 300 (3-CLASS) RANGE = 5,500 N Mi, TOFL = 11,000 FT (STD + 27F) FAR PART 36 STAGE 3 NOISE CERTIFICATION LIMITS MACH 1.6 - MACH 2.4 SUPERSONIC CRUISE-CLIMB _ RESERVES '-._--_-i_ ..-I I I ICONTINGENCY I 14_ K_AS -.-_:."_'-:'_' I 16% BLOCK
MACH 095 SUBSONIC I <_0 A'_A_ I UEL J
CRUISE AT BEST I ' I::IAI'.J_ I = t ' I LI::EI"I') ...... "J' t , I MACH095SUBSONIC j IFR ALTITUDE I CRUISE AT BEST 17 MIN - I ...... 1 IFR ALTITUDE I • _ ' - " I 1 MIN _ I TAKEOFF7 I _ TRANSON,C ACCEL I /GOAROUND B | 30 MIN / |4OO KCAS _ 6 MIN I FOR MISSED | | HOLD I %%"1 J , ! _.x..._,o,c-.-I I ._ .
MIN 1,500FT ,_ 5,500N Mi DESIGN RANGE _----I I CRUISE I Figure 2 REFERENCE NOISE CERTIFICATION POINTS Typical noise certification monitors at sideline, takeoff, and approach are shown in this figure. One of the objectives of the high-lift design Is to improve aerodynamic efficiency so that the noise levels at these points are lowered. Results showing this effect are presented later.
Reference Noise Certification Points where
Efficient High-Lift System is Required
I CUTBACK J (ONE ENGINE OUT OR I
4% GRA=ENT POWER)t__._.___.__
i SIDELINE/TAKEOFF ]
/ 11% .SLOE.L'NE
' 1 1_ ._ (1) I_tOI_ORS l e RAKES RELEASE I .... .... :____=.
4so m'(_,476 FT) RUNWAY -- - --f-_ - -_,__ ._ 2 _ _ 450 m &--_-JL___ J_____* .... , TAKEOFF 1 1 1 1 1 /__2) /- 6,500 m (21,325 F'r) ,p- MONITOR 3 DEG'_ _ JRUNWAY THRESHOLD J j APPRO_ APPROACH _ 394" FT _ I ' MONITOR l,,,/ 50 FT
\- \ "
\
2,000 m (6,562 FT) Figure 3 BALANCED AERODYNAMIC DESIGN To make the HSCT economically viable and environmentally acceptable, the challenge is to design an HSCT wing that optimally balances low-speed, subsonic, and supersonic requirements. The figure shows that there are many low-speed takeoff and approach, and subsonic climb and cruise aerodynamic goals. These goals will have to be met by an optimum wing and high-lift system. The basic supersonic L/D requirements will also have to be met.
Balanced Aerodynamic De-_i.cln is Reauired to
Optimize Low-Speed, Subsonic_ and
Supersonic Performance
ECONOMIC VIABILITY AND ENVIRONMENTAL ACCEPTABILITY L I J'
/\
NASA • DEVELOP TECHNOLOGIES • PROVIDE TEST AND COMPUTING FACIUTIES INDUSTRY INTEGRATE TECHNOLOGIES • REQUIRE HIGH AR, LOW SWEEP WING • REQUIRE LOW AR, HIGH SWEEP WING DESIGN WING AND HIGH-LIFT DEVICES • HIGH C L FOR TOFL INTEGRATE AIRFRAMFJENGINE • HIGH L/D FOR SUPERSONIC CLIMB • HIGH L/D FOR SECOND SEGMENT CLIMB • HIGH L/D SUPERSONIC CRUISE • HIGH L/D FOR SUBSONIC CLIMB • HIGH IJD FOR SUBSONIC CRUISE • HIGH L/D FOR APPROACH • HIGH CL FOR LOW APPROACH SPEED • HIGH L/D FOR RESERVE SEGMENT Figure 4 1771 IMPACT OF HIGH-LIFT TECHNOLOGY The impact of high-lift technology on performance, noise, and stability and control are highlighted in this figure. Note that the high-lift system will have to be integrated with other performance enhancing technologies, e.g., LFC and noise reduction devices (such as mixers/ejectors) as these technologies mature.
Impact of High-Lift Technology
Performanq_ • TOGW, engine size, TOFL, and approach speed are significantly affected by efficient high-lift capability.
• High subsonic L/D reduces fuel burn (.'. weight) in the subsonic climb and cruise mode.
Noise • L/D improvements reduce takeoff, community, and climb-to-cruise noise levels.
Stability and Control .....
• Leading-edge devices have a positive effect on longitudinal stability and lateral control effectiveness.
Inteqration • Must be integrated with LFC and advanced engine nozzles.
Figure 5
EFFECT OFHIGH-LIFT ONTOGW ANDENGINE THRUST
The figure shows results of recent system studies indicating a significant
increase in L/D (at appropriate takeoff conditions) due to optimum leading
edge deflections. This increase in aerodynamic efficiency will provide
corresponding reductions in takeoff thrust and TOGW.Note that for the
tailed configuration that was analyzed, best trailing-edge deflections
were about 10 to 15 degrees in the trimmed mode.
Effect of High-Lift Settings
at Takeoff
+2. +0.08i +0.061 LE UNDEFLECTED .......
L/D CLat L/D UNDEFLECTED _sE,----f--_---_.
BASE_ ....
o 1"o 2'0 30 0 10 20 30 TE FLAP, DEG TE FLAP, DEG 20.0%" 4.00%- 2.00%- 10.0% BASE - THRUST BASE' MTOGW -2.00%, -m.OO/o_ -4.00%' -20.0% -6.00% 10 20 30 0 1() 20 30 TE FLAP, DEG TE FLAP, DEG Figure 6 EFFECT OF L/D ON SIDELINE, TAKEOFF, AND APPROACH JET NOISE The figure shows that for a given configuration, the L/D improvements can reduce the takeoff and approach noise levels. However, no significant reduction of sideline noise was obtained with the L/D increase.
Effect of L/D on Sideline, Takeoff, and Approach
P&W TURBINE BYPASS CYCLE WITH MIXER/EJECTOR BASE Z_ EPNLdB SIDELINE -10 -20 BASE EPNLdB -10 TAKEOFF
,° i
-o -20 lo BASE t A EPNLdB APPROACH _D -10 t -20 5 6 8 9 10 (UD) Figure 7 SUBSONIC CLIMB AND CRUISE PERFORMANCE REQUIREMENTS As indicated earlier, there is a large segment of the mission where an improvement in subsonic aerodynamic efficiency is needed because 25-percent of the range is being flown at subsonic conditions. The figure shows that a significant increase in L/D could be obtained with optimum leading-edge deflections at subsonic speeds. There is also a beneficial increase in C L at which L/D maximizes when flaps are deployed. This means that the flap systems required for the low-speed, high-lift segment will also have to be deployed in the subsonic mode. We should include this requirement as part of the high-lift technology development.
Subsonic Climb and Cruise
Performance Requirements
FROM MACH 0.40 TO 0.95 L/D TRIMMED
; ii Defece
,_ C L Range for Subsonic Climb and Cruise I ' I I ' I I ' 0.0 0.2 0.4 0.6 0.8 1.0 1.2 C L Figure 8 HSCT HIGH-LIFT AERODYNAMIC GOALS We have established aerodynamic goals for a desirable high-lift system based on recent system studies. The goals are presented for the takeoff, approach, and subsonic climb and cruise modes. It is believed that these goals are attainable within the expected 1998 technology availability date. An important aspect here is that if the wing and its high-lift system has to perform significantly better than certain minimum requirements, the wing planform may be compromised which may lead to a large penalty on the supersonic aerodynamic efficiency, this in turn will cause large weight and economic penalties.
GoalF
-HSCT High-Lift Aerodynamics
(Trimmed Conditions)
Takeoff
CL Ground Angle Limit > 0.75
(L/D) Second Segment Climb > 8.0
LE Suction FactorSecond Segment Climb > 0.8
Approach
(L/D)Approach > 7.5
LE Suction FactOrApproach > 0.8
Climb
(L/D)M = 0.5 _o 0.95
> 14
1776 Figure 9
HSCT HIGH-LIFT TECHNOLOGY STATUS
There is a good set of high-lift wind tunnel databases available for the
past supersonic transport configurations. These data were mainly obtained
at conventional wind tunnel Reynolds numbers. The flap design
methodologies developed by Carlson, Frink, etc., at NASA Langley are
quite useful to aerodynamic designers for guiding them toward optimum flap
designs. The CFDcodes will have to be calibrated for application to
flowfields associated with HSCT wings and flaps.
HSCT High-Lift Technology Status
• Extensive SST, SCAR, SCR, and AST databases are available.
• Flap design methodologies (by Carlson, Frink, etc.) based on linear
subsonic flows and L E suction/vortex lift corrections are available.
Navier-Stokes codes are available. However, the codes and their
turbulence models need to be calibrated and verified for their
application to highly 3-D, vortex-dominated, separated flowfields.
Figure i0 NASA 0.I-SCALE LOW-SPEED MODEL OF DOUGLAS AST CONFIGURATION An example of an available model for high-lift testing is shown here. This particular 0.l-scale model is for the NASA/Douglas Mach 2.2 Advanced Supersonic Transport configuration, with the aspect ratio 1.84, leading-edge sweep 71/57-degree wing planform. The model has been tested in the Langley 30-by 60-foot tunnel with a full wing/high-lift-system/tail/nacelle configuration. A plan for testing this model with new flaps is being formulated.
OR',TGINAL PAGE BLACK AND WHITE PHOTOGRAPH Figure ii
EXAMPLE OF NAVIER-STOKES/EULER CODES APPLICATION
An example of MDC application of the CFL3Dcode in the Euler and
Navier-Stokes modesfor a delta wing is shownhere. A good comparison of
the predicted vortex location using the code with the test data is shown.
Further work is being done for the application of this and similar codes
to the HSCTtype planforms with flaps.
Example of Navier-Stokes/Euler Codes
Application
Ref. MCAIR 90 - 021
Medium Mesh, Moo = 0.30, Re c = 1 x 106, (x = 20 o
Plenform View Euler ...... l..aminaf --- :" ..... Turbulent .... .-._ i n Experiment ...-! "_ e,- u_-" " _1.
Chordwtsa Distance, x (No Vorlex Burst Over Wing Surface) Rear View Note: Scale kncteased 2x Side View N _: .-m_":¸j c / / i:5 o _S'": .....
'_ _ '_'_w'_m .r/ t_/ Chordwise Distance, x z r_ _" ..............
SpanwlseDistance,y Figure 12 1779 HSCT HIGH-LIFT RESEARCH AND TECHNOLOGY AREAS Various high-lift research and technology areas for future work are listed in this figure. Each topic is discussed on the following pages.
HSCT High-Lift
Research and Technology Areas
• Innovative Concepts Verification.
• Flap Design Methodology Application and Verification.
• CFD Calibration and Application.
• High Reynolds Number Testing.
• Subsonic/Transonic Flap Optimization.
Flight Testing.
1780 Figure 13
SOME CANDIDATE INNOVATIVE HIGH-LIFT CONCEPTS
Someof the candidate innovative concepts are shown here. The vortex flap
concept, apex fence, deployable canards/strakes, apex blowing, etc., have
a potential for improving L/D, C L, and trim control to varying degrees.
Someof these concepts have been tested by NASAin the past. Further work
is required for a full assessment of the benefits and risks of each
concept.
Some Candidate Innovative High-Lift Concepts
• VORTEX FLAP • APEX FENCE • DEPLOYABLE CANARD/STRAKE • APEX BLOWING Figure 14
APPLICATION ANDVERIFICATION OF CURRENT L.E. FLAPDESIGN METHODOLOGIES
The important area of applied methods development and verification is
discussed in this figure. Douglas is currently applying the
Carlson-Darden flap design and analysis codes and Frink vortex flap design
code to the HSCT high-lift problem. The near-term objective is to select
flap configurations for verification in the NASA Langley 30- by 60-foot
tunnel with the NASA 0.I model of the Douglas ASTconfiguration. A
parallel CFDapplication to the flap design process is also planned before
final flap configurations are selected for advanced testing, e.g., high-Re testing.
Application and Verification of Current
L.E. Flap Design Methodologies
I AST/SCR WIND TUNNEL MODELS I
,,_
t
FLOW METHOD SAERO2, SWDES2 METHOD I
t
I 'NTEGRATED F_P DES,GN(S) l
NASA 10% MODEL OF DAC AST T 30_X $Q_ W!ND TVNNEL TEST IB I CFD I !
I
T
FINAL L.E, FLAP DESIGN FOR INTEGRATION
I 1 WITH HIGH LIFT SYSTEM
HIGH Re NO.VERIFICATION TESTING 1782 Figure 15
CFDCALIBRATION ANDAPPLICATION NEEDS
CFDcalibration and application needs are listed in this figure. The
codes and their turbulance models will have to be verified for their
application to the complex 3-D viscous, vortex-dominated, separated
flowfields. Weneed to agressively pursue this area so that the codes can
be madeavailable for the flap design process. The goal is also to be
able to analyze full wing/body/tail/nacelle configurations by the
1995-1998 timeframe. These codes will also allow us to predict
aerodynamic loads with vortex effects - a very improtant input to the
structural design process.
CFD Calibration and Application Needs
• Understand complex 3-D viscous flowfield around low AR, high sweep
wings with and without flaps.
• Understand L E vortex development and breakdown.
• Guide flap design process.
• Study high Reynolds number effects.
• Analyze full trimmed configurations (body, tail, and nacelle effects).
• Predict aerodynamic loads.
Figure 16 1783 HIGH REYNOLDS NUMBER RESEARCH AND TECHNOLOGY Areas of high Reynolds number research and technology development are shown in this figure. The HSCT full-scale Reynolds number in the takeoff and approach modes is typically on the order of 100-150 million based on a wing mean aerodynamic chord. Most of the test data are available at a conventional Re of about 4 million. The effect of higher Re will have to be simulated in the NTF, 12 foot, or 40- by 80-foot tunnels. These results will help in selecting candidate concepts for flight testing.
Hicjh Reynolds Number
Research and Technology Areas
• Understand dependency of vortex formation and leading-edge suction on
wing leading-edge radius and Reynolds number (Re).
• Study effectiveness of flaps (L E and T E), strakes, and fences at high Re.
• Study tail effectiveness at high Re.
• Generate data for CFD code validation.
• Select final flight test configurations through parametric testing at high Re.
1784 Figure 17
SUBSONIC CLIMB/CRUISE FLAPOPTIMIZATION TECHNOLOGY
As stated earlier, flap settings must be optimized and verified for
subsonic climb and cruise to enhance performance. CFDand high-Re
technology development activities should reflect this need.
Subsonic Climb/Cruise Flap Optimization
Technology Areas
• Determine and validate optimum flap settings for subsonic climb and cruise.
• Apply CFD codes to the design process.
• Verify designs through high Re testing.
Figure 18 1785 ROLE OF FLIGHT TESTING IN THE HSCT HIGH-LIFT RESEARCH AND TECHNOLOGY DEVELOPMENT This figure addresses the role of flight testing in the high-lift research and technology areas. For many purposes, a high Reynolds number wind tunnel test may be quite sufficient. However, a cost-effective flight test could provide additional data beyond the wind tunnel testing. The flight testing could be the most appropriate means of simulating interactions between high-lift devices and an actual engine noise-reduction system.
Role of Flight Testing in the High-Lift Research
and Technology Development
High-Re wind-tunnel testing (in,e.g., NTF, 12', 40'x 80') can be utilized for: - Understanding basic high Re effects.
- Sorting out configurations.
- Generating large controlled databases for pressures and forces and
moments.
• Flight testing of aircraft with appropriate AR and sweep can be suitable for: Observing flow phenomena not simulated in the tunnels.
- Generating clean data without wall, ground, and support system
interference.
- Validating final high-lift concepts.
- Simulating interactions between high-lift devices and engine
noase reduction systems (suppressors, ejectors, mixers, etc.).
Cost effectiveness of either approach can be a major decision factor in
scoping various technology development plans.
1786 Figure 19
HSCT HIGH-LIFT TECHNOLOGY DEVELOPMENT NEAR-TERM PLAN
An HSCT high-lift technology development near-term plan is shown in this
figure. BI and B2 represent updated 1991 and 1992 baselines with their
respective optimized wing planforms and engine cycles• In additon to the
innovative high-lift concepts verification, the Carlson's and Frink's
linear methods will be applied for flap designs in the near term. The
long-term plan is to apply CFDto the wing (W) and its flaps by 1992,
followed by its application to the wing-body (WB) and a full B2 baseline
configuration. Most of the wind tunnel test verification may be required
for the B2 configuration• However, there may be a need for an interim
small-scale testing of the BI configuration. The final configuration
validation testing may involve someflight-testing and/or 40- by 80- foot
wind tunnel testing.
H$CT HIGH-LIFT TECHNOLOGY DEVELOPMENT NEAR-TERM pLAN
1995 1996 1991 1992 1993 1994 Actlvltloe iii I
JX ,\
• Review High-Lill Needs _1 _- Engine :_2 • Baseline Configuration Updates L ..........
I1,2 • Innovative Concepts • Linear Methods Application
j_2
• CFD Application I1
N
• Small-scale Testing AST • Large-scale Testing _ts /,_ 2
J\
• High-Re Testing B2 1\ /_, • Transonic Testing
A
• Final Conliguration Validation
A ............... _ /_
• Control System Integration and Simulation Figure 20 1787 CONCLUSIONS Some general concluding remarks are made in this figure. It is believed that with an aggressive technology development effort, the high-lift aerodynamic goals can be met.
Conclusions
" Efficient high-lift, high L/D system for HSCT is required to minimize
TOGW, improve economics, and help meet noise goals.
Optimum flap settings will be required to operate at max L/D in the
subsonic climb and cruise segments. There is a scarcity of database in
this area.
Future enabling technology/research needs include verification of new
high-lift designs, aggressive CFD application, flight test verifications, and high Reynolds number testing.
Figure 21