Fundamentals of Aircraft and Rocket Propulsion

ThiS is a FM Blank Page

Ahmed F. El-Sayed

Fundamentals of Aircraftand Rocket Propulsion

Ahmed F. El-SayedDepartment of Mechanical EngineeringZagazig UniversityZagazig, Egypt

ISBN 978-1-4471-6794-5 ISBN 978-1-4471-6796-9 (eBook)DOI 10.1007/978-1-4471-6796-9

Library of Congress Control Number: 2016940096

© Springer-Verlag London 2016The author(s) has/have asserted their right(s) to be identified as the author(s) of this work in accordancewith the Copyright, Design and Patents Act 1988.This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part ofthe material is concerned, specifically the rights of translation, reprinting, reuse of illustrations,recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmissionor information storage and retrieval, electronic adaptation, computer software, or by similar ordissimilar methodology now known or hereafter developed.The use of general descriptive names, registered names, trademarks, service marks, etc. in thispublication does not imply, even in the absence of a specific statement, that such names are exemptfrom the relevant protective laws and regulations and therefore free for general use.The publisher, the authors and the editors are safe to assume that the advice and information in thisbook are believed to be true and accurate at the date of publication. Neither the publisher nor theauthors or the editors give a warranty, express or implied, with respect to the material containedherein or for any errors or omissions that may have been made.

Printed on acid-free paper

This Springer imprint is published by Springer NatureThe registered company is Springer-Verlag London Ltd.

To my parents whose endless love, support,and encouragement were a constant sourcefor my inspiration

ThiS is a FM Blank Page

Preface

Pedagogically, the fundamental principles are the foundation for lifelong learning.

Thus, this book through a simple treatment can provide students of aerospace/

aeronautical and mechanical engineering with a deep understanding of both aircraft

and spacecraft propulsions. The development of aircrafts in only one century is far

beyond expectations.

December 1903 was the dawn of human-engineered flight when the Wright

Brothers flew their first flights that lasted for a few seconds in Ohio, USA. This

first aircraft was powered by a single piston engine and had no passengers, neither

did it have a fuselage nor landing gears. It is extremely amazing that in 2011 over

2.8 billion passengers were carried by the world’s commercial airlines via more

than 222,500 aircrafts powered by more than 260,000 different types of aero

engines. Some of these aircrafts can carry as many as 800 passengers for more

than 15 h of flying time, while others can fly at supersonic speeds. In 2015, the

number of passengers exceeded 3.3 billion. Now, piston engines are no longer the

single actor in propulsion theater, though they are still dominant! Turbojet engines

were the first jet engines invented in the late 1930s and took a reasonable share in

military and civil-powered flights for nearly two decades. In the late 1950s and

early 1960s, turbofan engines (or bypass turbojet engines) were invented. These are

the present prevailing engines which power faster, quieter, cleaner, and heavier

aircrafts. In the 1950s also two other engine types, namely, turboprop and turbo-

shaft, were invented to power commercial airliners and military transport aircrafts

and rotorcrafts.

Due to the rapid advance in air transportation as well as military and intelligence

missions, aircraft and rocket propulsion has become an essential part of engineering

education. Propulsion is the combined aero-thermal science for aircrafts and

rockets. Propulsion has both macro- and microscales. Macroscale handles the

performance and operation of aircrafts and rockets during different missions,

while microscale is concerned with component design including both rotary mod-

ules (i.e., compressor, fan, pump, and turbine) and stationary modules (i.e., intake,

combustor, afterburner, and nozzle).

vii

The primary aim of this text is to give students a thorough grounding in both the

theory and practice of propulsion. It discusses the design, operation, installation and

several inspections, repair, and maintenance aspects of aircraft and rocket engines.

This book serves as a text for undergraduate and first year graduate students in

mechanical, aeronautical, aerospace, avionics, and aviation engineering depart-

ments. Moreover, it can be used by practicing engineers in aviation and gas turbine

industries. Background in fluid mechanics and thermodynamics at fundamental

levels is assumed. The book also provides educators with comprehensive solved

examples, practical engine case studies, intelligent unsolved problems, and design

projects. The material of this book is the outcome of industrial, research, and

educational experience for more than 40 years in numerous civil, military institu-

tions, and companies of 9 countries including the USA, Russia, Austria, UK,

Belgium, China, and Japan as well as Egypt.

The book is composed of 11 chapters and 4 appendices. The first ten chapters

handle air-breathing engines, while non-air-breathing (or rocket) engines are ana-

lyzed in Chap. 11.

Chapter 1 is rather a unique one! It provides a rigorous classification of all types

of aircrafts and its sources of power. The first part classifies aircrafts as aerostats/

aerodynes, fixed wing/rotary wing (or rotorcrafts), and hybrid fixed/rotary wings as

well as all other lift aircrafts (flapping wing or ornithopter, lifting body, and fan

wing). The second part handles power plant types. Power plants belong to two main

groups, namely, external and internal combustion engines. External combustion

engines are steam, Stirling, and nuclear engines. Internal combustion engines are

further classified as shaft and reaction engines. Shaft engine group is either of the

intermittent combustion types (Wankel and piston) or continuous combustion types

(turboprop, turboshaft, and propfan). Reaction engines are either of the athodyd or

turbine engines. Athodyd engines include ramjet, scramjet, and pulsejet (valved,

valveless, and pulse detonation types). Finally, turbine-based engines include

turbojet, turbofan, and turbo-ramjet engines.

Chapters 2 and 3 emphasize that a few fundamental physical principles, rightly

applied, can provide a deep understanding of operation and performance of aircrafts

and space vehicles.

Chapter 2 provides a review of basic laws of compressible flow with heat and

friction. Conservation of mass, momentum, moment of momentum, and energy

equations applied to open control volume are reviewed. A review for aspects of

normal and oblique shock waves and Fanno and Rayleigh flows follows. Flow in

diffusers in aircrafts as well as flow in nozzles in both aircrafts and rockets are

discussed. Standard atmosphere is highlighted to emphasize variations of air prop-

erties at different altitudes.

Chapter 3 relies upon governing formulae reviewed in Chap. 2 in driving the

different performance parameters of jet propulsion, namely, thrust force, operation

efficiencies (propulsive, thermal, and overall), specific impulse, and fuel consump-

tion. Other parameters that couple aircraft and engine performance like aircraft

viii Preface

range and endurance are presented. Analysis of aircraft mission, route planning, and

non-return point are next highlighted.

Chapter 4 provides the necessary analyses of piston engines and propellers.

Though piston engine was the first in-flight air-breathing engine employed by the

Wright brothers in 1903, it maintains its strong existence until now. It represents

more than 70 % of present-day air-breathing engines. They are extensively used in

small fixed wing, sport aircrafts, UAVs, and lighter than air flying vehicles, as well

as many rotorcrafts. Unfortunately, it is overlooked in most available propulsion

books. A concise analysis of power cycles for two- and four-stroke engines,

compression or spark ignition (CI and SI), and Wankel engines as well as turbo-

and superchargers is reviewed for power and thermal efficiency optimization.

Piston engines cannot generate the necessary propulsive force for a flying vehicle

on its own. Thus, it should be coupled to propellers. Classifications of propellers

based on various aspects are defined. Propeller’s power and thrust force coefficientsare defined using simple aerodynamic theories (momentum, modified momentum,

and blade-element).

Chapter 5 is devoted to athodyd (nonrotating modules) engines, namely,

pulsejet, ramjet, and scramjet engines. All cannot produce thrust force at zero flight

speed, so other propulsive methods are used for takeoff operation. Each engine is

composed of intake, combustion chamber, and nozzle. An analysis of ideal and real

cycles as well as performance parameters of all engines is identified. Pulsejet

engine is an internal combustion engine that produces thrust intermittently and is

either of the valved or valveless type. Pulse detonation engine (PDE) is evolved in

the last decade. PDE promises higher fuel efficiency (even compared with turbofan

jet engines). Ramjet engine represents the first invented continuous combustion

engine. It is used in both aircrafts and rockets. The third engine analyzed in this

chapter is scramjet (supersonic combustion ramjet). Combustion takes place in

supersonic airflow. Thus it can fly at extremely high speeds (NASA X-43A reached

Mach 9.6). Finally, dual-mode (Ram-Scram) combustion engine is analyzed.

Chapters 6 and 7 treat air-breathing engines incorporating rotating modules.

Chapter 6 handles turbine-based engines (turbojet, turbofan, and turbo-ramjet),

while Chap. 7 treats shaft-based engines (turboprop, turboshaft, and propfan).

One of the objectives of both chapters is to exercise students to practice realistic

engines, build confidence, and a sense of professionalism. Both chapters start with a

historical prospective and a classification of each engine. Next, thermodynamic and

performance analyses for ideal and real cycles are introduced and further explained

via solved examples. Chapter 6 starts by the first flown jet engine, namely, turbojet

engine, which was coinvented in the 1930s by British and German activities.

Analyses of single and double spools in the presence and absence of afterburner

are described. Though rarely used in airliners or military planes in present days, it is

still used in micro turbojets and turbojets powering rockets during sustained flight.

Turbofan engines are continuing its superiority for most present commercial

airliners and military planes as well as some rockets for sustained flight. A unique

classification of the numerous types of this engine based on fan location

Preface ix

(forward/aft), bypass ratio (low/high), number of spools (single/double/triple),

number of nozzles (single/double), fan/turbine coupling (geared/ungeared), and

finally afterburner (present/absent) is given. After detailed analyses for some (not

all) types of turbofan, the third engine, namely, turbo-ramjet, is presented. It is

found in two configurations: wraparound or above/under types. An analysis of its

single mode or combined mode is precisely defined.

Chapter 7 is confined to shaft-based engines in which performance is controlled

by shaft power rather than thrust force. Also, its economy is governed by brake-

specific fuel consumption rather than thrust-specific fuel consumption. Turboprop

engines power manned and unmanned aircrafts. It may be of the puller (tractor) or

pusher types. It may be also either a single or double spool. This section is ended by

an analogy between turboprop and turbofan engines. Next, turboshaft engines

which mainly power helicopters are classified and analyzed. Exhaust speeds are

no longer important in this type of engines as all available energy is converted into

shaft power. Finally, propfan or unducted fan (UDF) engines, normally described as

ultrahigh bypass (UHP) ratio engine, are classified based on fan location (forward/

aft) and numbers of fan stages (single/double). A thermodynamic analysis of this

engine is presented for the first time in this book. It combines features from both

turbofan and turboprop engines.

Chapter 8 presents aero-/thermodynamic analyses of stationary modules of jet

engines, namely, intakes, combustion chamber, afterburner, and nozzle. At first,

different methods for power plant installation (wing/fuselage/tail, or combinations)

are discussed as it has a direct influence on air flow rates into intakes and ingestion

of foreign objects into the engines. Also, intakes for fixed and rotary wing aircrafts

as well as rockets are described. Moreover, subsonic and supersonic intakes are

reviewed for optimum jet engine performance. Intake geometry and its perfor-

mance are also presented. A review of combustion chambers including types,

chemistry of combustion, aerodynamics, and thermodynamics of flow in its differ-

ent elements is presented. Afterburners in turbojets/turbofans in supersonic aircrafts

are analyzed. Different types of aviation fuels and biofuels as a future jet fuel for

green aviation are examined. The exhaust system is treated here in a general scope.

Convergent and convergent divergent (de Laval) nozzles are analyzed. Moreover,

thrust reverse and thrust vectoring are reviewed. Noise control for nozzles is given.

Turbomachinery (i.e., fans, compressors, and turbines) are treated in Chaps. 9

and 10. The objective of both chapters is to provide a simplified understanding of its

aerodynamics, thermal, and stresses in both compressors and turbines. In Chap. 9,

different types of compressors are first identified, but only centrifugal and axial flow

types are analyzed. The three main components of centrifugal compressor, namely,

impeller, stator, and volute/scroll, are first analyzed taking into consideration their

different types. Positive/negative prewhirl is also presented. Concerning axial

compressor, the aerodynamics of single and multistages is reviewed. A perfor-

mance map for both compressors is employed in identifying design and off-design

operation. Lastly, different mechanisms for avoiding surge and rotating stall are

discussed.

x Preface

Chapter 10 treats radial and axial flow turbines. Radial turbine is to a great extent

similar to centrifugal compressor. The aerodynamics and thermodynamics of its

components (i.e., inlet, nozzle, rotor, and outlet duct) are presented. Next, single

and multistage axial flow turbines are treated with either impulse or reaction

blading. Mechanical design and cooling techniques are reviewed. Finally, turbine

map and off-design performance of both turbines are discussed. Matching between

compressors and turbines in both gas generators and jet engines ends this chapter.

Rocket propulsion is discussed in Chap. 11. It starts with a brief history of

rocketry followed by classifications of rockets based on type, launching mode,

range, engine, warhead, and guidance systems. Rocket performance parameters

(i.e., thrust force, effective exhaust velocity, specific impulse, thrust coefficient, and

combustion chamber pressure drop) are derived in closed forms similar to those in

Chap. 3 for air-breathing engines. A comprehensive section for multistaging is

presented. Finally, an analysis of exhaust system (i.e., nozzle geometry, exhaust

velocity, and structural coefficient) is given. Both chemical and nonchemical rocket

engines are reviewed. Chemical rockets are further divided into liquid, solid, and

hybrid rockets. Solid propellant types, combustion chamber, and nozzles are

defined. In liquid propellant rockets, a turbopump is added. A hybrid rocket

combines liquid and solid propellant systems. Nonchemical rockets including

nuclear heating and electrically powered and electrothermal, electromagnetic, and

electrostatic thrusters are reviewed.

The book ends with 4 appendices. These lists chronicle details of piston,

turbojet, and turbofan engines, as well as milestones for rockets.

Finally, I would like to express my sincere appreciation and gratitude to Airbus

Industries and Rolls-Royce plc for their permission to use illustrations and photo-

graphs within this text.

I would like to express my sincere thanks to my editor, Charlotte Cross, who was

a great help since day one and continued her support during the tough time of

manuscript writing.

I’m deeply honored by the support of the dean and staff of Moscow Institute for

Physics and Technology (MIPT), Moscow University, and for granting me their

medal of 50th anniversary

Particular thanks for the continuous help and technical support of:

• Professor Darrell Pepper, Director, NCACM, University of Nevada Las Vegas,

USA

• Mr. Joseph Veres, Compressor Section, NASA Glenn Research Center, Cleve-

land, USA

• Professor Louis Chow, University of Central Florida, Orlando, USA

• Dr. Dennis Barbeau, AIAA Phoenix Section, USA

I would like to express my sincere thanks and utmost gratitude to my students:

Ahmed Z. Almeldein, Aerospace Department, Korea Advanced Institute of Science

and Technology, South Korea; Mohamed Aziz and Eslam Said Ahmed, Institute of

Aviation Engineering and Technology (IAET); Amr Kamel, Egyptian Air Force;

Mohamed Emera and Ibrahim Roufael, Mechanical Power Engineering

Preface xi

Department, Zagazig University; and Ahmed Hamed, Senior Production Engineer,

Engine Overhaul Directorate, EgyptAir Maintenance and Engineering Company.

At last, I extend my heartfelt gratitude to my wife, Amany, and sons Mohamed,

Abdallah, and Khalid who were the real inspiration and motivation behind

this work.

Zagazig, Egypt Ahmed F. El-Sayed

xii Preface

Contents

1 Classifications of Aircrafts and Propulsion Systems . . . . . . . . . . . . 1

1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1.2 Classifications of Aircrafts . . . . . . . . . . . . . . . . . . . . . . . . . . 3

1.2.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

1.2.2 Aerostats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

1.2.3 Aerodynes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

1.2.4 Fixed Wing Aircrafts . . . . . . . . . . . . . . . . . . . . . . . 5

1.2.5 Rotorcrafts (Rotor-Wing Aircrafts) . . . . . . . . . . . . . 31

1.2.6 Hybrid Fixed/Rotary Wings . . . . . . . . . . . . . . . . . . 44

1.2.7 Other Methods of Lift Aircrafts . . . . . . . . . . . . . . . 47

1.3 Classifications of Propulsion Systems . . . . . . . . . . . . . . . . . . 51

1.3.1 External Combustion . . . . . . . . . . . . . . . . . . . . . . . 51

1.3.2 Internal Combustion . . . . . . . . . . . . . . . . . . . . . . . 55

1.3.3 Other Power Sources . . . . . . . . . . . . . . . . . . . . . . . 78

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

2 A Review of Basic Laws for a Compressible Flow . . . . . . . . . . . . . 91

2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

2.2 System and Control Volume . . . . . . . . . . . . . . . . . . . . . . . . . 92

2.3 Fundamental Equations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

2.3.1 Conservation of Mass (Continuity Equation) . . . . . . 94

2.3.2 Linear Momentum (Newton’s Second Law) . . . . . . 96

2.3.3 Angular Momentum Equation (Moment

of Momentum) . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

2.3.4 Energy Equation (First Law

of Thermodynamics) . . . . . . . . . . . . . . . . . . . . . . . 106

2.3.5 The Second Law of Thermodynamics

and the Entropy Equation . . . . . . . . . . . . . . . . . . . . 110

2.3.6 Equation of State . . . . . . . . . . . . . . . . . . . . . . . . . . 111

xiii

2.4 Steady One-Dimensional Compressible Flow . . . . . . . . . . . . . 114

2.4.1 Isentropic Relations . . . . . . . . . . . . . . . . . . . . . . . . 114

2.4.2 Sonic Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . 116

2.4.3 Classification of Mach Regimes . . . . . . . . . . . . . . . 119

2.4.4 Diffusers and Nozzles . . . . . . . . . . . . . . . . . . . . . . 120

2.4.5 Shocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125

2.5 Rayleigh Flow Equations . . . . . . . . . . . . . . . . . . . . . . . . . . . 146

2.6 The Standard Atmosphere . . . . . . . . . . . . . . . . . . . . . . . . . . . 151

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160

3 Performance Parameters of Jet Engines . . . . . . . . . . . . . . . . . . . . . 161

3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161

3.2 Thrust Force . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162

3.3 Factors Affecting Thrust . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174

3.3.1 Jet Nozzle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175

3.3.2 Air Speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175

3.3.3 Mass Air Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175

3.3.4 Altitude . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176

3.3.5 Ram Effect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177

3.4 Engine Performance Parameters . . . . . . . . . . . . . . . . . . . . . . 178

3.4.1 Propulsive Efficiency . . . . . . . . . . . . . . . . . . . . . . . 179

3.4.2 Thermal Efficiency . . . . . . . . . . . . . . . . . . . . . . . . 186

3.4.3 Propeller Efficiency . . . . . . . . . . . . . . . . . . . . . . . . 189

3.4.4 Overall Efficiency . . . . . . . . . . . . . . . . . . . . . . . . . 189

3.4.5 Takeoff Thrust . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192

3.4.6 Specific Fuel Consumption . . . . . . . . . . . . . . . . . . . 193

3.4.7 Aircraft Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200

3.4.8 Range Factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205

3.4.9 Endurance and Endurance Factor . . . . . . . . . . . . . . 205

3.4.10 Mission Segment Weight Fraction . . . . . . . . . . . . . 206

3.4.11 Head- and Tail-Wind . . . . . . . . . . . . . . . . . . . . . . . 206

3.4.12 Route Planning . . . . . . . . . . . . . . . . . . . . . . . . . . . 209

3.4.13 Specific Impulse . . . . . . . . . . . . . . . . . . . . . . . . . . 213

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218

4 Piston Engines and Propellers . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219

4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219

4.2 Intermittent (or Piston) Engines . . . . . . . . . . . . . . . . . . . . . . . 221

4.2.1 Milestones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223

4.2.2 Types of Aero Piston Engines . . . . . . . . . . . . . . . . . 223

4.3 Aerodynamics and Thermodynamics

of Reciprocating ICE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232

4.3.1 Terminology for Four-Stroke Engine . . . . . . . . . . . 232

4.3.2 Air-Standard Analysis . . . . . . . . . . . . . . . . . . . . . . 233

4.3.3 Engine Cycles . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235

xiv Contents

4.4 Aircraft Propellers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261

4.4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261

4.4.2 Nomenclature . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264

4.5 Classifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265

4.5.1 Source of Power . . . . . . . . . . . . . . . . . . . . . . . . . . 265

4.5.2 Material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265

4.5.3 Coupling to the Output Shaft . . . . . . . . . . . . . . . . . 267

4.5.4 Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267

4.5.5 Number of Propellers Coupled to Each Engine . . . . 269

4.5.6 Direction of Rotation . . . . . . . . . . . . . . . . . . . . . . . 269

4.5.7 Propulsion Method . . . . . . . . . . . . . . . . . . . . . . . . . 271

4.5.8 Number of Blades . . . . . . . . . . . . . . . . . . . . . . . . . 271

4.6 Aerodynamic Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273

4.6.1 Axial Momentum, (or Actuator Disk) Theory . . . . . 274

4.6.2 Modified Momentum or Simple Vortex

Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281

4.6.3 Blade Element Considerations . . . . . . . . . . . . . . . . 282

4.7 Dimensionless Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . 287

4.8 Typical Propeller Performance . . . . . . . . . . . . . . . . . . . . . . . 293

4.9 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313

5 Pulsejet, Ramjet, and Scramjet Engines . . . . . . . . . . . . . . . . . . . . . 315

5.1 Introduction to Athodyd Engines . . . . . . . . . . . . . . . . . . . . . . 315

5.2 Pulsejet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315

5.2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315

5.2.2 Brief History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 316

5.2.3 Valved Pulsejet . . . . . . . . . . . . . . . . . . . . . . . . . . . 318

5.2.4 Thermodynamic Cycle . . . . . . . . . . . . . . . . . . . . . . 319

5.2.5 Valveless Pulsejet . . . . . . . . . . . . . . . . . . . . . . . . . 327

5.2.6 Pulsating Nature of Flow Parameters

in Pulsejet Engines . . . . . . . . . . . . . . . . . . . . . . . . . 329

5.2.7 Pulse Detonation Engine (PDE) . . . . . . . . . . . . . . . 330

5.3 Ramjet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337

5.3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337

5.3.2 Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 338

5.3.3 Aero-Thermodynamic Analysis of Modules . . . . . . 341

5.3.4 Aero-thermodynamic Analysis of Ramjet

Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 348

5.3.5 Nuclear Ramjet . . . . . . . . . . . . . . . . . . . . . . . . . . . 360

5.3.6 Double Throat Ramjet Engine . . . . . . . . . . . . . . . . 362

5.4 Scramjet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 364

5.4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 364

5.4.2 Evolution of Scramjets . . . . . . . . . . . . . . . . . . . . . . 365

5.4.3 Advantages and Disadvantages of Scramjets . . . . . . 367

5.4.4 Aero-Thermodynamic Analysis of Scramjets . . . . . . 367

Contents xv

5.4.5 Performance Analysis . . . . . . . . . . . . . . . . . . . . . . 371

5.4.6 Dual-Mode Combustion Engine

(Dual Ram-Scramjet) . . . . . . . . . . . . . . . . . . . . . . . 376

5.5 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 386

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 400

6 Turbine-Based Engines: Turbojet, Turbofan, and Turboramjet

Engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 403

6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 403

6.2 Turbojet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 404

6.2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 404

6.2.2 Milestones of Turbojet Engines . . . . . . . . . . . . . . . 407

6.2.3 Thermodynamic Cycle Analysis of a Single

Spool . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 407

6.2.4 Performance Parameters of a Single Spool . . . . . . . 416

6.2.5 Important Definitions . . . . . . . . . . . . . . . . . . . . . . . 417

6.2.6 Double-Spool Turbojet . . . . . . . . . . . . . . . . . . . . . . 430

6.2.7 Thermodynamic Analysis of Double-Spool

Turbojet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 430

6.2.8 Performance Parameters of Double-Spool

Turbojet Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . 435

6.2.9 Micro-turbojet . . . . . . . . . . . . . . . . . . . . . . . . . . . . 441

6.3 Turbofan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 445

6.3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 445

6.3.2 Milestones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 446

6.3.3 Classifications of Turbofan Engines . . . . . . . . . . . . 446

6.3.4 Forward Fan Unmixed Double-Spool

Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . 448

6.3.5 Forward Fan Mixed-Flow Engine . . . . . . . . . . . . . . 461

6.3.6 Forward Fan Unmixed Three-Spool Engine . . . . . . . 471

6.4 Turbine-Based Combined-Cycle (TBCC) Engines . . . . . . . . . 479

6.4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 479

6.4.2 Historical Review of Supersonic and Hypersonic

Aircrafts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 481

6.4.3 Technology Challenges of the Future Flight . . . . . . 486

6.4.4 Propulsion System Configurations . . . . . . . . . . . . . . 486

6.4.5 Performance of TBCC (or Hybrid Engine) . . . . . . . 490

6.4.6 Cycle Analysis of Turboramjet (or TBCC)

Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 492

6.4.7 General Analysis for a Turboramjet Engine . . . . . . . 498

6.4.8 Design Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . 508

6.4.9 Future TBCC Engine . . . . . . . . . . . . . . . . . . . . . . . 509

6.5 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 509

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 528

xvi Contents

7 Shaft Engines Turboprop, Turboshaft, and Propfan . . . . . . . . . . . 531

7.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 531

7.2 Turboprop Engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 532

7.2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 532

7.2.2 Milestones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 534

7.2.3 Thermodynamics Analysis of Turboprop

Engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 538

7.2.4 Equivalent Engine Power . . . . . . . . . . . . . . . . . . . . 545

7.2.5 Fuel Consumption . . . . . . . . . . . . . . . . . . . . . . . . . 546

7.2.6 Analogy with Turbofan Engines . . . . . . . . . . . . . . . 552

7.3 Turboshaft . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 553

7.3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 553

7.3.2 Examples for Turboshaft Manufacturers

and Engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 553

7.3.3 Thermodynamic Analysis of Turboshaft Engines . . . 556

7.3.4 Power Generated by Turboshaft Engines . . . . . . . . . 557

7.4 Propfan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 564

7.4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 564

7.4.2 Historical Hints . . . . . . . . . . . . . . . . . . . . . . . . . . . 565

7.4.3 Classifications of Propfans . . . . . . . . . . . . . . . . . . . 567

7.4.4 Comparisons Between Turboprop, Propfan,

and Turbofan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 569

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 587

8 Stationary Modules Intakes, Combustors, and Nozzles . . . . . . . . . 589

8.1 Intake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 589

8.1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 589

8.1.2 Power Plant Installation . . . . . . . . . . . . . . . . . . . . . 590

8.1.3 Inlet Performance Parameters . . . . . . . . . . . . . . . . . 619

8.1.4 Subsonic Intakes . . . . . . . . . . . . . . . . . . . . . . . . . . 621

8.1.5 Supersonic Intakes . . . . . . . . . . . . . . . . . . . . . . . . . 637

8.1.6 Hypersonic Inlets . . . . . . . . . . . . . . . . . . . . . . . . . . 645

8.1.7 Performance Parameters . . . . . . . . . . . . . . . . . . . . . 646

8.2 Combustion Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 653

8.2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 653

8.2.2 Types of Combustion Chamber . . . . . . . . . . . . . . . . 653

8.2.3 Components of Combustion Chamber . . . . . . . . . . . 658

8.2.4 Aerodynamics of Combustion Chamber . . . . . . . . . 661

8.2.5 The Chemistry of Combustion . . . . . . . . . . . . . . . . 665

8.2.6 The First Law Analysis of Combustion . . . . . . . . . . 668

8.2.7 Combustion Chamber Performance . . . . . . . . . . . . . 669

8.2.8 Material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 672

8.2.9 Aircraft Fuels . . . . . . . . . . . . . . . . . . . . . . . . . . . . 672

8.2.10 Emissions and Pollutants . . . . . . . . . . . . . . . . . . . . 674

8.2.11 Afterburner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 675

Contents xvii

8.3 Exhaust Nozzle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 677

8.3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 677

8.3.2 Operation of Nozzles . . . . . . . . . . . . . . . . . . . . . . . 680

8.3.3 Performance Parameters of Nozzles . . . . . . . . . . . . 681

8.3.4 High-Speed Vehicles . . . . . . . . . . . . . . . . . . . . . . . 689

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 700

9 Centrifugal and Axial Compressors . . . . . . . . . . . . . . . . . . . . . . . . 703

9.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 703

9.2 Centrifugal Compressor . . . . . . . . . . . . . . . . . . . . . . . . . . . . 703

9.2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 703

9.2.2 Layout of Compressor . . . . . . . . . . . . . . . . . . . . . . 706

9.2.3 Classification of Centrifugal Compressors . . . . . . . . 708

9.2.4 Governing Equations . . . . . . . . . . . . . . . . . . . . . . . 711

9.2.5 Slip Factor (σ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 718

9.2.6 Types of Impeller . . . . . . . . . . . . . . . . . . . . . . . . . 724

9.2.7 Impeller Isentropic Efficiency . . . . . . . . . . . . . . . . . 728

9.2.8 Radial Impeller . . . . . . . . . . . . . . . . . . . . . . . . . . . 733

9.2.9 Diffuser . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 735

9.2.10 Prewhirl . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 737

9.2.11 Discharge System . . . . . . . . . . . . . . . . . . . . . . . . . 742

9.2.12 Compressor Map . . . . . . . . . . . . . . . . . . . . . . . . . . 742

9.2.13 Surge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 746

9.3 Axial Flow Compressor . . . . . . . . . . . . . . . . . . . . . . . . . . . . 747

9.3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 747

9.3.2 Comparison Between Axial and Centrifugal

Compressors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 750

9.3.3 Mean Flow (Two-Dimensional Approach) . . . . . . . . 752

9.3.4 Basic Design Parameters . . . . . . . . . . . . . . . . . . . . 763

9.3.5 Design Parameters . . . . . . . . . . . . . . . . . . . . . . . . . 770

9.3.6 Real Flow in Axial Compressor . . . . . . . . . . . . . . . 773

9.3.7 Simplified Radial Equilibrium Equation (SRE) . . . . 775

9.3.8 Conceptual Design Procedure for Axial

Compressor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 794

9.3.9 Blade Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 808

9.3.10 Choice of Airfoil Type . . . . . . . . . . . . . . . . . . . . . . 812

9.3.11 Compressor Map . . . . . . . . . . . . . . . . . . . . . . . . . . 813

9.4 Centrifugal and Axial Compressors Material . . . . . . . . . . . . . 818

9.5 Closure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 819

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 837

10 Turbines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 839

10.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 839

10.2 Axial Flow Turbines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 840

10.2.1 Flow Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . 840

10.2.2 Euler Equation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 841

xviii Contents

10.2.3 Efficiency and Pressure Ratio . . . . . . . . . . . . . . . . . 843

10.2.4 Loss Coefficients in Nozzle and Rotor . . . . . . . . . . 845

10.2.5 Performance Parameters . . . . . . . . . . . . . . . . . . . . . 846

10.2.6 Free Vortex Design . . . . . . . . . . . . . . . . . . . . . . . . 858

10.2.7 Turbine Cooling Techniques . . . . . . . . . . . . . . . . . . 867

10.2.8 Guide Lines for Axial Turbine Design . . . . . . . . . . 870

10.2.9 Turbine Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 872

10.3 Radial Flow Turbine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 873

10.3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 873

10.3.2 Aero-Thermodynamics of Radial Inflow

Turbine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 873

10.3.3 Recommended Design Values for Radial Inflow

Turbines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 879

10.3.4 Radial Versus Axial Turbines . . . . . . . . . . . . . . . . . 880

10.4 Gas Turbine Engine Matching . . . . . . . . . . . . . . . . . . . . . . . . 885

10.4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 885

10.4.2 Compatibility Conditions . . . . . . . . . . . . . . . . . . . . 885

10.4.3 Single Shaft Gas Turbine Engine . . . . . . . . . . . . . . 886

10.4.4 Off-Design of Free Turbine Engine . . . . . . . . . . . . . 888

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 905

11 Rocket Propulsion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 907

11.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 907

11.2 History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 908

11.2.1 Important Events . . . . . . . . . . . . . . . . . . . . . . . . . . 908

11.2.2 Future Plans of Rocket and Space Flights

(2014 and Beyond) . . . . . . . . . . . . . . . . . . . . . . . . 912

11.3 Classifications of Rockets . . . . . . . . . . . . . . . . . . . . . . . . . . . 912

11.3.1 Method of Propulsion . . . . . . . . . . . . . . . . . . . . . . . 912

11.3.2 Types of Missiles . . . . . . . . . . . . . . . . . . . . . . . . . . 912

11.3.3 Launch Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 913

11.3.4 Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 914

11.3.5 Number of Stages . . . . . . . . . . . . . . . . . . . . . . . . . 914

11.3.6 Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 914

11.4 Rocket Performance Parameters . . . . . . . . . . . . . . . . . . . . . . 914

11.4.1 Thrust Force . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 915

11.4.2 Effective Exhaust Velocity (Veff) . . . . . . . . . . . . . . 915

11.4.3 Exhaust Velocity (ue) . . . . . . . . . . . . . . . . . . . . . . . 919

11.4.4 Important Nozzle Relations . . . . . . . . . . . . . . . . . . 920

11.4.5 Characteristic Velocity (C*) . . . . . . . . . . . . . . . . . . 922

11.4.6 Thrust Coefficient (CF) . . . . . . . . . . . . . . . . . . . . . 922

11.4.7 Total Impulse (It) . . . . . . . . . . . . . . . . . . . . . . . . . . 924

11.4.8 Specific Impulse (Isp) . . . . . . . . . . . . . . . . . . . . . . . 924

11.4.9 Specific Propellant Consumption . . . . . . . . . . . . . . 929

11.4.10 Mass Ratio (MR) . . . . . . . . . . . . . . . . . . . . . . . . . . 929

Contents xix

11.4.11 Propellant Mass Fraction (ζ) . . . . . . . . . . . . . . . . . . 929

11.4.12 Impulse-to-Weight Ratio . . . . . . . . . . . . . . . . . . . . 930

11.4.13 Efficiencies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 930

11.5 The Rocket Equation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 933

11.5.1 Single-Stage Rocket . . . . . . . . . . . . . . . . . . . . . . . . 933

11.5.2 Multistage Rockets . . . . . . . . . . . . . . . . . . . . . . . . 937

11.5.3 Rocket Equation for a Series Multistage

Rocket . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 938

11.5.4 Rocket Equation for a Parallel Multistage

Rocket . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 940

11.5.5 Advantages of Staging . . . . . . . . . . . . . . . . . . . . . . 940

11.5.6 Disadvantages of Staging . . . . . . . . . . . . . . . . . . . . 941

11.6 Chemical Rocket Engines . . . . . . . . . . . . . . . . . . . . . . . . . . . 945

11.6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 945

11.6.2 Performance Characteristics . . . . . . . . . . . . . . . . . . 945

11.7 Solid Propellant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 946

11.7.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 946

11.7.2 Composition of a Solid Propellant . . . . . . . . . . . . . 948

11.7.3 Basic Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . 949

11.7.4 Burning Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 950

11.7.5 Characteristics of Some Solid Propellants . . . . . . . . 958

11.8 Liquid-Propellant Rocket Engines (LREs) . . . . . . . . . . . . . . . 959

11.8.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 959

11.8.2 Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 960

11.8.3 Propellant Feed System of LREs . . . . . . . . . . . . . . 961

11.8.4 Liquid Propellants . . . . . . . . . . . . . . . . . . . . . . . . . 962

11.8.5 Fundamental Relations . . . . . . . . . . . . . . . . . . . . . . 965

11.8.6 Pump-Fed System . . . . . . . . . . . . . . . . . . . . . . . . . 968

11.8.7 Rocket Pumps . . . . . . . . . . . . . . . . . . . . . . . . . . . . 972

11.8.8 Pump Materials and Fabrication Processes . . . . . . . 973

11.8.9 Axial Turbine . . . . . . . . . . . . . . . . . . . . . . . . . . . . 974

11.9 Hybrid Propulsion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 976

11.9.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 976

11.9.2 Mathematical Modeling . . . . . . . . . . . . . . . . . . . . . 978

11.9.3 Advantages and Disadvantages of Hybrid

Engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 980

11.10 Nuclear Rocket Propulsion . . . . . . . . . . . . . . . . . . . . . . . . . . 981

11.11 Electric Rocket Propulsion . . . . . . . . . . . . . . . . . . . . . . . . . . 982

11.11.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 982

11.11.2 Electrostatic Rockets . . . . . . . . . . . . . . . . . . . . . . . 983

11.11.3 Electrothermal Rockets . . . . . . . . . . . . . . . . . . . . . 983

11.11.4 Electromagnetic Rockets . . . . . . . . . . . . . . . . . . . . 984

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 990

xx Contents

Appendices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 993

Appendix A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 993

Appendix B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 994

Appendix C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 996

Appendix D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 999

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1003

Contents xxi