Hypersonic Air-Breathing Propulsion


Revolutionary methods of high speed air-breathing propulsion (HAP) are needed to extend the flight regime of aircraft, missiles, and improve Earth-to-orbit spacecraft. This course explores the technologies required for the successful development of dual-mode scramjet engines for applications to hypersonic missiles and hypersonic aircraft. Using a solid theoretical background, we review the high-performance systems required for ram/scramjet operation in all hypersonic regimes, emphasizing vehicle integration and compatibility with other propulsion cycles proposed for different vehicle applications. We will present the necessary background in supersonic combustion kinetics, high-temperature materials, aero-structures and thermal management, as required to advance HAP technologies.

What You Will Learn
  • Explore the technologies required for the successful development of propulsion systems for hypersonic missiles and hypersonic cruise aircraft.
  • Review design of key components common to most hypersonic air-breathing propulsion (HAP) systems, such as inlets, isolators, combustors, fuel injectors, flame-holders, and nozzles.
  • Evaluate the performance requirements for dual-mode scramjet operation in all flight regimes, emphasizing vehicle integration and compatibility with the different hypersonic applications.
  • Study the relationships and interface of analysis, design, CFD modeling and simulation, ground testing, and demonstration flights.
  • Gain technical background on high-temperature materials, aero-structures, fuel injection and supersonic combustion kinetics.
  • Using examples of past designs and analyses, you will obtain guidelines for using appropriate computational tools in the various stages of HAP development.
Key Course Topics
  • Introduction to Hypersonic Air-breathing Propulsion
  • Hypersonic Flow Theoretical Background
  • Aerothermodynamics of Aircraft Integrated Scramjet
  • Thermodynamic Cycle Analysis and Propulsion Performance
  • Dual-Mode Combustion
  • Advanced Materials, Aerostructures and Thermal Management
  • Combined Cycle Propulsion: Technical Issues
  • CFD, Ground Testing, and Flight Demonstration
Who Should Attend

This course is designed for engineers, students, test personnel and managers who want to improve their understanding of state-of-the-art high-speed air-breathing propulsion.

Course Information

Type of Course: Instructor-Led Short Course
Course Level: Intermediate/Advanced
Course Length: 1-3 days
AIAA CEU's available: Yes


Introduction to Hypersonic Air Breathing Propulsion 
1.1 Definition of Hypersonic Flight and Hypersonic Flow 
1.2 Types of Hypersonic Vehicles 
1.3 Ram/Scramjet Operating Principle 
1.4 Main Scramjet Engine Components:

  1. Inlet and Isolator
  2. Combustor
  3. Nozzle

1.5 Engine-Vehicle Integration 
1.6 Hypersonic Propulsion Challenges 
1.7 Propulsion Performance Comparison 
1.8 HAP Corridor and Dynamic Pressure 
1.9 Technology Issues 
1.10 Critical Design Issues 
1.11 X-43A and X-51A Flight Demonstrators 
1.12 Current and Future HAP Programs 
1.13 HAP Programs around the World

Review of Fundamental Principles 
2.1 Earth’s Atmosphere 
2.2 Calorically perfect gas and Thermally perfect gas 
2.3 Hypersonic Inviscid Flow Fields 
2.4 Euler Equations 
2.5 Steady Aerothermodynamic Equations 
2.6 Total Enthalphy and Total Temperature 
2.7 Total Pressure 
2.8 Ideal Exit Flow Velocity and Mass Flow 
2.9 Impulse and Stream Thrust Function 
2.10 Constant Area Heating and Thermal Chocking 
2.11 Shock Waves: Oblique Shocks, Normal Shocks, and Expansion Flow Relations

Aerothermodynamics of Aircraft Integrated Scramjet 
3.1 Propulsion Airframe Integration (PAI) 
3.2 Aerothermodynamics 
3.3 Hypersonic Vehicles 
3.4 Flight Environment 
3.5 Thermal Environment for Hypersonic Vehicles 
3.6 Vehicle Forebody 
3.7 Inlet Capture, Shock Ingestion, and Spillage 
3.8 Vehicle Angle of Attack 
3.9 Boundary Layers 
3.10 Engine Starting 
3.11 Combustor/Inlet Interaction 
3.12 Combustor Flowfield (Fuel Injection and Mixing) 
3.13 Combustor/Nozzle Interaction 
3.14 Nozzle External Burning 
3.15 Propulsion Airframe Integration (PAI) Issues 
3.16 Tip-to-Tail HAP Vehicle Analysis Tools

HAP Inlets, Isolators, and Nozzles 
4.1 Inlet Function and Operating Modes  
4.2 Inlet Types  
4.3 Inlet Aerodynamics  
4.4 Inlet Design Issues

  1. Starting and Contraction Limits
  2. High Temperature Effects
  3. Blunt Leading Edge
  4. Boundary Layer Separation
  5. Isolators
  6. Combustor Entrance Profiles

4.5 Inlet Designs

  1. 2-D Inlets
  2. 3-D Inlets

4.6 Performance and Operability  
4.7 Isolator

  1. Shock Train
  2. Isolator Length

4.8 Nozzle Configurations 
4.9 Nozzle Aerodynamics

  1. On and Off-Design
  2. Flow Separation

4.10 Design Tools  
4.11 Performance Parameters

  1. Mass Flow
  2. Thrust Coefficient
  3. Losses

4.12 Remarks about SERN for High M0  
4.13 Translating-Throat SERN  
4.14 Nozzle Concept for RBCC Vehicles  
4.15 A Scramjet Nozzle Testing

HAP Combustors and Fuels 
5.1 Combustion Process Desired Properties  
5.2 Combustor Entrance Conditions  
5.3 Fuels for Hypersonic Propulsion

  1. Fuel Energy for Combustion
  2. Fuel Cooling Capacity
  3. Endothermic Fuels

5.4 The Combustion Process

  1. Reaction Rates
  2. Stoichiometric Fuel/Air Ratio and Equivalence Ratio

5.5 Scramjet Combustion Design Issues

  1. Thermal Throat
  2. Fuel Distribution and Mixing
  3. Ignition and Reaction Times

5.6 Fuel Injection and Fuel/Air Mixing

  1. Fuel Injectors
  2. Flameholding

Dual-Mode Combustion 
6.1 The Ramjet and its Ideal Performance 
6.2 Dual-Mode Combustion Propulsion Concept 
6.3 1-D Ideal Flow in Burner 
6.4 Billig’s Dual-Mode Scramjet Study 
6.5 Isolator Shock-Trains 
6.6 Isolator Length for Dual-Mode Scramjet 
6.7 Dual-Mode Transition 
6.8 Dual-Mode Scramjet Propulsion Challenges 
6.9 HIFiRE Dual-Mode Combustor System 
6.10 Dual-Mode, Free-Jet Combustor Concept

Materials, Structures and Thermal Management 
7.1 Aerodynamic Heating  
7.2 Convective Heat Transfer  
7.3 Stagnation Point Heating and Vehicle Nose Radius  
7.4 Hypersonic Vehicle Heating  
7.5 Thermal Management Options  
7.6 Passive and Active Cooling Methods  
7.7 Hypersonic Integrated Structures  
7.8 Cooling Requirements  
7.9 Hypersonic Hot and Warm Structures  
7.10 A Look at the X-43A Thermal Protection System  
7.11 Hypersonic Materials and Structures Technical Challenges

Combined Cycle Propulsion: Technical Issues

  1. Characteristic Earth Flight Trajectories
  2. Airbreathing Hypersonic Vehicles
  3. Challenge of Hypersonic Air Breathing Propulsion (HAP)
  4. Combined Cycle Definition
  5. Requirement for a HAP Combined Cycle Propulsion
  6. Combined Cycle Proposed Concepts
    1. Turbine-Based Combined Cycle (TBCC)
    2. Rocket-Based Combined Cycle (RBCC)
  7. Combined Cycle Development Issues
  8. Technical Challenges
  9. Spaceplanes
    1. SSTO
    2. TSTO
  10. TBCC Propulsion for TSTO Vehicles
  11. Air-breathing Rocket (SABRE)
  12. Other Combined Cycle Propulsion Concepts

CFD, Ground Testing, and Flight Demonstration

  • A brief overview of key physics and analysis, ground and flight test requirements associated with performance and operability of hypersonic air-breathing propulsion (HAP) systems (airframe-integrated scramjet and dual-mode scramjet engine). It highlights important aspects of the pillars of HAP vehicle development.
Dr. Dora E. Musielak has over 30 years of experience directing R&D projects in industry and academia, developing key expertise in high-speed air breathing propulsion and liquid chemical rockets. As a chief scientist she led a scramjet propulsion development program sponsored by the U.S. government. Musielak has authored numerous reports and papers related to high speed propulsion (scramjets, rockets, and PDEs), with focus on numerical simulation of fuel injection, high speed reacting and nonreacting turbulent flows. 

An AIAA Associate Fellow, Dr. Musielak has served in several national technical committees, including the NRC Committee on Breakthrough Technology for Commercial Supersonic Aircraft, the AIAA Pressure Gain Combustion Program Committee (PGC PC), and the AIAA High Speed Air Breathing Propulsion TC, a committee she chaired from 2014 to 2016.


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