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**CINCINNATI**

**5 _ _ _"**

FINAL REPORT

AN INVESTIGATION OF BLEED CONFIGURATIONS AND THEIR EFFECT

**ON SHOCK WAVE/BOUNDARY****LAYER INTERA(_TION_;**

**Awatef Hamed**
**Principal Investigator**

CO *-I

-NASA Grant **NAG3-1213LE** o _ **o,**

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* lO.October 1990 - 26 June 1995* i

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**fr_****Submitted to**_

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**tJ.o****Dr. John D. Saunders, Project Monitor****_ ___ _ _** _;.

**NASA Lewis Research Center, MS 86-7****_ _:I... >.. 0** _eC **.**._

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**TABLE OF CONT_NT_****ABSTRACT ...****1**
**INTRODUCTION ...** **1**
**ANALYSIS ...** **2**
SUMMARY ... **2**

**1. Effect of Nomud Bleed Slot Location in LaminarBoundary****Layer/Shock Interaction ...****2**

**2.. Effect of Bleed Mass Flow Through a Normal Slot in Shock-Wave/****Turbulent-Boundary Layer Interactions ...** 2

**3.. Effect of Normal Bleed Configuration ...** 3

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**4. Effect of Bleed Slot Angle and Location ...** **4**

**5. Plenum Interactions ...** **4**
**I_EF_R'ENC** **]_ S** ... 5
**APPENDIX A ...** **7**
**APPE_DIX** B ... **15** .
**APPENDIX C...** **25**
**I"**
**APPENDIX** **V** ... 36
**APPENDIX E ...** **47** i'
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**AN INVESTIGATION OF BLEED CONFIGURAT_QN_AND THEIR EFFECT**

**ON SHOCK WAVE/BOUNDARY LAYER I]_TERACTIONS**

**ON SHOCK WAVE/BOUNDARY LAYER I]_TERACTIONS**

**ABSTRACT**

**The designof high efficiencysupersonicinletsis a complextask involvingthe**

**optimizationof a numberof performanceparameterssuchas pressurerecovery,spillage,**

**optimizationof a numberof performanceparameterssuchas pressurerecovery,spillage,**

**drag, and exit distortionprofile,over the flightMach numberrange. Computational**

**techniquesmustbe capableof accuratelysimulatingthe physicsof shock/boundarylayer**

**techniquesmustbe capableof accuratelysimulatingthe physicsof shock/boundarylayer**

### _

**interactions,secondarycomer flows, flow separation,and bleedif theyare to be useful in**

**interactions,secondarycomer flows, flow separation,and bleedif theyare to be useful in**

**the design. In particular,bleedand flow separation,playan importantrole in inletunstart,**

**the design. In particular,bleedand flow separation,playan importantrole in inletunstart,**

**andthe associatedpressureoscillations. Numericalsimulationswere conductedto**

**investigatesomeof the basicphysicalphenomenaassociatedwith bleedin obSqueshock**

**wave boundarylayerinteractionsthat affecttheinlet performance.**

**INTRODUCTION**

**INTRODUCTION**

**Theexperimentalmeasurementsin most mixed compressioninlettests are limitedto**

**the staticpressuresover the innersurfacesand total pressurerecovery at the engineface**

**[1]. In a few experimentalstudies, someboundarylayerprofilemeasurementswere**

**[1]. In a few experimentalstudies, someboundarylayerprofilemeasurementswere**

**obtainedfrompitot pressurerakesaheadand behindthe shock/boundarylayer/bleedregions**

**obtainedfrompitot pressurerakesaheadand behindthe shock/boundarylayer/bleedregions**

**[2-5]. Comparisonsof flow computationalresultswith the experimentalmeasurementsin**

**supersonicinletsrevealeddiscrepanciesin the predictionof shock locations, andvelocity**

**supersonicinletsrevealeddiscrepanciesin the predictionof shock locations, andvelocity**

**profilesafterthe interactions[6-8]. A betterunderstandingof these interactionsis essential**

**to improvinginlet performancepredictions.**

**The purpose of the presentinvestigationis to characterizethe flow field in the**

**obSque shock wave/boundarylayer/bleedinteractionregionand to develop a basic**

**obSque shock wave/boundarylayer/bleedinteractionregionand to develop a basic**

**understandingof flow separationcontrolmechanisms. Theflow computationswere carried**

**out for differentbleedconfigurations,and shock strengths. Thesolutiondomainextended**

**acrossthe interaction,and insidethebleed slots. A systematicinvestigationwas conducted**

### .

**to determinethe effects of the bleedlocationrelativeto the shock, slot width,depthand slot**

**to determinethe effects of the bleedlocationrelativeto the shock, slot width,depthand slot**

**i',**

**i',**

**angle, on the flow characteristicsand thebleed performanceparametersat differentbleed**

### _

**massflow rates [9-13]. The obtainedflow characteristicsinsidethe bleed portwere**

**comparedwith the recentlyobtainedexperimentalmeasurements[14, 15] with and without**

**incidentshockat NASA Lewis ResearchCenter.**

**TheresuRsof the bleedinvestigationwere presentedintwo formats,one givingthe**

**flow detailsin orderto understandthe natureof the interaction,andanothergivingthe**

**bleedperformanceparameterssuchas the dischargecoefficientand total pressurerecovery**

**which are usefulto the designer. The detailedpressureandMach numbercontoursas well**

**as velocityprofileswithinthe interactionzone andinsidethebleed slots revealedthe**

### !

**i"**

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**importantflow physicsandthe mechanismsaffectingthe flow separationand demonstrated**

### _i

**thevariationinthe bleedflow velocities, andpressuregradientdistributionacrossthe bleed**

**port. Onthe other hand,the bleedperformanceresultsin the form of bleedefficiencyand**

**port. Onthe other hand,the bleedperformanceresultsin the form of bleedefficiencyand**

**pressurerecoveryat differentplenumpressuresand for differentbleedconfigurationsis**

**usefulin selectingthe optimumbleed configurationininlet designs.**

**ANALYSIS**

**The s_lutiondomainfor the compressibleNavier-Stokesequationsextendedinside**

**the bleed slot andupstreamand downstreamthe interactionregion. Thechangein bleed**

**(suction) massflow was accomplishedin the numericalinvestigationthroughchangingthe**

### t

**static pressure atthe bottomof the bleed slot over a widerange coveringchoked and**

**unchokedflow conditions. The PARCcode [16] was selected afterit was validated[10]**

**for the case of separated SWTBLIat Mach2.96 through comparisonwith Law'_[17]**

**experimentaldata. Themesh spacingwas variedin boththe streamwise,and normal**

**directionsto capturethe importantflow characteristicsin the shock wave boundarylayer**

**directionsto capturethe importantflow characteristicsin the shock wave boundarylayer**

**interactionsand.insidethe bleed port.**

**SUMMARY**

### !,

**1.**

**Effect of Normgl Blced Slot Location in Laminar Bgpndary Laygr/Shock**

**Effect of Normgl Blced Slot Location in Laminar Bgpndary Laygr/Shock**

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**Interaction**

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**A studywas conductedforbleeclthrc_1|_a normalslot atthree locationsupstream,**

**acrossand downstreamthe shock [9].**

**Theexternalflow conditionswere M_ = 2.0,.**

**Theexternalflow conditionswere M_ = 2.0,.**

**Re®= 1.812×10_/fl.,and an impingementobliqueshockangle of 32.585 deg.,**

**Re®= 1.812×10_/fl.,and an impingementobliqueshockangle of 32.585 deg.,**

**correspondingto the experimentaltest conditionsofHakinen et al. [18] withoutbleed. The**

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**bleedslot width ofD = 0.011 inchwas equal to theboundarylayerdisplacementthickness**

**8*beforethe interactionat x = 1.96 inchfi'omthe fiatplateleadingedge (I)/8'=1) and the**

**8*beforethe interactionat x = 1.96 inchfi'omthe fiatplateleadingedge (I)/8'=1) and the**

**slot depthwas three times its width(L/D= 3.0). For a givenplenumpressureatthe slot**

**slot depthwas three times its width(L/D= 3.0). For a givenplenumpressureatthe slot**

**exit, it was foundthatthe shock inducedflow separationon theplate surfacewas eliminated**

**in theacrossthe shockbleedconfiguration,but only reducedforthe othertwo bleed**

**locations. The resultsof this investigationwere publishedin the Journalof Propulsionand**

**Power, Vol. 11, No. 1,pp. 42-48, Jan.-Feb.1995, and presentedas AIAA Paper9_-2014**

**Power, Vol. 11, No. 1,pp. 42-48, Jan.-Feb.1995, and presentedas AIAA Paper9_-2014**

**entitled"The Effect of Bleed Configurationon ShockLaminarBoundaryLayer**

**Interaction,"at the JointPropulsionConferencein Pasadena,CA, June 14-16, 1991**

**Interaction,"at the JointPropulsionConferencein Pasadena,CA, June 14-16, 1991**

**(AppendixA).**

**2.**

**Effect of Bleed Mass Flow Thrgngh a Normal Slot in **

**Effect of Bleed Mass Flow Thrgngh a Normal Slot in**

**Shock-Wave/Turbulent-Boundary-Laver Interaction**

**A studywas completedto investigatethe effect of bleed massflow in a normalslot**

### 4

**M_ = 2.96, Re_: 1.2xl0_/R., andimpingingobliqueshockangle of 25.84 degree,**

**M_ = 2.96, Re_: 1.2xl0_/R., andimpingingobliqueshockangle of 25.84 degree,**

**correspondingto the experimentaltest conditionsof Law [17] withoutbleed. The bleed**

**slot widthwas D = 0.0213 _. which is equalto 1.617timesthe boundarylayerthickness8**

**upstreamof the interactionatx = 0.9 fL (D/8 = 1.617), andthe bleedmass flow variedup**

**upstreamof the interactionatx = 0.9 fL (D/8 = 1.617), andthe bleedmass flow variedup**

**to chokedconditions(30%of the incomingboundarylayermassflow). Thecomputed**

**to chokedconditions(30%of the incomingboundarylayermassflow). Thecomputed**

**bleed results[10] indicateda complexexpansionand compressionwave structureacrossthe**

**bleed results[10] indicateda complexexpansionand compressionwave structureacrossthe**

**slot openingdue to bleedflow entrainment.Thenet effectof the bleedon the flow**

**downstreamis to reducethe momentumand displacementthicknessand to move the**

**reflectedshock closerto the surface. Thereductioninthe momentumthickness**

**downstreamof the interactionincreasedwith theincreasein bleedmass flow, but eventually**

**downstreamof the interactionincreasedwith theincreasein bleedmass flow, but eventually**

**plateaud. Thiswork was publishedin the Journalof Propulsion_d Power, Vol. 10, No. 1,**

**plateaud. Thiswork was publishedin the Journalof Propulsion_d Power, Vol. 10, No. 1,**

**pp. 79-81, Jan.-Feb.1995, and presentedas AIAA Paner92-3085 entitled"An**

**Investigationof Shock/TurbulentBoundaryLayer/BleedInteraction,"atthe Joint**

**Investigationof Shock/TurbulentBoundaryLayer/BleedInteraction,"atthe Joint**

**PropulsionConferenceinNashville,Tennessee,July_**

**6_8,_L992(AppendixB).**

**6_8,_L992(AppendixB).**

**3. Effect of Normal Bleed ConfigurAtion**

**A parametricstudy was conductedto determinetheeffect of normalbleed slot**

**configurationon shockwave turbulentboundarylayerinteractions[11]. Theexternalflow**

**conditionswere Moo= 2.96, Re_ = 1.2xl07/fL andobliqueshockimpingementangle of**

**conditionswere Moo= 2.96, Re_ = 1.2xl07/fL andobliqueshockimpingementangle of**

**25.84 degree. Differentslot width,depthandinclinationwere investigated. The resultsof**

**25.84 degree. Differentslot width,depthandinclinationwere investigated. The resultsof**

**the parametric investigationof the normalbleed slot configurationin STBLIwere presented**

**as AIAA Paver 93-0294 entitled"A ParametricStudyof Bleed in ShockWaveBoundary**

**as AIAA Paver 93-0294 entitled"A ParametricStudyof Bleed in ShockWaveBoundary**

**LayerInteractions,"atthe 31st AerospaceSciencesMeetingin Reno, Nevada, **

**LayerInteractions,"atthe 31st AerospaceSciencesMeetingin Reno, Nevada,**

**January11-14, 1993 (AppendixC).**

**(a)**

**Slot Width**

**Flow computationalresults were obtainedover a wide rangeof bleed massflows for**

*-_*

**threedifferentslot widths0.8, 1.6 and 3.2 times the boundarylayerthicknessupstreamof.**

**'.'_**

**'.'_**

**the interaction[14]. Theresultsindicatethatthebleed dischargecoefficientand total**

**pressurerecoveryare not very sensitiveto the bleedslot width.**

**(b)**

**Slot Asoect l_ti 0**

**.,**

**Two slot aspect ratios= 3 and 6 were investigatedfor the intermediateslot width.**

**Both the dischargecoefficientand the momentumthickness downstreamof the interaction**

**were sensitiveto changes in L/D_d bothimprovedas the aspect ratioincreased.**

**were sensitiveto changes in L/D_d bothimprovedas the aspect ratioincreased.**

:!

**Additionalflow computationswere performedforthree differentbleed locations**

**relativeto the shock impingementpointfor thewidest bleedslot (D/8 = 3.2) over a range of**

**relativeto the shock impingementpointfor thewidest bleedslot (D/8 = 3.2) over a range of**

**bleedmass flows up to chokedconditions. Theupstream,across,and downstreambleed**

**bleedmass flows up to chokedconditions. Theupstream,across,and downstreambleed**

**slot locationscorrespondedto the slot centerat -D, 0 and +D relativeto the shock**

**slot locationscorrespondedto the slot centerat -D, 0 and +D relativeto the shock**

**impingementpoint. Theresultsindicatethatacrossthe shockbleedgives the largest**

**impingementpoint. Theresultsindicatethatacrossthe shockbleedgives the largest**

**reductioninthe momentumthicknessdownstreamof the interactio..,t**

**reductioninthe momentumthicknessdownstreamof the interactio..,t**

**at all bleedmass flows.**

• **|**

**However, the total pressure recovery at the bleed slot exit was higherfor downstream**

**bleed.**

**4.**

**Effect of Bleed Slot Anale and Location**

**Detailedflow computations[12] were performedfor 20° slantedand 90° normal**

**slot_at threedifferentlocationsupstream,acrossanddownstreamof the inviscidshock**

**slot_at threedifferentlocationsupstream,acrossanddownstreamof the inviscidshock**

**impingementlocationrelativeto the flatplate surfaceat Moo= 2.96, Re_ = 1.2xl07/ft. and**

**impingementlocationrelativeto the flatplate surfaceat Moo= 2.96, Re_ = 1.2xl07/ft. and**

**obliqueshock impingementangle of 25.84 deg. Theslot openingwas kept the samefor**

**both slots with D/8 = 0.8085 for the normalslot and 0.2766 for the 20° slanted slot. The**

**both slots with D/8 = 0.8085 for the normalslot and 0.2766 for the 20° slanted slot. The**

**resultsindicatea largerecirculatingflow regioninsidethe normal slot butnot in the20°**

**slantedslot causingthe chokeddischargecoefficientto morethantriple. Bleed through the**

**slanted slot producedredevelopingboundarylayerdownstream,with a higherfriction**

**coefficient. Thelargestreductionin theboundarylayermomentumand displacement**

**thicknessdownstreamof the interactionwere associatedwith the normal slot bleedacross**

**the shock.**

**The slanted bleed dischargecoefficientwas found to be more sensitiveto bleed**

### _

**location and hadthe highest valuewhen thebleed slot was located upstreamof the shock.**

**Normalbleed acrossthe shockresultedin the largestreductionsin bothboundarylayer**

**displacementandmomentumthicknessdownstreamof the interaction. Theresultsof this**

**investigationwill appearin 3ournalof PropulsionandPower, Vol. 11,No. 6, Nov.-Dec..**

**investigationwill appearin 3ournalof PropulsionandPower, Vol. 11,No. 6, Nov.-Dec..**

**1995 entitled"Shock-WaveBoundary-LayerInteractionswith Bleed, Part2: Effect of Slot**

**Location," andwere presentedas AIAAPacer 93-2992 entitled"An Investigation of Shock**

**Location," andwere presentedas AIAAPacer 93-2992 entitled"An Investigation of Shock**

**Wave TurbulentBoundaryLayerInteractionwith Bleed Through Slant_ Slots," in**

**Wave TurbulentBoundaryLayerInteractionwith Bleed Through Slant_ Slots," in**

**._**

**Orlando,Florida, :July1993 (AppendixD).**

*a*

**5.**

**Plenum Interactions**

**.**

**_'_,**

**Thenumericalinvestigationof shock-wave/turbulent**

**Thenumericalinvestigationof shock-wave/turbulent**

**boundary-layer/bleed**

**boundary-layer/bleed**

**interactionswas conductedwith a plenumatthe end of thebleed slot [13]. Theresults**

**were compared with the experimentaldataobtainedby Williset al. [14] and Davis et al.**

**i"**

**[15] in the l'xl' supersonictunnelatNASA Lewis Resem'chCenter. In this studythe**

**[15] in the l'xl' supersonictunnelatNASA Lewis Resem'chCenter. In this studythe**

**externalflow conditionswere 1_ = 2.46, Re_ - 1.81xl07/fl., andthe ratioof the slot**

**externalflow conditionswere 1_ = 2.46, Re_ - 1.81xl07/fl., andthe ratioof the slot**

**'**

**widthwas one thirdthe incomingboundarylayerthicknessbeforethe interaction0)/8 =**

**widthwas one thirdthe incomingboundarylayerthicknessbeforethe interaction0)/8 =**

**i:_,**

**1/3).. Theflow simulationswere.performed over a rangeof plenumpressuresto simulate**

**1/3).. Theflow simulationswere.performed over a rangeof plenumpressuresto simulate**

**increasedbleed massflow ratesup to chokingfor two shock strengthscorrespondingto**

**shock generatorwedge angle of 0° and 8o. Thecomputationalresultswith andwithoutthe**

**plenumindicatedthatthe interactionbetweenthe plenumandthe recirculatingflow inside**

**the slot caused fluctuationsin thebleed mass flow at the slot exit. Thesevariationswere**

**associatedwith the changesin the size of the separatedflow regionsover both slot walls at**

**exit. However,the bleedmass flow at the slot openingdid not fluctuateand remained**

**steady atthe meanvalue of the exit mass flow. The comput.edbleed massflow atthe slot**

**inlet were in good agreementwiththe experimentalmeasurements.These resultswere**

**inlet were in good agreementwiththe experimentalmeasurements.These resultswere**

**presentedin AIAA Paper95-0033, "How Characteristicsis inBoundaryLayerBleed Slots**

**with Plenum,"atthe 33rd AerospaceSciencesMeeting,inReno, Nevada, January9-12,**

**with Plenum,"atthe 33rd AerospaceSciencesMeeting,inReno, Nevada, January9-12,**

### i

**1.995(AppendixE).**

**REFERENCES.**

**1.. Hamed, A. and Shang,J.,"Survey andAssessmentof ValidationData Base for **

**Shock-Wave/Boundary-Layer**

**Shock-Wave/Boundary-Layer**

**InteractionsinSupersonicInlets," AIAA Paper89-2939, J¢!y**

**InteractionsinSupersonicInlets," AIAA Paper89-2939, J¢!y**

**1989. To appearin the Journalof PropulsionandPower, October 1991.**

**1989. To appearin the Journalof PropulsionandPower, October 1991.**

**2. Hingst,W.R. andJohnson,D.F., "ExperimentalInvestigationof BoundaryLayersin an**

**2. Hingst,W.R. andJohnson,D.F., "ExperimentalInvestigationof BoundaryLayersin an**

**Axisymmetric,Math 2.5 MixedCompressionInlet," NASA TMX-2903, 1973.**

**Axisymmetric,Math 2.5 MixedCompressionInlet," NASA TMX-2903, 1973.**

**3. Fukuda,M.K., I-Iingst,W.G. andReshotko,E., "Controlof ShockBoundaryLayer**

**3. Fukuda,M.K., I-Iingst,W.G. andReshotko,E., "Controlof ShockBoundaryLayer**

**Interactionsby Bleed in Mixed CompressionInlets,"NASA CR 2595, 1975.**

**Interactionsby Bleed in Mixed CompressionInlets,"NASA CR 2595, 1975.**

**4.. Fukuda,M.K., Hingst,W.G. and Reshotko,E., "Bleed Effects on **

**4.. Fukuda,M.K., Hingst,W.G. and Reshotko,E., "Bleed Effects on**

**Shock/Boundary-LayerInteractionsin SupersonicMixedCompressionInlets,"Journalof Aircraft,Vol.**

**Shock/Boundary-LayerInteractionsin SupersonicMixedCompressionInlets,"Journalof Aircraft,Vol.**

**14,No. 2, February1977, pp. 151-156.**

**14,No. 2, February1977, pp. 151-156.**

**5. Carter,T.D. and Spong,E.D., "High-SpeedInletInvestigation.Vol. I - Descriptionof**

**5. Carter,T.D. and Spong,E.D., "High-SpeedInletInvestigation.Vol. I - Descriptionof**

**Programand Results;Vol. H - Data Summary,"AFFDL-TR-77-105,November1977.**

**Programand Results;Vol. H - Data Summary,"AFFDL-TR-77-105,November1977.**

### ._.

**6. Knight,D.D., "Calculationof High SpeedInlet FlowsUsing the Navier-Stokes**

### s

**Equations,"Vol. I: Descriptionof Results," AFFDL-TR-79-3138,February1980.**

**Equations,"Vol. I: Descriptionof Results," AFFDL-TR-79-3138,February1980.**

**7.. Knight, D.D., "ImprovedCalculationof High Speed InletFlows. PartI - Numerical**

**Algorithm," AIAA Journal, Vol. 19, No. 1, January1981, pp. 34-41, and"PartII :**

### _

**Results," ALkAJournal,Vol. 19, No. 2, February1981,pp. 172-179.**

**Results," ALkAJournal,Vol. 19, No. 2, February1981,pp. 172-179.**

**8. Saunders,J.D. and Keith, T.G. Jr.,"ResultsfromComputationalAnalysisof a Mixed**

**8. Saunders,J.D. and Keith, T.G. Jr.,"ResultsfromComputationalAnalysisof a Mixed**

**CompressionSupersonicInlet," AIAA Paper91-2581, 1991.**

**_.**

*i*

**9. Hamed, A. and Lehnig,T., "An Investigationof ObliqueShock/BoundaryLayer/Bleed**

**9. Hamed, A. and Lehnig,T., "An Investigationof ObliqueShock/BoundaryLayer/Bleed**

*'*

**Interaction,"gQUrnal**

**Interaction,"gQUrnal**

**of PropulsionandPower, Vol. 8, No. 2, 1992, pp. 418-424,**

**of PropulsionandPower, Vol. 8, No. 2, 1992, pp. 418-424,**

**10. HeLmed,**

**A., Shih,S. and Yeuan,**

J.J., **A., Shih,S. and Yeuan,**

**"Investigationof Shock/TurbulentBoundary**

**"Investigationof Shock/TurbulentBoundary**

**Layer/BleedInteractions,"Journalof PropulsionandPower, Vol. 10,No. 1, Jan.-Feb.**

**Layer/BleedInteractions,"Journalof PropulsionandPower, Vol. 10,No. 1, Jan.-Feb.**

**1995, pp. 79-81.**

**11. Hamed,A., Shih,S.H. and Yeuan,**

**J.J.,**

**"A ParametricStudyof Bleed in Shock**

**BoundaryLayerInteractions,"AIAA Paper93-0294, Cincinnati,Ohio, January1993.**

**BoundaryLayerInteractions,"AIAA Paper93-0294, Cincinnati,Ohio, January1993.**

**12. Hamed, A., Yeuan, J.J. and Shih, S.H., "Shock-Wave Boundary-Layer Interactions with**
**Bleed, Part 2: Effect of Slot Location," to appear in Journal of Propulsion and Power,**
**Vol. 1I, No. 6, November-December 1995.**

**13. Hamed, A., Yeuan, J.J. and Jun, Y.D., "Flow Characteristicsin Boundary Layer Bleed**
**Slots with Plenum," AIAA Paper 95-003, 33rd Aerospace Sciences Meeting and****Exhibit, Reno, Nevada, January 9-12, 1995.**

**14. Willis, B., Davis, D. and I-Iinsst,W., "Flow Coefficient Behavior for_Boundary-Layer** ....

**Bleed Holes and Slots," AJAA Paper 95-003 I, 33rd Aerospace ScLences Meeting,****Reno, Nevada, January 9-13, 1995.**

**15. Devis, D., Willis, B. and I-Iinsst,W., "Flowfield Measurements in Slot-Bleed Oblique**
**Shock-Wave and TurbulentBoundary-Layer Interaction," AIAA Paper 95-0032, 33rd**
**Aerospace Sciences Meeting, Reno, Nevada, January 9-13, 1995.**

**16. Cooper, G.K. and Sirbaugh, J.R., "PARC Code: Theory and Usage," **

**AEDC-TR-89-15, 1989.** **.__**

**17. Law, C.H., "Supersonic Turbulent Boundary-Layer Separation," AIAA Journal, Vol.**
**12,_June 1974, pp. 794-797.**

**18. Hakkinen, R.J., C.rreber,I., Trilling, L. and Aberbanel, S.S., ,'The Interaction of an**

**Oblique Shock Wave with a Laminar_Boundary Layer," NASA Memo 2-18-58W,**

**March 1959.**

I

i I

**APPENDIX A**

**i ""**

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**IT**

**r J i + _**

**. _..'+**

**r _ "d_"**

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**--__**

**.**

**"**

**.--**

**"...**

*'*"

**""_**

***'J**

**+"**

**Vol.. I1. NL> I. Januury-Fcbru.',ry1995**

**Effect of Bleed Configuration on Shock/Laminar**

**Effect of Bleed Configuration on Shock/Laminar**

**Boundary-Layer Interactions**

**Boundary-Layer Interactions**

**A. Hamcd °**

**Unirer._ity of Cincimmti,****Citwinnati,***Ohio 45221*

**and**
**T. Lehnigt**

**Cold Jet, hw,,****Lor¢land,***Ohio 45140* **.**

**The flowfieldcharacteristicsare simulatednumericallyin an obliqueshockwave/laminarboundary.layer****interactionfor threedifferentbleedconfigurations.The numericalsolutionfor the flowfleldIsobtainedfoethe**

**strong c0nservation-lawformof the two,dimensionalcompressibleNavler.Stokesequationsust_ am Implicit****,.**

**scheme.Thecomputationsmodelthe flow in the interactionregionandInsidethe bleedslot foe an Impinging****obliqueshock of sufficientstrengthto cause boundary-layer****separationon a fiat plate boundarylays. The**
**computedresultsare presentedfor a normalbleedslot at threedifferentlocations:l) upstream°21acrou, and****3) downstreamof the shock Impingement****point.The detailedflowcharacteristicsin the Interactionzoneand****insidethe bleedslot are comparedfor the three Cases.The r_ulting surface pressureand shear stress and****boundary-layer****displacementandmomentumthicknessdistributionsarealsocOmpare¢!****forthethreeb!_ _____**
**andfor the shockwave/boundary.layer****!nteractionwithoutbleed.**

**Introduction** **effects of bleed hole size.t'.t4 and location relative to the**

**AIR**_{boundary-layer interactions when operating at super-}**bleed systems are used for controllingthe shock wave/****_hock._ t" Strike and Rippy" measured the surface pressure**_{in the interaction zone of an oblique shock wave impinging}**sonic speeds. Proper bleed system design is particularly ira-** **a turbulent boundary layer Over a flat plate, with suction.**
**portant for the efficient and stable, operation of mixed** **They determined that less suction is required to control **
**sup-compression supersonic inlets._ The fundamental objectives****aration, when applied upstream of the shOck. Seebaugh and**
**of supersonic inlet bleed system design are tO provide good****Childs"' investigated experimentally the axisymmetric flow in****aerodynamic flow characteristics with minimum boundary, -** **the interaction region of the boundary, layer inside a duct.**
**layer bleed. :._ The elimination or reduction of separation in****Contrary tO the conclusions of Strike and Rippy, _ suctiOn**
**shock wave/boundary,layer interactions _ is essential for con,****within the interaction region was found to be more effective****trolling the pressure loss and maintaining a stable flowfield** **in suppressing the effects of separation.**

**in supersonic inlets. Minimizing the bleed required to achieve** **The purpose of this study is to clarifythe effect of bleed ****loea-boundary-layer control allows the penalties associated with** **tion On controlling fl0w separation in shock **

**wave/bourldaty-incorporation of a supersonic inlet bleed system to be mini-** **layer interactions. Numerical computations are performed to**
**_-mized as well. These penalties include a loss****of****inlet mass****determine the flow characteristics in the interaction zone of****,,**
**flOWand an increase in drag due to venting of the bleed air*** an oblique shock wave/boundary layer, and wffhin a normal* ii_

**into the freestream. Ideally, removal of only that portion of**

**bleed slot, upstre_im, downstream, and across the oblique****the low-momentum boundary layer needed to inhibit sepa-****shock impingement point.****,**
**ration is desired.**

**Comparisons of internal flow computational results-'- 7with*** Computational Details* _.

**the experimental measurements in Supersonic inlets4." re-****The bleed study is Conducted initially for laminar flow, in**

**vealed reasonable agreement between the computed and** **order to allow the flowfield characterization to be **

**accom-measured surface pressures upstream of the ramp bleed. How-** **plished without the uncertainties associated with turbulence** **'**
**ever. discrepancies in the predicted shock locations and ve-** **modeling. The partial differential equations used to describe** *t':"_*
**Iocity profiles were observed downstream of shock/boundary-****the flow are the time-dependent compressible Navier-Stokes**

**layer interactions with bleed,****equations in strong conservation law form. The flow is treated****Hamed and Shang _reviewed the existingexperimental data** **as a perfect gas with molecular dynamic viscosity given by**
**base for shock wave/boundary-layer interactions in supersonic****Sutherland's law, and a gas conductivity based on a constant**
**inlets and other related configurations. According to this sur-****Prandtl number. An implicit approximate factorization**
**vey. there is enough experimental evidence¥- ,4 to indicate****technique '_is used in the numerical solution of the governing**
**that local bleed can control flow separation in shock wave/****equations. Prior to the bleed investigation, the code re.t7has**
**boundary-layer interactions. There are disagreements, t how-** **been validated for laminarshock wave/boundary-layer ****inter-ever, among the different experimental results regarding the** **actions both for separated and unseparated flows m by **
**com-paring the computational resultswith Hakkinen's **
**experimen-Pre._ntedas Paper91.2014at the AIAA/SAE/ASME/ASEE27th****tal data.*V _{The solution is obtained in a domain that includes the }**

**in-JointPropulsionConference,Sacramento,CA.June24-26. 1991;**

**teraction region and the interior of the bleed port as**

**shown****receivedAug. 2, 1991;revisionreceivedMay4, 1993;acceptedfor**

**publicationMay9, 1994.Copyright© 1991by theA-,tericanInstitute****schematically in Fig. I."l'h_.specified static pressure at the**
**of Aeronauticsand Astronautics.Inc. Allrightsreserved,** **bottom of the bleed slot simulates the plenum pressure that**
***Professor.Departmentof AerospaceEngineeringand Engineer-** **controls the bleed level for a given slot and flow configuration.**

**inkMechanics.Fellow**AIAA. **Zero-order interpolations are applied**for**the rest**ofthe **flow** **,**
**tSeniorPrOjeCtEngineer.MemberAIAA.** **variables at the bottom of the bleed slot. The no-slip **

**lJ','_ll** l,'-_%lJJl **II:_l(i** **iiIIJt** **I%1** **_.%ll,.j|'_.****Ii(/J** * _lJ._,l_l* J._ll

**I(. J'_l.;**

**I_. L,L.-IIIJ_I"I**

**t.1**, i

**..--.**

*_,_*

**C_tatLonaL**

**llmmdll¢}'****J**_

**_etLecte_t 8h_k NavO**

### I I

### I

**,.o,,. I**

**,.o,,. I**

**0.011"**

**Fig. I Schematicof the solutiondomainfor theshock-wave/boundary.layer/bleed****lnteractloa.**

**tion, adiabatic wall. and :,era normal pressuregradientsare****The flOWsOlution convergencemonitoring was based On**

**specified at the solid surfaces,The impinging shock wave is****the shearstress at the plate surfacer.. as follows:**
**explicitly introduced at the upper boundary using the **

**Ran-kine_Hugoniotrelations.Zero-orderextrapolationof the flow** **I r',: - r',: 'l****variables is enforced at the downstream boundary, which is** **_ =** **r',',**

**carefully positioned such that all generated or reflected shocks**

**exit through it.** **The specified convergence criterion was e <- 10 _ for the****The onhogonal grid spacing was varied in both the stream-****evaluation points at X < X,.. and e _ 10 ' for the evaluation****wise and normal directions to capture the important flow** **points located at X > X,. to account for the different rates****characteristics in the shock wave.boundary-layer** **interaction** **for convergence at the different locations from the plate ****lead-zone and inside the bleed Slot.t_The computational grid con,** *ing edge (where X,, is the tested shock impingement point*
**sisted of (243 X 107) mesh points in the streamwisc and****location) ...**

normal directions, respectively, with grid clustering _t the
*plate and around the slot walls. The following grid distribution*

**-was implemented in the solution of the shock.wave,'laminar****Results and Discussion**

**boundary-layer interactions with bleed:****Results are present,_d for the Computed flowfield in the****interaction zone Ofan oblique shock/laminar boundary-layer****interaeti0n with bleed applied through a normal slot at three**
**AF, -- 0.0375****77 -< j _ 1(17****(1)** **different locations relative to the shock impingement point.****The freestream conditions are 2.0 Math number and 2.t)6 ×****AY, = 1.12SAY****36._-1- _ 76****(2)** **10_ Reynolds number, based on the shock impingement **

**lo-cation, x = 1.96 in.. from the flat plate le;_dingedge. The**

• * shock angle of 32.585 deg corresponds to the test conditions* .

**_.\**

*1.5625 x 10__*

**AY,'=***(3)*

**28 _ j < 35**

**of Hakkinen et al. _''for the separated flow case. The com-***' '*

**putations are performed at the same freestream conditions****AY, - 1.125AY, ,,***I _ j _- 27* **(4)** **and shock strength, with bleed applied through a normal slot**

**that ts 0.011 in. wide and 0.033 in. deep. The slot width was**
**where j = I represents the bottom, and j = 32 the top of the****equal tO the boundary,layer****displacement thickness before**
**bleed slot.** **the interaction, and its depth-to-width ratio of 3 is selected****The grid inside the bleed slot consisted of (34 x 32) mesh****based on the experimental results of the optimization study**

**points in the streamwise and normal direction, respectively,****by Syberg and KOncsek.: The slot was positioned at three** **_'**
**Stretching was used in the streamwise direction, in order to** **different locations, upstream, downstream, and across the**

**Cluster the grid points inside, and near.the slot as follows:** **shock impingement point. For across the shock bleed, the slot**
**center was positioned directly at the shock impingement point**

**with the fiat platesurface****(X., = I.% in.). The downstr_'am**

**AX, = 0.03***i _ I _ 64,* **! + 63 _ i****(5)** **bleed Case was chosen such that the centerline of the bleed****slot is at the location of the maximum computed surface shear**
**AX, = !.5625 x 10 -_****I - 20 _: i ": ! - 13****stress in the separated flow case without bleed (x = 2.167**

* i + 13 s i _ i + 20* (6)

**in:). The upstream bleed location was similarly selected at**_{the opposite side relative to the shock impingement point with}**the centerline at x -- 1.753 in. from the leading edge. The****=** **-** **slot base pressure was maintained at the same value (0.42 of***AX,* **I. 125AX,,,*** I -_ 21 ="i =- I* 63

**(7)**

**preshockpressure), which resulted in bleed mass rates of 3.42,****I + 12 > i _" I + 1****4.65, and 5.05-% of the upstream boundary-layer mass flow**

**for upstream, acrosS,and downstreambleed cases,respee.**

**=** **tively. Someof the computedresultsfor downstreambleed•**

**AX,****1.125AX,,****i - 12 s i < I****(8)** **¢onfguration were reported earlier. '" Here, the results of the**

**I + 21 _ i "_I + 62****flowfield computations in the Shock/boundary-layer/bleed **

**in-teraction zone are presented for the upstream and across the****where i = I represents the grid at the center of the bleed****shock bleed. The computed results are compared for the three**

44 **HA%11!|)._%|}11.11%1{,** **'_11_)(Kl..X%ll.%%Hit()I%!:ARYI...%_I.I_****I,%II'RA(-iI()%_**
i !
**Level p**
**I.** **140O**
**K** **1.471**
**J** **1,44a**
I **t .413**
**H** **1.304**
**0** **1.366 .**
**F** **I .i2il**
**E** **t .SO7**
**O** **t 26S****C** **1239**
**il** **1.210**
**O** **I .IS2**
7 **I .Og4**
6 **I O60**
**4** **1.O0? •**
**3** **0.070**
**2** **0.g49**
**1** **O.O20**
**Fig. 2** **Presaure contours for the no-bk,cd case**

**,, '"" _-**

**,, '"" _-**

**_**

**_. o_o**

**_. o_o**

### ,,=

**,,o**

***=o**

**,=o**

**- ...**

**- ...**

### _

### ...

**...**

### ...

**".:**

### ...

### ";...

**.::**

**P,/P 1.4**

*/*

*/*

- **1.0**

**°'°0;6_'**

**'' ""_**

### ...

**,.oo**

**_.5o**

**'2'.6o**

**x/x,**

**Fig. 3** **Comparison o1'surt'eL'epremmre dbtflbution for the dlffereut**

**bleed configurations.** **Fig. 4** **Premtre contours for upstmm****bleed,**

**Figure2 showsthepressure****distdbutlonneartheinteraction** **1.36).** **As for the staticpressuredistributiondownstreamof**

**:** **zone for the no bleedcase.The incidentshockand the sep-****the bleedslot. there is an abrupt pressuredrop for a short**

**,** **arationandreattachmen(shocksares.'enin this figure. Figure****distancefollowedby a gradualpressurerise in the upstream**

_ **3 showsthe plate surfacepressuredistributionof the three****bleedcase.However, in thedownstreambleedcase,the static**

**bleed casesand for no bleed. The wall pressuredistribution****pressureoverthe platesurfacedropsdownstreamof the bleed****showsa significantreductionin the lengthof the interaction****slot,whereasin the acrossthe shockbleedcasethe pressure**

**regioncomparedto the nonbieedcase,and an eliminationof****risesfirst, then dropsslightly.**

**the pressureplateauin all three bleedconfigurations.Fur-****Onecan seethatin boththeupstreamand acrosstheshock****thermore,thepressureratiodownstreamis slightlyincreased****bleedcases,thepressurestartstodrop beforetheslotopening****over the nonbleedinteractioncase.These observations****agree****and reachesa value of pip, ... 0.8 at the intersectionof the****with previousreportson the effectof bleed, as discussed****by****fiat plate with the upstreamslot wall. in the case of **

**down-Hamed and Shang.' Figure3 clearlyshowsthat there isa big****streambleed, the pressuleinitially buildsup on the plate****differencein the staticpressure,at thecomer of the fiat plate****surfaceupstreamof theslotope_in8, reachinga valueslightly****surfaceand thedownstreamslotwallfor the threebleedcases,****higherthan that of the plateaupressurein the caseof ****sepa-Thispressureis lowest(pip, = 1.22)for the upstreambleed****rated flow without bleed(pip, ~ !.2), followed by a very**

**case.and highest(pip, =. !.5) for thedownstreambleedcase****sharpdropto 0.8 at theupstreamslotwall comer. In all three****with the acrossthe shockpressurevalue in between(pip, =****cases,there isan initialmoderatepressuredropover the first**

### lo

_i., Ir¸

*'i.* . o , _ **IIAMI-|J '_NDJl.ll_l(i****MltJ( K I AMI_.-_R|fl)I.%DARY I AYF_R|%II-RAI ll(J_5****4.5**

### if

*"*

### I

**part of the sk)t opening folh)wed by a 5harp rise across a shuck**

**emanatin8 i_tsid¢ the slot as sh¢)wn for the upstream bleed** ...

i * pressure contours of Fig, 4.* "...

* The Math number contours are presetlted JnFigS. 5-7. The* ...

i **contours indicate a choked flow in all three hh:ed cases. The****.,,ub._t)nicboundaty-la,ver fk)w entering the bleed .slot initially****accelerate.,+due to the ,;eparation babble** at **the upstream wall**

i _ **o[** **the** **blued slot that acts as a _onvcrging-type ¢()t_.striction..**

**After passing through the convergent section of the constric-** **"...**

**-'** **tiOn. the n6w choked flow goes through a brief expansion**

**region where the flow is further** **accelerated. The fiL+wthen**
**decelerates toward._ the slot exit as it reaches an effectively**
**Constant area dov,'nstream of the separation bubble.**

**The velocity distributions across the slot opening are shown**

* in Figs. 8- lO. Generally the normal velodty component in-* z+

**_:**:i **creases gradually****v/U_ ~ -0.3****somewhere.cross the slot opening _ind reaches a plateauin the downstream** **half of the bleed**

-ii *I'* **slot. with a slight inCreaSe further** **near the downstream** **slot**
i **_all** **in the two cases****of** **acre:ass the shock** **and downstream**

**Fig. ?** **Mach numbercontoursfor downstreamble_d.**

### i

**:::**

**1.o**

**(_-_,31D'=o**

**(_-_,31D'=o**

### i

" "...*" ...*

**0.8**_

**u/U***... •...*

**(Streamwhl*)***, , • ...*

**..: / / ,':," ... :.:::"'"****::::::::::::::::::::::::::::::::**

**::::::::::::::::::::::::::::::::**

### ...

**o.6**

## I

"!## '

## ,I

**" 0,2**

**°_o.o**

**l!lil**

**-°";**

**Fig. $****Math numbercontoursfor upstreambl_d.** **-0.14£ ,.,...nl..._4** **1,095** **1.097** **1.098,...1.100** **1,101,** **1.103I_1**
**X/X_**

**FIB.8** **Velocity distribution across slot openln| for upstream bked.**

**• °°°** **°"°**°'°°.._o** **.... °*°°*,°._**
' **0,4**
i
*:'* **0.2**
**-0,0**
i
**: _** **-0.2**
', **-0.4** **i....,.,,ah,.,,,.h;,,,,_****...;.,...n..i...,_,.,."****, _:** **0.$ =** **0,998** **0.990** **0,999** **1._1.** **1.002** **1,_04**
*'_.",'* **X/Xm**

**,',!'.****Fi|. 9** **YdodO' dbtHbutioe_ro_ slot ol_nlq for _¢ro_ the sh_lt**

*_,_,,* **Fill. 6** **Ma_h numbercoetoursfor scrotatl_ sh_k bleed,** **bk_d.**

**(Y-Y_/O',,O****,r x/x,#-1 2****1.0**

**OGWNST'REAMBLE[O**

**_"*** **./U****(Streomwlx)** **ILO** _ **_PSTREAMBLEED**

**(.Normol|** _ **ACROSS-SHOCKBLEED** **'**

**O.I** **(_soJuf,)****7.0**
**0.8-1****_114** **__/_** **6.o**
**0,2** **"" "3.0****'O'O** **O0°**
... **2.0**
**-0,2** _ **•**
**lo**... **' '_'_o**
0.894 0.896 **0.897** **0.899** **0.900** **0.902** **0.903** **a)** . **u/U****X/X,,****ATX/X_-I.3**

**Fig. I0****Veh_ty dislribution across slot openingfor downstreambleed.**

* 8.0 -a* _

**OOWNSTRFJ_****BLEE'D**

**uPSTRF.AM****BLEED**

**M,,,2.0.Re-2.9Be5,beto-32.5BS"****7.0.'**

**B4.z4_****ACROSS-SHQ._I_,I.E.ED**

**DOWNSTREAMBLEED**

**6.0**

**UPSTREN_I****BLEED..****0.004**m

**AcRoss-S.OcK**

*e_*

**sEp,_t_w/oe_o****_ _.o**

**0.003_**

**<_. 4.0****0.002**

**3.0**

## o

**oo**

0.000 1.0 *_*

**-0.001**_

**0.0**

_{000}

_{020}

_{0 40}

_{0 _0}

_{0 SO}

**,, .'. ,,**

_{1O0}**".**

**-0.002**

**b)**

**u/U***• .:_*

**Fig. 12 Comparisonof the velocityprofilesdownstreamof the **

**in-i in-i in-i'1 in-i in-i t in-i in-i I**

**-0.00_.I __v.... '"0'._6****...1.00 ....** **1.50** **'2'._0** **teractio_ zonefor the differentbleed¢onflgurat!om.**

* x/x_* .

**.**.

**",**

**e_NN_****SEP/_A'I'EO****w/o BLeD**

**UPSTRF_.I****BLEED** "_

**-** **Fig. I !** **Comp_****ofthe skin friction coefficients****for the different**_{t.t4.t'#}_{OOWNSTRI_}_{BLEED}

**bleedconfigurations,** *
*

**2.o-bleed, On the other hand, the streamwise velocity component** *:"*

**reaches a local ulU_ Of 0.5-0.6****upstream of the slot shock,** **_.s**

**then** drops linearly reaching **slightly negative values (-,0.02** _,

**to -0.1)****near the downstream****slot corner. Typically,*** in the* _

**computations** **of flowfields** **involving** **bleed, the bleed** **mass** '_ **_.o**

**flux is specified****while the tangential****velocity is set equal** **to**

**zero across the bleed zone. The results of Figs. 8-; 10 suggest**

**that the neglect of the streamwise** **velocity component** **in the**

**bleed zone of shock wavelboundary.layer****interaction can con-****0.s**

**stitute a serious source of error in the computations.****This**

**might be a major cause of discrepanciesbetween _he corn,**

**puted and expeflmental****results downstream of the imeracti0n**

**bleed zone in supersonic inlets/-_****o.o ,,,, ... ... , ...****_.**

**Figure 11 presentsthe computed skin friction distribution****o.,o****o_o** **oao** **o_0** *__/* **__0** **__o**

**over the fiat plate surface for the three bleed locations and** **x/x,_**

**for the no bleed separated** **flow case. The reduction in the****FIR.**t3 **Com_rbon of Rparetlon t'qO_ for the different bleed cos.**

**length of the interaction zone due to__bleed is clear in this****II_r_flom,**

- • * s,qr.-r,iClL_U* ...

**I....**_

**__.,_**

**J...**_ ... _

**-**

**t ...**

**,** **,** **llAML-I)** **ANI) t.l".ttNl(L****MH)( K L.,AMINAR B()L NI)ARY-I.AYER** **IN1ERACI I()N._***
*

4']-i **"** **eteEo** **strongConservatiOnlawform.,The investigationw_s.restricted**

**L** **L --** **[.__._,****tC_OeS.,Se,****OCKetmLI** **tO laminar flOWstO avoid the uncertaintiesassociatedWith**

**the normalbleed slot,and computationalgrid wasClustered**

*-_:* **nearth©surfaces,****Threebleedlocations****upstream,****across,**

L **"...** **and downstreamof the shock impingementpoint were **

**in-,,** **i** " I **vestigated for the ,q'ameslot size and Static pressure _it the**
[, _ _ ..._{=} **__'___._'.__.. _{'__}**

**bottomofthebleedport,**_{andM ach num ber throughout the 'nteractionre glen and in-}**Resultswerepresentedforpressure**

l **-J/+****,_** **side the bleed pOrt. and for the Surface pressure and skin*** ,)P"* i I

*° I*

**friction distribution. ACcording to the computed results, the***pro-... ¿*

**across-shock bleed proved to be the most effective in****[**_

**venting separation and shortening the interaction length,****°o**

**us**1

**,_**_

**whereaS the upstream bleed slot proved to be the least**

**ef-fective. The results indicate that the downstream bleed slot****x_,** **location produced the most favorable velocity profiles and**

**Fill. 14 Comparisonof the boundary-layerdisplacementthickness** **skin friCtionrecovery downstream of the interaction region,****,. !**
**for the differentbleed.configurations,****as well as the maximum reduction in boundary-layer **

**mo-mentum and displacement thickness. The results suggest that****a combination of across-shock and downstream bleed slots****'_"** i **f'. • Noe_Eo** I * might provide the two advantages, namely no flow separation*
:

**"**

**, -**

**].-.--UPST_OU_eC_EO****|**

*§*

**in the interaction region and fuller boundary-layer profiles****'**

**/.-.-, ACaeSS.SV_r_eCEn**

**downstream of the interaction zone.****_ __** **'-2----..** * /[_][ ...* __.

**Acknowledgments**

* /j* ...

**,**

**• ,**

**•**

**Contract NASA NAG3-1213. The computational work was**

**performed on the Cray Y-MPI28 Of Ohio Supercomputer,**

**Columbus, Ohio.**I I

**0** **0.s.** _ _.5 2 **'Hamed.A., and Shang,J., "'SurveyandAssessmentof the Val,****idationData Base forShockWave BoundaryLayerlnt,2,raCtionsin**
**SupersonicInletS,"AIAA Paper 89-2939.July 1989.**

**Fig. 15 Comparisonofthe boundary'layermomentumthicknessfor****:Syberg.J., and Koncsek.J. L., "Bleed SystemDesignTechnology** !_
**-** **the different.bleedconfigurations,** * for SupersonicInlets." AIAA Paper72-1138.Nov./Dec. 1972.* _

**'_Fukuda.*** M. K., Hingst.W. R., andReshotko,E.. "'BleedEffects* ;_

**on****Shock/Boundary-Layer****InteractionsinSupersonicMixed Com..** :
**figure for all three cases. However, a small flow separation****pressionInlets."JournalOf Aircraft, VOI.14.No. 2. 1977,pp, **

**151-zone as indicated by the negative skin friction coefficient can****156.** _.
**be observed for the upstream and downstream bleed cases,** **_Hamed,A.. "'FlOwSeparationin Shock Wave-BoundayLayer**

**btR not for across the shock bleed. The friction coefficients** **Interactionsat HypersonicSpeeds," NASA CR 4274,Feb, 1990.**

**are higher for all three bleed cases downstream Of the inter-** **_Martin,A. W., Koslin,L. C., and Sidney, D, M.. "Dynamic*****"**
**action zone in comparison to the no bleed friction, indicating** **Distortionatthe Exitof a SubsonicDiffuserof a MixedCompression _{Inlet."}_{NASA}_{C-R-1644.Dec. 1970_}**

_{i"}

**fuller velocity profiles. The highest friction coefficient value**

**"Knight,D, D.. "ImprovedCalculationof HighSpeedInlet Flows.****downstream of the interaction is for the downstream bleed,*** PartI: NumericalAlgorithm,"AIAA Journal.Vol. 19,No. !. 1981,* "

**and the Iowcst for the upstream bleed. These differences in**

**pp.M-41; alsosee "PartII: Results," AIAA Journal, Vol. 19,No.****the velocity profiles appear to persist for a long distance down.** * 2, 1981,pp. 172-179.* :_

**stream of the interaction as can be seen in the velocity profiles**

*I*

**'Weir,L.J.. Reddy,O. R., and Rupp,G_ D.. "'Mach5 InletCFD****of Fig. 12.**

**and ExperimentalResults."AIAA Paper89-2355,July 1989.**

**Figure 13 compares the extent of the separation regions as** * 'Carter.T. D,, andSpong.E. D., "'HighSpeedInletInvestigation.* i

**determined from u = 0. One can observe that the separation****Vol. I Description**

**of Programand Results;Vol. IIData Summary,"****_'**

**bubble height is reduced to 32 and 25% of its value without****Air Force FlightDynamicsLab.. AFTDL_TR,77-105.**

_{tersonAFB.OH, Nov. 1977.}**Wright,Pat.**

**bleed for the cases of upstream and downstream bleeds, re-** **_Strike.W.T.. and Rippy,J., "'Influenceof Suctionon the Inter-** i
**spectively. Across the shock bleed completely eliminates sop-****actionof an ObliqueShock with a TurbulentBoundaryLayer at** i
**aration as indicated by the skin friction results of Figs, 11 and** **Mach3," Arnold **

**EngineeringDevelopmentCenter,AEDC-TN-61-12. The boundary layer's displacement and momentum thick-** **129,Tullahoma."IN, Oct. 1961.**

**ness are presented for the three bleed locations and for no** **""Seebaugh,****W., andChilds,M.. "ConicalShockWaveBoundary-** !
**bleed**in**FigS. 14 and 15, One can see that the largest reduction** * Layer InteractionIncludingSuction Effects," Journal of Aircraft,* i

**in _* and e are re/*lizedin the downstream bleed case and the***_*

**Vol. 7. No. 4, 1970,pp. 334,340.****"Benhachmi,O., Oreber, l., and Hingst, W., "Experimental****least reduction for upstream bleed,** **and NumericalInvestigationof an ObliqueSbock-Wave/Turbulent**

**BoundaryLayerInteractionwithContinuousSaction.'_AIAA Paper**

**Conclusions****89.o35?.**Jan.**1989.**

**•:Gubbison.R. W.. Meleason.E. T., andJohnson.D. F.. **
**"'Per-A numerical investigation was conducted to determine the** **fortunateCharacteristicsfromMach2.58 to !,98of an Axisymmetrtc**
**effect of bleed location on the flow in an oblique shock/bound-****MixedCompressionInlet Systemwith60 ****PercentInternalContraC-ary-layer interaction. The implicit factored scheme of Beam** **tion." NASATMX-1739,Feb. 1969.**

**and Warmingts was used to obtain numerical solutions of the*****_Fukuda.M, g., Hlnlpt,W. O., and Reshotko,E.. "Controlof**

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, 4_- **IIAMI:I}-.%%l}I I:IINI{__II()CK I,AMIN:._Rll(}t%I)%KY i.A'_IRI%11_R._(IIO.%_**
**Shc'_ck****B_undury L..L',_r****Interactions****h_ Bl_cd in Mixed C'omprcSsion •****Vul.'4.No. 4, Iq86.pp_ ._9_-h(}6_**

**Inlets.'"NASACR :._95.1975.****"Vishal,M, R.. "('altulalmnof Vi.w0us****Transonic****RowsAblaut**

**"Wong. W. F.. "'T:hc Application of Btmndary La,ytr Suction to****a Sup,:t_;rltiC',l Airfoil."****Air** **[_orce Wt_tsht Aeronautical****Lal'_..**

SupprCss**StrongSh0_k.lnduced****Stpara,ti0n m Sul_rs¢_nicInlets."** **AFV,'AL.TR._,3(II3.Wr|ght-PattctsonAFB. OH. July****19Xb.**

**AIAA** **Paper 74-111_3. O_t; 1974.****'"llamcd,****A,, and Lchnig, T.. "An Invtstig, ation ,)I' Ohl!quc Shock,'**

**':Bc;,m.****R., and Warming, R,, "An ImpliCit Factored SfJhtm¢ fi)r****Boundaq, Layer Interaction,"** *JoUrna/c_l'Pr.pul._:i_m* **and Power. VOI ...**

**the Conlprcssihl¢** **N.'ivicr.Stokcs** **Equations,"****AL4A Jcs.tnal.****Vol.** **[6.** **X. No, 2.1_192. pp. 418-424.**

**No. 4. I,J7_l. pp. 393-4(12.****';'ttakkincn.****R, J.. Grcher,** **l., Trilling.,** **L,. and Al',:rhanel,****8. S..**

**"Vi.,,hal. M.. and Shanty. J.. "'Comp;,rativc****Study Between** **Two****'"_c** **Interaction of an Oblique Shock Wa,;'c with a Laminar B.und.**

**N;,,,,scr-Stokcs** **All_orithms for Transonic** **Airfoils,"** **.:U,4A***J.urnal,* **ar.v La)_r."****NASA** **Memo ..18.5,',iW.** **March I959.**

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**t**

**JOUR,NAL OF PROPULSION** **AND** **POWER**

**Vol,I0,No. I,Jan,_-Feb.1994** f

**Investigation of Shock/Turbulent Boundary-Layer**

**Investigation of Shock/Turbulent Boundary-Layer**

**Bleed Interactions**

**A. Hamed,*** **S. Shih,? and J. J. Yeuan?**

*University of Cincinnati,* *Cincinnati,* *Ohio 45221*

**A nu_nericalinvsstig8tionwas conductedto determinethe effectof bleedon obliqueshockwave/turbulent****boundary-layerinteractions(SWBLI).The numericalsolutionsto the compresaibleNovler-Stokesequations**
**revealthe flowdetailsthroughoutthe interactionzoneandinsidethe normalbleedslot. Resultsore presented**
**for an incidentobliqueshock of sufficientstrengthto causeboundary-layerseparationon a flat plate in the**
**absenceof bleedat • fresstreamMachnumberof 2.96andReynoldsnumberof 1.2 x 107/it,with bleedapplied****acrmsthe shockimpingementlocationovera rangeof bleedmassflowratescorrespondingto differentvalues**
**of plenumpreuures. The resultsindicate a complexflowstructurewith 18rilevariationsin both the norrmd**
**and tangenthdflow velocitiesacrossthe bleedslot. The flow entrainmentinto the slit is accompaniedby an****expanelon.enmpressionwave systemwith a bow shockoriginatinllinsidethe bleedslot. Incres_._ the bleed**

**rnsmflowbydeerensinlithe plenumpreseurecausedan in/thddecrease,then a later Increasein****boundary-layermomentumanddisplacementthicknesedownstreamof the interaction.**

**Introduction** **terms of removing flow separation, shortening the interaction**

**THEinteractions can be accomplished through flow suctioncontrol of flow separation in shock boundary-layer** **length, increasing the pressure gradient, and producing fullervelocity profiles downstream of the interaction. Lee and**
**(bleed) in the interaction zone. In the case of mixed compres-** **Leblance presented their experimental results from taps, **
**schli-sion supersonic inlets, the bleed system design is critical tO** **eren, pitot, and static probes for two levels of suction applied**
**the efficient and stable operation of the system. Hamed and** **through porous wall sections across the shock impingement**
**Shangt reviewed the existing experimental data for shock wave** **point. The poor performance of the weak suction was **
**attrib-boundary-layer interactions in supersonic inlets and other re-** **uted to the effects of surface roughness.**

**latedconflgnrations. According to this survey, there is enough** **Fukuda et al.7 determined experimentally the change in**

**experimental evidence2-7 to indicate that local bleed can con-.****boundary-layer characteristics across oblique shock wave in-** _
**trol flow separation in shock wave/boundary-layer interne-****teractions with bleed over the centerbody and cowl of a **

**super-tions. There are disagreements, t however, among the differ-** **sonic inlet. This study was conducted at different bleed mass**
**ent experimental results regarding the effects of bleed location** **flow rates, bleed hole sizes, bleed locations relative to the**
**relative to the shock2"'7 and of bleed hole size.7.s** **shock,and bleed hole inclination relative to the surface. Based**
**Strike and Rippy2obtained surface pressure measurements** **on the change in boundary,layer displacement and **

**momen-with porous bleed applied across and upstream of the shock** **turn thicknesses, and in the transformed form factor for the** *_:_*
**impingement. Based on the minimum mass flow required for** **different bleed configurations, they concluded that bleeding** • f_u
**the static pressure downstream of the interaction to reach the** **upstream and downstream of the interaction was preferable** **_''_i**
**theoretical pressure ratio, they determined that less suction .****to bleeding across the shock. These results were unchanged** 4
**is requiredwhen applied upstream. Seebough and Childs3who** **by the normal bleed hole size which was found to have a**

**conductedtheir oblique shock wave boundary-layerbleed study** **negligible effect on the results.**

**over the inner surface of a cylinder, with a cone as a shock** **Most viscous flow computations in supersonic inlets v-ts re-** **: ;**
**generator, concluded that across the shock bleed was more** **quire some knowledge of bleed flow rates and/or pressure**

**effective in controlling boundary-layer separation. I-Iingstand** **distributionin the bleed regions. Comparisons of internal flow**

**Tanji4 and Benhachmi et al.s used pressure taps to measure** **computational results with the experimental measurements in**
**i-the surface pressure, and hot wire to measure i-the bleed mass****supersonic inlets revealed reasonable agreement between the** ! '
**flow distribution through nozmal holes in SWBLI. Their re-** **computed and measured surface .pressuresupstream of the** i_i
**suits indicated that the bleed mass flow distribution followed****ramp bleed. However, discrepanc|es in the predicted shock**

**the surfacepressure distribution. In addition, Hingst andTangi 4** **locations and velocity profiles downstream of shock bound,**
**used pitot probe surveys and surface flow visualization to** **ary-layer interactions with bleed suggest deficiencies in the**
**compare the performance of bleed locations upstream, across,** **bleed modeling. Other investigators actually solved the flow**
**and downstream the shock. According to this study, across** **throughthe boundary layer and into the bleed slot. providing**
**the shock and downstream bleed produced similar results in** **insight into the bleed flow region, te.t' This. approach **
**elimi-nates the need for experimentally deriveo meea mooeJs mr****supersonic inlet flow simulations, but can be very costly **
**com-putationally.**

**Presentedas Paper92-3085at the AIAA/SAE/ASME/ASEE28th****Recently, some research efforts have been directed at **

**ira-JointPropulsionConference,Nashville,TN, July6-8,****1992; received** **proving bleed models. Paynter et at.to used the rough wall**

**Aug. 20, 1992;revisionreceived April 5, 1993;acceptedfor publi-****algebraicturbulence model of Cebeci and Chang_ to simulate**
**cation April29, 1993.Copyright• 1993by trteautnon. Published****the overall effect of bleed on the growth of the boundary**
**bytheAmericanInstituteofAeronauticsand Astronautics,Inc., with****layer. The proper values of the roughness parameters were**
**permission.**

**• Professor,Depirtmentof AerospaceEngineeringand Engineer,** **determined through matching the computational and test re- _{suits for near wall velocity distributions downstream of the}**

**ins Mechanics.FellowAIAA.**

**• Departmentof Aerospace Engineeringand Engineedn| Me-** **bleed band for seven bleed configurations, with shock ****bound-chanica.StudentMemberAIAA.** **ary-layer interactions in some cases. The results of this **

### in-le

**'** **'** **80** **HAMED. SHIH. ANI) YE[' _N:****INVE._T1EIA1'ION OF BLEED IN'I=ERAL_IONS**

**vestigationdemonstratea Strongdependenceof the surface** **(bleed)is appliedthrougha normal slot locatedacrossthe**
**roughnessOn the fraction of the upstreamboundary-layer** **incidentoblique shock on a flat plate turbulent boundary****massflux removed, High roughnessvalues were foundfor****layer,The.regioninsidethe slotfrom the bleedsurfaceto the.**

**bleedratesbetween3_,15% oftheupstream****boundary-layer plenumexit****was includedinthesolution*** domaininOrder*to

**massflux,**

**butwereinsignificant****forlowerand higherbleed**

**realisticallymodel thebleedfl0wand itsvariationwiththe**

**rates.Chokedbleedflowthroughslanted****holes****gavethebest** **plenumpressure.The resultsof theflowcomp_nadonswhh**
**boundary-layerprofileintermsofflowseparatiOnControl.** **differentbleedmassflowratesrevealindetailthevarious**

**Hamed and Lehnig-".-'zconducteda numericalstudyinan** **flow****regimesintheinteraction****regionand withinthebleed**

**incidentOblique****shock/laminar****boundary,layerinteraction,with** **slot.**
**bleedthrough****a normalslot.By obtainingtheflowsolution**

**ina domainthatincluded****theshockboundary-layer****and ex-** **Computatlonal****Details**

**tendedinsidethebleedslot,theywere ableto revealthe** **The PARC** **code_ was usedinthe presentinvestigation**

**variousregimesinthiscomplexfiOwfeld.Theirresults**dem- **afterconductingvalidationstudies****forshockwave/turbulent**

**onstratoda largevariationinboththenormaland tangential boundary-layerinteractions,24withand **
**withoutflowsepa-flowvelocitydistributionacrossthebleedslotopeningatthe** **ration.****The performance****offourdifferentCodeswithdifferent**
**platesurface.A separatedflowregioninsidethebleedslot** **turbulencemodelswasassessedintermsoftheagreementof**

**inthecomputedresultssuggestsa reductionintheflowcoef-** **theirComputedresultswiththeexperimentaldataofRefs.**25

**ficientandtotalpressure.Hamod and Lehnigz_presented**the **and 26.The requiredgridrefnementand computertimeto**
**flowfieldsforthreelocations****ofthe normalbleedslot,**up-**reachthisagreementwerecomparedforincidentshockon a**
**stream,across,and downstreamof theshockimpingement** **flatplate****boundarylayer,****and forflowovera compression**

**point.The resultsdemonstrated**that**foragivenplenumpres-** **comer.The prediction****oftheseparationlength,thesurface**
**sureattheslotexit,theshock-inducedflowseparation**on the **pressurepropagationupstreamOf the interaction,and the**
**plate****was eliminated****intheacrosstheshockbleedconfgu-** **recoveryoftheskinfrictiondownstreamof theinteraction**

**rationand reducedintheupstreamand downstreambleed** **receivedspecialattention.From thefourassessed**codes,the
**cases.****EdwardsandMcRae 2"-****alsocomputedtheflowfieldfor** **two_,_ thatUsetheimplicitapproximatefaetorization**

**tech-an obliqueincident**shock,**on alaminar*** boundarylayer,*with

**niqueofBeam and Warming_ toadvancethesolution,**

**per-bleed through a normal slot across the shock impingement**

**formed best both in terms of computer time and grid**

**inde-point. They compared the computed surface pressure distri-**

**pendence. Visbal's code= was the most robust, required the****butions for a specified uniform normal bleed velocity across**

**least number of time steps to reach convergence, and its**

**corn-the slot to corn-the plenum case, and demonstrated that corn-the first**

**poted results were consistently better than those obtained**

**case underprediCtsthe initial flow expansion into the slot. The**

**_om the other codes with algebraic turbulence model.**

**How-solution domain for the plenum case was similar to that of**

**ever, Awa et al._ proved the two equation k-e model to be**

**Hamed and Lehnig,_°.'1but a uniform suction velocity was****superior to the algebraic models for applications with**

**sepa-specified at the slot exit.**

**rated flOWS.Consequently, the PARC code _ was used in the**

**The discrepancies among the different experimental studies**

**present study because among the uodes with the two equation**

**is an indication of the complexity of the flow in these config-**

**turbulence models, it performed best, in terms of agreement**

t **urations. Based on the comparison of their computational** **with the experimental results and required the least grid **
**re-results with the experimental data of supersonic inlet flow-** **finement to achieve this asreement3 4 In addition, the PARC****fields, Reddy et al. I) stressed the need for a detailed study of** **code was validated3° through comparisons with experimental**
**I** **the effect of the individual bleed ports. Bleed optimization** **data for several flow configurations including supersonic flow**

I **can only be accomplished through a parametric investigation** **over compression with separation, and has been used in sev-** **•**
: **in which the bleed conditions are changed systematically. The** **eral supersonic and hypersonic inlet flow simulations. |a-|4.)|**

**large number of parameters and the difficulties in obtaining** **Centraldifferencingexplicitand implicitdissipation schemes)2***'_*

**accurate flow measurements in the interaction zone precludes** **are used in the PARE code for the solution of the Reynolds-****"<':'****a complete experimental investigation,** **averaged Navier-Stokesequations in strong conservation form.***_ '*

**The purpose of the present study is to conduct a numerical** **The Beam and Warmingfactorization algorithm coupled with** **_.**
**investigation to Characterize the fowfield in oblique shock** **Pulliam's pentadiagonal formulation form the basis of its ira.**

**•-** **wave/turbulent boundary-layer interactions with bleed, and****plicit LU-ADI style solution scheme. The turbulonce model**
**to provide a basic understanding of the bleed flow controlling****used in the PARC code is based on Chien's low Reynolds****mechanisms. In the investigated configuration, flow suction** **number k-e model )) with Nichols J° modifications to add **

**com-...** _ **.**
*.._*
**M " _1.9t** **Ttw • 4-_2OR**
**Re - 1.2 x 107.1it****P_** **- 14.7** **pit**

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**HAMED. _tlIH..&ND****YEt:AN****INVESTIGATION ()F BI.I_ED [NTERAC'I'|ONS**

8l-e

the **pressibility effects. For the simulation, flow was considered** **. around the shock impingement location I ft from the flat plate**
**lary** **to be turbulent throughout the Calculationdomain_ no attempt****leading edgc. 'l"he grid .gpaclng was varied in both x and .v**

**the** **was made to model transition and/or relaminariZation,****directions with clustering around both bleed walls and at the**

**r to** **Referring to Fig. I. the solution domain used in the two-** **plate surface as shown in Fig. 2. The computational results** ...
**the** **dimensional flow simulations extends upstream of the flat** **were obtained with AYm,n.-_ ,3,X=,, "" 0.25794 x 10-' ft.**

**vith** **plate leading edge, downstream Of the shock wave/turbulent*** corresponding to y" = 2.(I at x = 0.9 ft, using a 308/68 grid*
ous

**boundary.layer interaction region, and inside the bleed Sl0t,**

**over the plate surface and a 75/68 grid inside the bleed slot.****eed**

**where the specified plenum pressure at the bottom Controlled**

**based on the grid refinement study results of Ref. 24, The**

**the amount of bleed mass fl0w. The incident oblique shock****computations for a typical bleed case required 5000 local time**

**crosses the upper boundary, all other wave systems including**

**Steps at 0.3 Courant-Friedriehs-Lewy (CFL) number tO reach****the reflected, and any separation and reattaChment shocks,**

**steady-state solution based on six Orders Of magnitude**re-ion

**(:.rossthe outflow boundary. UnifOrm freestream flow con-****ductions in the averaged rms error in the flux.**

ent **ditions are applied at the inflow boundary and all variables**

pa- **were extrapolated at the Outflow boundary. NO slip adiabatic** **Results and Discussion**

ent **flow Conditions are applied at the plate and bleed walls. The****The Computations were performed at the incoming flow**

**t of** **static pressure is specified and first order extrapolation****is** * conditions of M,, = 2.96, Re,, = 1,2 x 10_/ft, 7",,, = 437"R*
• 25

**applied for the rest of the flow variables at the bottom of the**

**and P,,, = 54.7 psi, and an impinging oblique shock angle Of****:to**

**bleed slot. The location of the incident shock ts fixed at the**

*con-n a*

**25.84 deg. These are the same as the experimental test**

**upper boundary with freestream and postshock conditions****ditions of Law = for the separated flow case at a deflection**ion

**specified ups.tream.and.downStream.****The slot was centered**

**angle 8 of 7.93 deg. In his experimental study, Law used oil****ace**

**the**ion the

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• **** **EXP.** **DATA (LAW, 1974)** **,,o** *****.*** **EXP.** **DATA** * (LAW,* 1974)

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