Aerospace Propulsion Systems

Thomas A. Ward is a Senior Lecturer of Mechanical Engineering at the Unitversiti Teknologi Mara (UiTM), Malaysia, where he teaches aerospace propulsion systems, heat transfer, and fluid mechanics. He acts as Aero Propulsion Coordinator for the UiTM Flight Technology and Test Center and been a Senior Advisor to the Google Lunar X-Prize Malaysian team. Ward also serves as Technical Editor for UiTM International Engineering journal and referee for the Institute of Engineers, Malaysia (IEM) journal. Prior to his move to Malaysia, Ward worked as an Aerospace Engineer for the US Air Force for over 15 years, conducting integrated engineering analysis of aircraft systems including propulsion systems, aerodynamics, flight controls, structures, avionic systems, and flight dynamics. He represented the USAF on several national committees and at numerous forums and international events. International outreach included working in the United Kingdom for five years as a USAF Integrated Engineer with the Royal Air Force. Ward has conducted research on endothermic jet fuels for potential future use in hypersonic aircraft and has authored a number of propriety papers on aircraft and missile systems for the USAF. He holds a BSc in Aerospace Engineering from the University of Cincinnati, an MSc in Aerospace Engineering from the University of Dayton, an MSc in Aerospace Systems Engineering from Loughborogh University, and a PhD in Mechanical Engineering from the University of Dayton.

Preface ix Acknowledgments xi Outline of Aerospace Propulsion History xiii Nomenclature xvii 1 Fundamentals 1 1.1 Fundamental Equations 2 1.1.1 Review of Terms 4 1.1.2 Equation of State for a Perfect Gas 12 1.1.3 Law of the Conservation of Mass 13 1.1.4 Law of the Conservation of Linear Momentum 15 1.1.5 Law of the Conservation of Energy 17 1.2 Isentropic Equations 21 1.2.1 Isentropic Relationship between Temperature and Pressure 21 1.2.2 Isentropic Relationships with Specific Volume 23 1.3 Polytropic Processes 25 1.4 Total (or Stagnation) Properties 25 1.5 Isentropic Principles in Engine Components 31 1.5.1 Ducts 31 1.5.2 Turbomachinery 34 1.5.3 Combustion Chambers (Combustors) 34 1.5.4 Nozzles 34 1.6 Shock Waves 41 1.6.1 Normal Shocks 42 1.6.2 Oblique Shocks 46 1.6.3 Conical Shocks 50 1.7 Summary 51 References 51 Problems 51 2 Rockets 57 2.1 Background Description 57 2.2 Performance of an Ideal Rocket 60 2.2.1 Rocket Thrust Equation 63 2.2.2 Total and Specific Impulse 66 2.2.3 Effective Exhaust Velocity 68 2.2.4 Rocket Efficiencies 69 2.2.5 Characteristic Velocity 70 2.2.6 Thrust Coefficient 74 2.3 Solid Rocket Motors 81 2.3.1 Colloidal (Homogenous) Propellants 83 2.3.2 Composite (Heterogeneous) Propellants 90 2.3.3 Composite Modified Double-Based Propellants 93 2.3.4 Solid Propellant Grain Geometry 93 2.3.5 Solid Rocket Motor Casing 102 2.3.6 Combustion of Solid Propellants 103 2.3.7 Solid Rocket Ignition Systems 107 2.4 Liquid Rockets 111 2.4.1 Liquid Rocket Propellants 111 2.4.2 Liquid Rocket Feed Systems 124 2.4.3 Liquid Rocket Injection Systems 125 2.4.4 Combustion of Liquid Propellants 127 2.4.5 Liquid Rocket Ignition Systems 129 2.5 Hybrid Rockets 130 2.6 Motor Casing 131 2.7 Thrust Chamber 133 2.8 Exhaust Nozzles 137 2.9 Multi-staging 141 2.10 Non-chemical Rockets 149 2.11 Rocket Design Methodology 150 2.12 Summary 160 References 161 Problems 162 3 Piston Aerodynamic Engines 171 3.1 Background Description 171 3.2 Engine Types 176 3.2.1 Rotary Engines 176 3.2.2 Reciprocating Engines 178 3.2.3 Supercharged Reciprocating Engines 191 3.2.4 Gas Turbine Propeller Engines 194 3.3 Thrust 198 3.4 Combustion 202 3.4.1 Aviation Fuel 202 3.4.2 Specific Fuel Consumption 205 3.5 Propeller Design 213 3.5.1 General Description 213 3.5.2 Power Efficiencies 217 3.5.3 Variable Pitch Blades 225 3.5.4 Propeller Shapes 227 3.5.5 Contra-Rotating Propellers 228 3.5.6 Helicopter Rotor Blades 229 3.6 Propeller Performance 230 3.7 Summary 239 References 239 Problems 240 4 Gas Turbine Engines 247 4.1 Background Description 247 4.2 Ideal Gas Turbine Cycle 253 4.3 Types of Gas Turbine Engines 255 4.3.1 Jet Propulsion Engines 255 4.3.2 Shaft Power Engines 260 4.4 Engine Cycle Performance 264 4.4.1 Jet Propulsion Thrust 264 4.4.2 Shaft Power Thrust 267 4.4.3 Propulsive Efficiency 268 4.4.4 Thermal Efficiency 270 4.4.5 Overall Efficiency 270 4.4.6 Specific Fuel Consumption 271 4.5 Component Performance 272 4.5.1 Intakes 272 4.5.2 Compressors 275 4.5.3 Turbines 276 4.5.4 Combustion Chambers (Combustors) 277 4.5.5 Exhaust Nozzles 279 4.6 Engine Performance Analysis 281 4.7 Design Point Optimization 321 4.8 Component Design 326 4.8.1 Intake Design 326 4.8.2 Compressor System Design 338 4.8.3 Combustion Chambers 357 4.8.4 Turbines 366 4.8.5 Exhaust Systems 372 4.9 Engine Control Systems 378 4.10 Summary 379 References 379 Problems 380 5 Ramjet and Scramjet Engines 395 5.1 Background Description 395 5.2 Ramjet Engines 400 5.2.1 Conventional Ramjet Engines 400 5.2.2 Turboramjet Engines 403 5.2.3 Analysis of Ramjet Engines 404 5.2.4 Ramjet Component Design 426 5.3 Scramjet Engines 431 5.3.1 Description 431 5.3.2 Scramjet Component Design 434 5.4 Summary 437 References 438 Problems 438 Appendix A: Gas Tables