Gas Turbine Performance Second Edition Philip P. Walsh BSc, FRAeS, CEng Head of Performance and Engine Systems Rolls-Royce plc Paul Fletcher MA (Oxon), MRAeS, CEng Manager, Prelim Design Energy Business Rolls-Royce plc https://boilersinfo.com # 1998, 2004 by Blackwell Science Ltd First published 1998 a Blackwell Publishing company Reprinted 1998, 1999, 2000 (twice) Second edition 2004 Editorial Offices: Blackwell Science Ltd, 9600 Garsington Road, Library of Congress Cataloging-in-Publication Oxford OX4 2DQ, UK Data Tel: þ44 (0) 1865 776868 Blackwell Publishing Inc., 350 Main Street, Walsh, Philip P. Malden, MA 02148-5020, USA Gas turbine performance / Philip P. Walsh, Paul Tel: þ1 781 388 8250 Fletcher. – 2nd ed. Blackwell Science Asia Pty, 550 Swanston Street, p. cm. Carlton, Victoria 3053, Australia Includes bibliographical references and index. Tel: þ61 (0)3 8359 1011 ISBN 0-632-06434-X (alk. paper) 1. Gas-turbines–Performance. I. Fletcher, Paul. The right of the Author to be identified as the II. Title. Author of this Work has been asserted in accordance with the Copyright, Designs and TJ778.W36 2004 0 Patents Act 1988. 621.48 3–dc22 2003063655 All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or ISBN 0-632-06434-X transmitted, in any form or by any means, electronic, mechanical, photocopying, recording A catalogue record for this title is available from or otherwise, excepted as permitted by the the British Library UK Copyright, Designs and Patents Act 1988, without the prior permission of the publisher. Set in 9/11 pt Times by Aarontype Limited, Bristol Printed and bound in India using acid-free paper by Thomson Press (I) Ltd, India For further information on Blackwell Publishing, visit our website: www.blackwellpublishing.com https://boilersinfo.com Foreword to the first edition Sir Frank Whittle first ran his jet engine in April 1937 since when the gas turbine has had an immeasurable impact upon society. Today there are few people in the developed world whose daily life is not touched by it. The ready access to global air travel, low cost electricity, natural gas pumped across continents, and the defence of nations both in the air and at sea are but a few of the things so many of us take for granted which depend upon gas turbine power. Those involved in the design, manufacture and operation of gas turbines over the last 60 years have made enormous strides. Today the largest turbofans produce 100 times the thrust of the Whittle and von Ohain engines, the latter having made the first flight of a gas turbine in August 1939. The challenge for the forthcoming decades will be undiminished with ever increasing demands to minimise pollution and energy consumption to preserve a better world for the next generation. There will be a continued drive for lower cost of operation, and the opening up of new applications such as mass produced automotive propulsion. The chal- lenges are not just technical, but include adapting to a changing working environment. For example, since I joined the gas turbine industry some 35 years ago computers have revolu- tionised working practices. Indeed it is not possible to design today’s gas turbines without the use of the very latest computational technology, whilst the authors have fully embraced ‘best practice’ in desk top publishing to make this textbook possible. For those of us fortunate enough to face these challenges ‘gas turbine performance’ is our cornerstone. It is what our customers purchase and hence is our raison d’eˆtre. It is the functional integration, or marriage, of all elements of gas turbine technology into a product. No matter what role we may have we must understand it, and cannot afford to lose sight of it. This book is longhttps://boilersinfo.com overdue. It is written in a clear, applied and digestible fashion and will be of benefit to engineers in all phases of their careers. It admirably describes the fundamentals of gas turbine performance and whole engine design for those who have not yet encountered them, while providing an abundance of reference material for those who are more advanced. It also describes all gas turbine configurations and applications. This is particularly valuable because another facet of change in our industry is that engineers are unlikely to continue their careers concentrating on only aero, or industrial and marine engines. The investment in technology is so great that it must be amortised over a wide product base, hence there are few gas turbine companies that are not in some way involved in all market sectors. I am sure that this book will be of great benefit to you in whatever part you play in our industry. I hope your involvement with gas turbines is as enjoyable as mine has been, and is today. Philip C. Ruffles Director of Engineering and Technology Rolls-Royce plc, Derby, UK Preface Performance is the end product that a gas turbine company sells. Furthermore, it is the thread which sews all other gas turbine technologies together. Gas turbine performance may be summarised as: The thrust or shaft power delivered for a given fuel flow, life, weight, emissions, engine diameter and cost. This must be achieved while ensuring stable and safe operation throughout the operational envelope, under all steady state and transient conditions. To function satisfactorily within a gas turbine company, engineers from all disciplines, as well as marketing staff, must understand the fundamentals of performance. The authors were motivated to write this book by experiences gained while working for three prominent gas turbine companies in the UK and the USA. These clearly showed the pressing need for a book presenting the fundamentals of performance in an applied manner, pertinent to the everyday work of those in industry as well as university based readers. The strategy adhered to in writing this book, together with some of its unique features, are described below: . The main text contains no algebra and is laid out in a manner designed for easy reference. The latter is achieved by careful section numbering, the use of bullet points, extensive figures, charts and tables, and by deferring the more difficult concepts to the end of sections or chapters. Comprehensive lists of formulae, together with sample calculations are located at the end of each chapter. Formulae are presented in FORTRAN/BASIC/Spreadsheet format for ease of implementationhttps://boilersinfo.com in PC programs. The lead unit system employed is SI. However key unit conversions are provided on every figure, chart and table catering for the needs of all readers world-wide. Furthermore, a comprehensive list of unit conversions is supplied as an appendix. The internationally recognised aerospace recommended practice for nomenclature and engine station numbering laid down in ARP 755A is listed as an appendix, and employed throughout. Figures, charts, tables and formulae provide not only trends and the form of relationships, but also a database for design purposes. Charts are located at the end of each chapter, whereas figures are embedded in the text. Also practical guidelines for engine design are provided throughout the text. All aspects of gas turbine performance are covered, with chapters on topics not easily found in other textbooks such as transient performance, starting, windmilling, and analysis of engine test data. All gas turbine engine variants are discussed, including turbojets, turbofans, turboprops, turboshafts, auxiliary power units and ramjets. xiv Preface . An introduction to gas turbine applications is provided in Chapter 1. Subsequent chapters address meeting the various requirements particular to all major applications such as power generation, mechanical drive, automotive, marine and aircraft installations. The importance of dimensionless and other parameter groups in understanding the fundamentals of gas turbine performance is emphasised throughout. Component performance and design is presented from an engine performance viewpoint. A comprehensive list of references is provided for those wishing to pursue detailed component aero-thermal and mechanical design issues. This book is primarily aimed at engineers of all disciplines within the gas turbine industry, and will also be of significant value to students of mechanical and aeronautical engineering. It should also appeal to people outside the industry who have an interest in gas turbines. Experienced engineers will particularly welcome the database and list of formulae which it is hoped will make the book an invaluable reference tool. The guidelines, charts and formulae provided should be invaluable for instructive or ‘scoping’ purposes, particularly where simplified forms are shown to ease implementation. Progression of projects beyond this must always be accompanied by an appropriate quality plan, however, including stringent control of the accuracy of any software produced. As such, no liability can be accepted for the consequences of any inaccuracies herein. For the second edition all existing chapters have been reviewed, and a range of minor improvements and alterations introduced. Also, two new chapters have been added covering performance issues relating to engines ‘in-service’, and also the economics of gas turbines. In recent years the inexorable drive to lower operating costs has increased the need to understand both in-service performance, via issues such as health monitoring, and also the ‘techno-economic’ issues that determine whether or not a gas turbine project will be profitable. The authors acknowledge the significant contribution made to this book by their wives. Mrs Mary Fletcher has made a considerable technical input, while Mrs Maria Walsh has provided secretarial support. Our thanks are extended to all of our colleagues and friends from whom we have learned so much. It is impossible to list them all here, however it would not be fitting if the late Mr Robert Chevis were not mentioned by name. He was a source of immense inspiration to both authors, as well as a fountain of knowledge.