Table Of Content

[email protected] rodvna An account of the mechanics of flow in and around the air intakes of turbine-engined and ramjet aircraft and missiles J. Seddon and E. L. Goldsmith COLLINS 8 Grafton Street, London W1 [email protected] Collins Professional and Technical Books William Collins Sons & Co. Ltd 8 Grafton Street, London W1X 3LA First published in Great Britain by Collins Professional and Technical Books 1985 Copyright (Q John Seddon and E.L. Goldsmith 1985 British Library Cataloguing in Publication Data Seddon, J. Intake aerodynamics: an account of the mechanics of flow in and around the air intakes of turbine-engined and ramjet aircraft and missiles. 1. Airplanes-Hydraulic equipment 2. Intakes (Hydraulic engineering) 3. Airflow I. Title 11. Goldsmith, E.L. 629.132'32 TL697. H9 ISBN 0-00-383048-9 Printed and bound in Great Britain by Mackays of Chatham, Kent All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted, in any form, or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior permission of the publishers. Intake Aerodynamics Contents Foreword xii Preface xiv Acknowledgements xviii Notation List xix List of Abbreviations xxviii Chapter 1: Introductory 1.1 Useful flow relationships 1.2 Incompressible flow 1.3 Momentum theorem 1.4 Aerodynamic duct concept 1.5 Flow quantity through an aerodynamic duct 1.6 Intake pressure recovery 1.7 Intake drag: compromise in design Chapter 2: Pressure Recovery of Subsonic Intakes Introduction Collected data Approximate theory of friction loss Examination of ,u3v ariation Systematic research on diffusers Pressure recovery characteristics Plenum chambers vi CONTENTS 2.8 Propeller turbines 2.9 Flowstabilityin twinintakes 2.10 Helicopter intakes Chapter 3: Transonic Effects in Pre-entry Flow 3.1 First expectations 3.2 Experiments of Davis et al. 3.3 Real nature of pre-entry flow 3.4 Pressure coefficient at separation 3.5 Effect of separation on intake pressure recovery 3.6 Basics of normal shock and turbulent boundary-layer interaction Chapter 4: Lip Separation and Transonic Throat Flow 4.1 Introduction 4.2 Calculation methods 4.3 Transonic throat flow with AJA, < 1 4.4 Lip shaping for AJA, > 1 4.5 Prediction of total-pressure loss 4.5.1 Attached flow at entry 4.5.2 Separated flow at entry 4.5.3 Special conditions with separated flow 4.6 Static loss in practical intakes Chapter 5: External Supersonic Compression 5.1 Pitot intake 5.2 Two-shock intakes 5.3 Multi-shock intakes 5 -4 Isentropic compression 5.5 Limits of external compression 5.5.1 External shock attachment with no duct angling 129 CONTENTS vii 5.5.2 Internal shock attachment 5.5 -3 Shock structure Intakes A and B Position of normal shock in subcritical operation 5.7.1 Pitot intake 5.7.2 Two-shock intakes Calculation of subcritical pressure recovery Chapter 6: Internal Supersonic Compression Flow starting problem Limiting contraction ratio Perforated intake Variable geometry for flow starting Types of intake and limiting pressure recovery Mixed compression: intakes C and D Some design, performance and operating aspects Chapter 7: Additional Loss in Supersonic Intakes Introduction Pitot intake Side intake External-compression intakes: adaptation of interaction formula Empirical analysis of 'cornering losses' for axisymmetric intakes Inviscid theory for special case of cylindrical cowl Situation with two-dimensional intakes Chapter 8: Boundary Layer Bleeds and Diverters 8.1 Brief description 8.2 Parameters relevant to intake performance .. . Vlll CONTENTS 8.3 Removal of aircraft boundary layer 8.3.1 Normal-shock intakes 8.3- 2 External-compression intakes 8.4 Compression-surface bleeds 8.4.1 External compression 8.4.2 Internal or mixed compression 8.5 Bleed drag 8.5.1 Typesofflow 8.5.2 Application of momentum equation 8.6 Diverter drag Chapter 9: Intake External Drag 9.1 Introduction 9.2 Definitions of thrust and drag 9.3 Subsonic intake drag below critical Mach number 9.4 Cowl design for high drag-rise Mach number 9.4.1 Subcritical design 9.4 -2 Supercritical design 9.5 Spillage drag 9.5.1 General considerations 9.5.2 Pitot intake at subsonic speeds 9.5.3 Pitot intake at transonic speeds 9.5.4 Pitot intake at supersonic speeds 9.5.5 Methods of prediction 9.5 -6 External-compression intakes 9.6 Cowl pressure drag 9.6.1 Axisymmetric sharp-lipped cowls 9.6.2 Two-dimensional sharp-lipped cowls 9.6.3 Blunt-lipped cowls Chapter 10: Shock Oscillation of Supersonic Intakes 10.1 Introduction CONTENTS 10.2 General description 10.3 Buzz initiation 10.3.1 Vortex-sheet (Ferri) criterion 10.3.2 Flow separation from compression surface 10.3.3 Pressure-slope criterion 10.3.4 Dynamic stability theories 10.4 Buzz avoidance 10.5 Other forms of shock oscillation Chapter 11: Distortion and Swirl Introduction and historical note Total-pressure distortion 11.2.1 Criteria in steady flow 11.2.2 Dynamic distortion 11.2.3 Intake considerations Swirl 11.3.1 Intrinsic nature of flow 11.3.2 Sensitivities and correlation potential Chapter 12: Matching and Control 12.1 Subsonic intake 12.2 Supersonic intake: nature of the problem 12.3 Supply and demand 12.4 Variable geometry and practical examples 12.5 Additional complexities: a case in point 12.5.1 The Concorde intake 12.5.2 Matching in high-speed flight 12.5- 3 Transients 12.6 Matching of a ramjet intake