Scramjet Propulsion

Edited byE.T. CurranDepartment of the Air ForceDayton, OHS.N.B. MurthyPurdue UniversityWest Lafayette, IN

Volume 189PROGRESS INASTRONAUTICS AND AERONAUTICS

Paul Zarchan, Editor-in-ChiefCharles Stark Draper Laboratory, Inc.Cambridge, Massachusetts

Published by theAmerican Institute of Aeronautics and Astronautics, Inc.1801 Alexander Bell Drive, Reston, Virginia 20191-4344

Contents

Preface xxiIntroduction xxiiiI. International Efforts xxiii

II. Inlets, Combustors, and Fuels xxivIII. Overall Systems xxivIV. Future Developments xxvV. Closing Comments xxv

References xxvi

Chapter 1 Scramjet Testing in the T3 and T4 Hypersonic ImpulseFacilities 1

Nomenclature 1I. History, Aims, and Developments 2

II. Facility and Instrumentation 5III. Fuel-Injection Systems 6

A. Wall-Injection Combustion Results 8B. Wall-Injection Film-Cooling Results 10C. Port-Injection Results 11D. Central Injection 13

IV. Combustion/Mixing Processes 17A. Mixing Controlled Combustion 18B. Kinetically Controlled Combustion . . . ~. • 18C. - Shock-Induced Ignition 19D. Shock-Induced Mixing 20

V. Simple Theoretical Combustor and Thrust Model 21VI. Experimental Results of Specific Impulse •• 25

VII. Effects of Atomic Oxygen and Nitric Oxide in the Freestream . . 30VIII. Different Fuels 32

A. Hydrocarbon Fuels 32B. Silane-Enriched Fuels 34

IX. Integrated Scramjet Measurements 35X. Skin-Friction Measurements 40

XL Discussion and Review 42Acknowledgments 43Bibliography 43

Chapter 2 Scramjet Developments in France 47I. Historical Overview 47

II. Basic Research on Diffusion Flame Combustion (1962-1967) . . 49

vii

viii CONTENTS

A. Combustion in a Cylindrical Duct 49B. FreejetTest 55C. Combustion in a Divergent Duct 56D. Synthesis 59

III. ESOPE Program (1966-1973) . 5 9A. Origin and Principal Aims 59B. Studies Results 63C. Synthesis 80

IV. Studies on Shock-Induced Combustion 81A. Principle 81B. ENSMA and LATECAM Studies 82

V. Prepha Program (1992-1997) 84A. Origin and Principal Aims 84B. System Studies 85C. Development of New Test Facilities 88D. Numerical Means 90E. Development of Scramjet Components 93F. Materials and Cooled Structures 101G. Flight Testing 101

VI. Perspectives 103A. Space Application 106B. Missile Application 109References 112

Chapter 3 Scramjet Investigations Within the GermanHypersonics Technology Program (1993-1996) 119

I. German Hypersonics Technology Program andScramjet-Related Activities -.--... 119A. German Hypersonics Technology Program 119B. Scramjet Related Activities Within the HTP 120

II. Theoretical Investigations for Scramjet Intake Designs . . . . . . 121A. Activities at Dasa-MT633 \. . . . . . 121B. Activities at RWTH Aachen 131

III. Theoretical and Experimental Investigations ofScramjet Combustion at TsAGI and DLR Lampoldshausen . 137

A. Combustor Model Design 137B. Fuel-Injection Modules 140C. Test Results 140

IV. Freejet Wind-tunnel Testing of ScramjetPropulsion Systems at TsAGI 144

A. Scramjet Propulsion System Model Concept 144B. Testing Focus 145C. Test Results 145

V. Considerations for Flight Testing Small-Scale ScramjetModules Using the RADUGA-D2 Flying Testbed . . . . . . 149

A. Objectives for Flight Testing 149

CONTENTS ix

B. RADUGA-D2 Flying Testbed 149C. Flight Test Trajectory and Integration of Scramjet in the

RADUGA-D2 150References 158

Chapter 4 Scramjet Engine Research at the National AerospaceLaboratory in Japan 159

Nomenclature 159I. Introduction 160

II. Engine Model 161A. Inlet 164B. Struts and Ramps 164C. Isolator, Fuel Injector, and Combustor 165D. Combustor Downstream Section and Nozzle 169E. LH2-Cooled Model 170

III. Test Facility 170A. Outline 170B. Components 172C. Calibration of the RJTF 174

IV. Measurements 177A. General Features 177B. Engine Exit Survey 178

V. 5 Test Results 179A. General Features of the Engine Operation 179B. Mach4Tests 187C. Mach 6 Tests 191D. Mach 8 Tests 199E. Liquid-Hydrogen-Cooled Engine Tests 202

VI. Supplementary Studies for Engine Testing . :-.- 203A.1 Computational Fluid Dynamics 203B. Chemical Quenching in Gas-Sampling Probes 206C. Subscale Wind-Tunnel Testing 209D. Reaction Kinetic Studies on the Scramjet •; . . . . 212

VII. Conclusions and Future Prospects 214Acknowledgments . 215References 215

C h a p t e r 5 S c r a m j e t R e s e a r c h a n d D e v e l o p m e n t i n R u s s i a . . . . . . 2 2 3I. Introduction . 223

II. Initial Stage of Scramjet Investigations (1957-1972) 226III. Scramjet Investigations in 1972-1996 235

A. TsAGI Investigations 235B. CIAM Investigations 246C. ITAM Investigations 252D. MAI Investigations 256

IV. Short Remarks on Scramjet Inlet and Nozzle Developments . . . 262

CONTENTS

V. Conclusion 268Bibliography 269Appendix A: Three Problems in Supersonic Combustion 284A.I. Retardation of Heat Release in Supersonic

Diverging-Area Combustor 284A. Introduction ". 284B. Formulation 284C. Results 287D. Qualitative Analysis of Results 293E. Conclusions 294References 295A.II. Combustion Stabilization in Supersonic Flow

Using Free Recirculating Bubble 296A. Introduction 296B. Estimation of Minimum Dimension of Recirculating

Bubble Needed for Self-Ignition and CombustionStabilization 296

C. Scheme of the Experiment: Facility and Tests Conditions . . . 297D. Experimental Model 298E. Tests Methodology and Measurements 301F. Experimental Results 302G. Conclusions 308Acknowledgements 309References 309A.III. The Enhancement of Liquid Hydrocarbon Supersonic

Combustion Using Effervescent Sprays and Injectors withNoncircular Nozzles 310

A. Introduction 310B. Experimental Facility: Test Methodology 310C. Test Results :•: 315D. Conclusions < . . . 319Acknowledgments 320References • 320Appendix B: Deceleration of Supersonic Flows in Smoothly

Diverging-Area Rectangular Ducts 321Bibliography 337Appendix C: Some Aspects of Scramjet-Vehicle Integration . . . 337References 353Appendix D: Leading-Edge Bluntness Effect on Performance

of Hypersonic Two-Dimensional Air Intakes 353Introduction 353Isolated Two-Dimensional Intake 355Underwriting Intake . 360References 367

CONTENTS xi

Chapter 6 Scramjet Performance 369Introduction 369Cycle Considerations 373Flow Nonuniformity and Cycle Performance 375Inlet 377Sidewall Compression Concepts 377Interactive Inlet Design 381Inlet/Isolator Interactions 382Combustor 386Hypersonic Combustion Physics 387Simulation Requirements 388Experimental Simulation 390Comparison of Combustion Data 396Instrumentation/Measurement Requirements 400Computational Simulation 403Computational Methods 404Combustor Performance Index—Thrust Potential 409Nozzle 412Engine/Vehicle System Integration 414Forebody/Inlet 414Nozzle/Afterbody 415Concluding Remarks 418Appendix A: Central Institute of Aviatian Motors

NASA MACH 6.5 Scramjet Flight Test 419Introduction 419Experimental Apparatus and Test Conditions 420Flight and Ground-Test Results 420Appendix B: NASA'S Hyper-X Program 424Introduction 424Flight-Test Vehicle Design and Fabrication . . . ' . - - . 425Flight-Test Plans 429Hyper-X Technology 431Acknowledgments ,. . . . 439References • • • • 439

Chapter 7 Scramjet Inlets 447Nomenclature 447

I. Introduction 449II. Definitions of Performance Parameters 451

III. Inlet Design Issues 462A. Starting and Contraction Limits 462B. High-Temperature Effects 466C. Blunt Leading-Edge Effects 470D. Viscous Phenomena 477E. Boundary-Layer Separation 483F. Isolators/Supersonic Diffusers 489

xii CONTENTS

G. Combustor Entrance Profiles 489IV. Engine Cycle Calculations 489V. Performance Measurement Techniques 492

VI. Design and Performance of Scramjet Inlets 495A. Two-Dimensional Planar Designs 495B. Two-Dimensional Axisymmetric Designs 498C. Three-Dimensional Inlet Designs 499D. Performance Characteristics 500

VII. Summary and Recommendations for Future Investigations . . . 502References 504

Chapter 8 Supersonic Flow Combustors 513Nomenclature 513I. Introduction 514

II. Phenomenological Considerations 517A. Inlet Flow 517B. Combustor Flow 521

III. Design Approach Implications 527A. Step Combustors 527B. Isolator Combustors 535

IV. Fuel Injection Basics 539A. Wall Jets 541B. In-Stream Injectors 545C. Hypermixers 547D. Mixing 548

V. High Mach Number Implications 550A. Mixing 552B. Combustor Reactions 554C. CFD Solution Results =....: 555D. Design Philosophy 561Appendix A: Inlet One-Dimensional Continuity and

Energy Flow Solution 564Appendix B: Profile Flow Solution \ 564Appendix C: Entropy Limit Concept 566Appendix D: Combustor Thrust Potential Concept 566References 567

Chapter 9 Aerothermodynamics of theDual-Mode Combustion System 569

Nomenclature 569I. Introduction 570

II. H-K Diagram 571A. Scramjet and Ramjet H-K Diagrams 573B. H-K Diagram Closure 577

III. Dual-Mode Combustion System 577A. Dual-Mode Concept 577

CONTENTS xiii

B. Ramjet Mode (Subsonic Combustion) 579C. Scramjet Mode (Supersonic Combustion) 579D. Transition from Scramjet to Ramjet Mode 580

IV. One-Dimensional Flow Analysis of the Isolator-Burner System . 582A. Control Volume Analysis of the Isolator 583B. One-Dimensional Flow Analysis of the Burner ' 584C. Establishing a Choked Thermal Throat 5858

V. System Analysis of Isolator-Burner Interaction . 586A. Scramjet with Shock-Free Isolator 587B. Scramjet with Oblique Shock Train 587C. Scramjet with Normal Shock Train 588

VI. Interpretation of Experimental Data 588A. Billig's Experimental Wall-Pressure Measurements 590

VII. Closure 593References 594

Chapter 10 Basic Performance Assessment of Scram Combustors . . 597I. Introduction 597

II. Scram-Combustor Effectiveness 600A. Kinetic Energy Efficiency 601B. Energy Availability Efficiency 604C. Stagnation Pressure Efficiency 606D. Combustion Process 607E. Set of Efficiencies 607

III. Computational Tool and Limitations 609A. One-Dimensional Calculation Scheme 611

IV. General Illustrative Studies 613A. Parametric Studies 613B. Results 615

V. Specific Illustrative Studies 627A. Hypersonic Research Engine 639B. Direct Connect Combustion Tests due to Waltrup

and Billig (1973) \ 648C. NASA Langley Direct-Connect Tests due to Northam,

Greenberg, and Byington (1989) 654D. Free Piston Shock Tunnel Experiments due to Paull (1993). . 657E. Test Data due to (1) Sabel'nikov, Voloschenko, Ostras,

Sermanov, and Walther (1993) and (2) Mescheryakovand Sabel'nikov (1981) '. . . 657

VI. Scaling Performance and Geometry 667A. Approach 670B. Ignition Delay Estimate 672C. Pressure Rise Along Combustor 673

VII. Combustor-Based System Integration 677A. Inlet and Nozzle Efficiency 677B. Inlet Layout 678

xiv CONTENTS

C. Nozzle Layout 679References 679Appendix A: Efficiency Relations 680Simple Efficiency Interrelations 680References .682Appendix B: Heat Addition to a Supersonic Gas Flow 682

I. Constant Pressure Heat Addition in a Duct 682II. Constant Mach Number Heat Addition in a Duct 683

III. Heat Addition in a Constant Area Duct 683IV. Heat Addition in a General Diverging Area Duct 684V. Heat Addition Following a Shockwave 684

VI. Efficiencies in Heat Addition 688References 689Appendix C: Hydrogen Combustion Scheme 689

I. Thermodynamic Properties 690II. Equilibrium and Nonequilibrium Combustion 690

Appendix D: Three-Dimensional Nozzles—Design andIntegration 693

I. Internal Flowpath 693II. Integration with the Vehicle External Flow 694

Chapter 11 Strutjet Rocket-Based Combined-Cycle Engine 697I. Introduction 697

II. Strutjet Engine 698A. Flow-Path Description 699B. Engine Architecture 701C. Strutjet Operating Modes 707D. Optimal Propulsion System Selection . . 712

III. Strutjet Engine/Vehicle Integration 717A. Strutjet Reference Mission 717B. Engine-Vehicle Considerations 720C. Vehicle Pitching Moment 720D. Engine Performance 721E. Reduced Operating Cost Through Robustness 722F. Vehicle Comparisons 729

IV. Available Hydrocarbon and Hydrogen Test Data andPlanned Future Test Activities 733

A. Storable Hydrocarbon System Tests . 734B. Gaseous Hydrogen System Tests . 744C. Planned Flight Tests 750

V Maturity of Required Strutjet Technologies 753VI. Summary and Conclusions 753

A. Hydrogen and Hydrocarbon Strutjet Engines 755B. Strutjet Technology Maturity 755C. Overall Recommendation 755References 755

CONTENTS xv

Chapter 12 Liquid Hydrocarbon Fuels forHypersonic Propulsion 757

Nomenclature 757I. Introduction 758

II. Fuel Heat-Sink Requirements and the Role ofEndothermic Fuels 762

A. Characteristics of Endothermic Fuels 763B. Fundamental Considerations of Heat Removal 768

III. Fuel System Challenges 769A. Thermal Stability 771B. Structural and Heat Transfer Considerations 781C. Fuel-System Integration and Control 783

IV. Combustion Challenges 784A. Chemical Kinetic Foundations 788B. Present State of Chemical Kinetics 797C. Combustor Development Considerations 800D. Prospects for Modeling Large Kinetic Systems 801

V. Summary 802Acknowledgments 802Bibliography 802Addendum—Recent Work 813Appendix: Basic Elements of Chemical Kinetic Mechanisms . . . 814Thermochemical and Kinetic Databases 814Construction and Validation of Comprehensive

Combustion Models 815Formal Routes to Sensitivity Analyses andMechanism Reduction 817Skeletal Models 820

Chapter 13 Detonation-Wave Ramjets 823Introduction 823

Experimental Evidence of Standing Detonation Waves . \. . . . 828Operating Envelope of Standing Detonation Waves . . . . . . . . . 834Fuel/Air Premixing Process 841Performance Analysis 847Scramjet/Airframe-Integrated Waverider 879Concluding Remarks 883Acknowledgments 885References :. . 885

Chapter 14 Problem of Hypersonic Flow Decelerationby Magnetic Field 891

Introduction 891Peculiarities of MHD Control . 891Review of Proposals to Use MHD Control . . . 892

xvi CONTENTS

Contents of the Present Article . . . . ' . 897Relative Value of MHD Effects in Hypersonic Airflows 898Electroconductivity of Air and Dimensionless MHD Parameters

Behind a Normal Shock Wave in a Hypersonic Flow 898Evaluation of Capabilities of Conductivity Increase in Pure Air . 899Equations of Magnetic Gas Dynamics at Small Magnetic

Reynolds Numbers. Main Parameters. Methods ofNumerical Analysis 901

Equations of Magnetic Gasdynamics and MainDimensionless Parameters 901

Parameters Describing Irreversible Losses in MHD Flows . . . . 904MHD Deceleration of a Hypersonic Flow in

One-Dimensional Approach 906Numerical Method for Solution of MHD Equation System . . . . 908Boundary-Layer Separation Parameter in

Magnetogasdynamics 909Parameter of Boundary-Layer Separation in the Case of

Nonconducting Wall 909Parameter of Boundary-Layer Separation in the Case of

Conducting Wall 914Deceleration of a Supersonic Flow in a Circular

Nonconducting Tube by an Axisymmetric Magnetic Field . . 915Flow Deceleration in a Circular Tube by Magnetic Field

of a Single-Current Loop 915Flow Deceleration in a Circular Tube by Magnetic Field

of a Solenoid 922Deceleration of Two-Dimensional Supersonic Flow in

Channels by Magnetic Field Perpendicular to a FlowPlane In Generator Regime 928

Formulation of a Problem - -: - 928Quasi-One-Dimensional Approximation for

Electrical Variables 930Numerical Analysis of Laminar and Turbulent Flows . . . . . . . . 932Conclusions < , . . . . 934References 936

Chapter 15 Rudiments and Methodology for Design and Analysis ofHypersonic Airbreathing Vehicles 939

Introduction . 939Rudiments of Design 941Coordinate System 941Force Accounting System 942Nominal SSTO Vehicle/Trajectory 945Loads 946Stability and Control '. 948Representative Forces and Moments 950

CONTENTS xvii

Impact of Propulsion Lift on Aerodynamics 952Engine/Airframe Integration Methodology 956Engineering Methods 957Higher-Order Numerical Methods 966Vehicle Design Methodology 968Aerodynamics/Aerothermodynamics .969Structures/TPS Sizing 969Closure 971Vehicle Performance 971Synthesis/Sizing 972Design Automation/Optimization 972Summary 975Acknowledgments 975References 975

Chapter 16 Transatmospheric Launcher Sizing 979Nomenclature 979

I. Introduction 982A. Theme 982B. Objectives 983

II. Vehicle Sizing Approach 983A. Approach 984B. Sizing Methodology 985C. Fundamental Sizing Relationships 987D. Effect of r on Configuration Concepts 989E. Parametric Sizing Interactions 989F. Summary of Parameter Groups 990G. External Aerodynamics 992H. Technology Maturity Determination 994

III. Propulsion Systems 996A. Performance Characteristics of Air Breathing Engines . . . . 997B. Major Sequence of Propulsion Cycles 1000C. Cycle Comparison '•-.... 1007

IV. Sizing Code 1011A. Hypersonic Convergence Sizing Code 1011B. Final Hypersonic Convergence Relationships 1012C. Vandenkerckhove Sizing Code 1014

V. VDK Sizing Approach 1014A. Weight Budget . 1016B. Volume Budget 1018C. Input Values Assumptions 1019D. Volume and Weight Assumptions 1020E. Aerodynamics ': 1021F. Propulsion 1021G. Trajectory 1022

VI. SSTO Launcher Sizing 1022

xviii CONTENTS

A. Determination of Vehicle Length 1023B. Design 1026C. Mission 1039D. Geometry 1043E. Strong Parameter Cross-Couplings 1048

VII. TSTO Launcher Sizing 1051A. Assumptions 1052B. Volume and Weights 1053C. Propulsion 1053D. Aerodynamics 1053E. Trajectory 1054F. First Stage 1054G. Second Stage 1056H. TSTO Sizing Results 1057I. Influence of First Stage Propulsion Concept 1058J. Discussion of Results 1058

VIII. Comparison Between SSTO and TSTO 1059IX. Air Liquefaction and LOX Collection 1063

A. Propulsion System Configuration 1063B. Sizing Model Modifications and Assumptions 1065C. Application to SSTO 1067D. Application to TSTO 1072E. Summary 1072

X. Conclusions 1075References 1076Appendix A: Hypersonic Configuration Geometric

Characteristics 1084Appendix B: Impact of Lower Speed Thrust Minus Drag . . . . 1088Propulsion Airframe Strong Interactions 1089References *-.-. 1091Appendix B: Impact of Lower Speed Thrust Minus Drag . . . . 1095Propulsion Airframe Strong Interactions 1097References 1103

Chapter 17 Scramjet Flowpath Integration 1105I. Background 1105

A. Scramjet-Powered Vehicles 1105B. Flowpath Optimization 1112

II. Energy Analysis . 1117A. Hypersonic Energy Partitioning 1119B. Summary and Statement of the Design Problem 1122

III. Inlet : . 1124A. Some Useful Direct Relations 1125B. Flowfield in the Inlet Flowpath Introduces

Distortion Parameters 1127C. Determination of #W P 1129

CONTENTS xix

D. Inlet Testing and Determination of /Cwp 1130E. Implications of Thermodynamic Analysis

to Design of Inlets 1132IV. Forebody 1134

A. Forebody Design 1134B. Inlet Forebody Integration 1137

V. Force Accounting 1140A. Force Accounting Viewpoint 1138B. Lift Drag 1150C. Flow Turning and Overall Design of Inlet 1152D. Force Accounting Approaches 1158

VI. Combustor 1158A. Isolator 1159B. Dual-Mode Combustor Isolator 1161C. Detonation Wave Engine 1168D. Application to a Dual-Mode Combustor 1169E. Scramjet 1177F. Friction Cycle 1181G. Step Combustor , 1190H. Summary 1196

VII. Nozzle Component Losses 1196A. Standard Loss Categories 1197B. Expansion Process Physics 1198

VIII. Integration Results 1201A. Partitioning of Internal Flowpath 1201B. Engine Module Flowpath Integration 1202C. Scramjet Integration and Example 1204D. Vehicle Mass Properties 1204E. Mass Fraction Required 1205F. Closure -. . : 1208

IX. Summary and Recommendations 1213Bibliography 1216Appendix A: Dynamics of a Flight Vehicle 1218A. Cruise Flight 1218B. Accelerated Flight 1219C. Application to a Constant Isp Engine 1219D. Application to a Constant V-Isp Engine 1220Appendix B: Brayton Cycle Scramjet 1221Appendix C: Aerothermodynamics of Scramjet Engine 1222A. Pressure Coefficient 1222B. Engine Cycle Thermodynamic Functions 1224C. Boundary-Layer Influence 1226D. Experimental Determination of Inlet KwP 1232E. Ratio of Specific Heats for Air 1236F. Further Analysis of Thermal Ratio 1238Appendix D: Hypersonic Slender Body Theory Applied to

Forebodies and Leading Edges 1240

xx CONTENTS

A. Forebodies 1240B. Leading Edges 1243C. Case of Unequal Angles 1244D. Overspeed Situation in an Inlet 1245Appendix E: Scaling Drag and Heat Transfer 1249A. Skin-Friction Coefficient 1249B. Heat Transfer 1252Appendix F: Force Accounting Procedures 1254A. Freestream Force Accounting 1257B. Cowl-to-Tail Accounting 1257C. Lift Effects 1257Appendix G: Geometry and Mass of Integrated Vehicle . . . . 1258A. Geometry 1258B. Weight Analysis 1262Appendix H: Two-Wave Combustion Model for Optimal

Supersonic Combustion Performance 1269A. Heat Addition in a Dual-Mode Combustor 1269B. Scramjet Two-Wave Combustor 1275Appendix I: Base Pressure Estimate 1280A. Required Pressure at Reattachment 1280B. Closure 1289

Nomenclature for Flow Path Component Specification 1290