Benjamin Gal-Or

Vectored Propulsion, Supermaneuverability and Robot Aircraft

With 190 Figures

Springer-Verlag New York Berlin Heidelberg London Paris Tokyo Hong Kong Professor Benjamin Gal-Or Technion-Israel Institute of Technology Department of Aeronautical Engineering 32000 Haifa Israel

Library of Congress Cataloging-in-Publication Data Gal-Or, Benjamin. Vectored propulsion, supermaneuverability, and robot aircraft / by Benjamin Gal-Or. P. em. I. Airplanes - Jet propulsion. 2. Drone aircraft. 3. Jet planes, Military. 4. stealth aircraft. I. Title. TL685.3.G23 1989 629. I 34'353-dc20 89-21797

© 1990 by Benjamin Gal-Or All rights reserved. This work may not be translated or copied in whole or in part without the written permission of the copyright holder, except for brief excerpts in connection with reviews or scholarly analysis. Use in connection with any form of information storage and retrieval, elec• tronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed is forbidden. The use of general descriptive names, trade names, trademarks, etc. in this publication, even if the former are not especially identified, is not to be taken as a sign that such names, as under• stood by the Trade Marks and Merchandise Marks Act, may accordingly be used freely by anyone.

Typeset, Printed, and Bound by Keterpress, Jerusalem, Israel

ISBN-13: 978-0-387-97161-2 e-ISBN-13: 978-1-4613-8961-3 DOl: 10.1007/978-1-4613-8961-3 Dedicated to my family; Leah, Amir and Gillad, who, by their respective professions, and by their encouragement, have given me invaluable help in preparing this volume, and to the members of the Jet Propulsion Laboratory Team, Azar, B.; Cohen, Z.; Dekel, E.; Friedman, E.; Golijow, E.; Mashiach, E.; Rasputnis, A.; Soreq, I.; Turgemann M.; and Vorobeichik, S., to whom I am greatly indebted. Mistakes!, Who may pretend to comprehend them? And for the unknown ones, please forgive me." Based on Psalms 19:12

"Our whole problem is to make the mistakes as fast as possible ..." John Archibald Wheeler

"All our knowledge grows only through the correcting of our mistakes." The Philosopher of Science Sir Karl R. Popper

(Conjectures and Refutations; The Growth of Scientific Knowledge, K.R. Popper, Routledge and Kegan Paul, Lon• don, 1972). Foreword

With the advent of digital flight control and digital engine control technologies, airframe and propulsion systems designers can now consider a much higher degree of coupling between the aircraft and its engine than ever before to achieve revolutionary new capabilities for high performance aircraft. Professor Gal-Or's landmark book is, in my opinion, the most complete and definitive treatment to date of the complex aerodynamic and control integration associated with vectored-thrust propulsion, aircraft agility enhanced by multi-axis thrust vectoring and reaction control systems, and provides valuable insight into applications for piloted and robotic aircraft. Although the military utility of enhanced agility using vectored propulsion is not fully understood, it is clear that a better experimental and analytical technology base is necessary to evaluate the concepts in realistic air combat scenarios. Professor Gal-Or's book is a valuable reference in this regard, although the reader should be cautioned that a text on such a rapidly-developing field may need to be updated as new information becomes available. Professor Gal~Or addresses the key questions in the Introduction, which are the subject of active research and development programs in all major aerospace establishments. The above comments should not be interpreted as an endorsement ofthis book, or its contents, by the United States Air Force.

Dr. G. KEITH RICHEY Technical Director of the Wright Research and Development Center, Wright-Patterson Air Force Base, Ohio, USA TABLE OF CONTENTS

G. Keith Richey: Foreword ...... 5 Preface ...... 9 Acknowledgements ...... 15 Glossary and Notation...... 17

Introduction ...... 21

The main problems of thrust-vectored maneuverability • Vectored Aircraft: Breaking the "Stall Barrier" • The New Standard Technology • Civil Appli- cations...... 25 Soviet and Western Concepts • Research tools • Cold propulsion • The Fundamental Definitions of Pure Vectored Aircraft (PVA) ...... 29 Pure Sideslip Maneuvers (PSM) • Combat Applications • ...... 30 Partially-Vectored Aircraft ...... 33 Agility, Supermaneuverability and Supercontrollability ...... 34 Load factors ...... 38 "Energy" Vs. "Angles" Fights • Time Lags • ...... 40 The Overall Combat Picture ...... 43 Minimum Time Turns • Low Observability • Stealth RPVs ...... 49 The Time Gaps ...... 50 New Educational Shifts...... 52 Concluding Remarks 53

Lecture I: Fundamental Concepts Revisited and Redefined ...... 56

New Missions and Modified Design Trends ...... 57 Early Conceptual Design Limitations ...... 58 Internal Thrust Vectoring ...... 59 Engine Nozzle Redefined ...... 62 Performance Comparisons ...... 69 Subsonic Yaw-Pitch-Roll Thrust Vectoring ...... 71 vii

Lecture II: Vectored Aircraft and Supermaneuverability 78 Yaw-Pitch Vectoring and Supercirculation ...... 78 Pure Jetborne Flight Control ...... 81 STOL or V/STOL Vectored Aircraft ...... 82 Dimensionless Numbers for Pure Vectored Aircraft ...... 83 Emergency Landing ...... 88 Air-to-Air Operations ...... 91 Air-to-Ground Operations...... 92 Propulsion and Supermaneuverability ...... 92 Maneuver Analysis...... 95 Controllability Limits...... 97 High-Alpha Flight Envelopes ...... 102 The Non-Availability of a "Vectored Inlet" ...... 104

Lecture III: The Matrix of Unknown Variables of Vectored Aircraft 105 Reservations and Precautions ...... 106 Technology Limits ...... 107 Cooling Limits ...... 109 Nozzle Aspect Ratio Limits ...... 114 Aerodynamic Effects ...... 115 Nozzle Coefficients Revisited ...... 125 Thrust Vectoring Range ...... 128 Induced drag and Supercirculaton ...... 130

Lecture IV: Vectored Aircraft as R&D Tools, or as Super-Agile Robotic Flying Systems 133 Cruise Missiles, RPV s, etc...... 134 Expanded Missions Vs. R&D tools ...... 136 Cost-Effectiveness of Flying Vectored RPV s ...... 139 Synergetic Studies...... 145 Master Plan and New Programs ...... 151 Scaling Consideratons ...... 153

Lecture V: Partially Vectored Aircraft ...... 155 Canard-Configured Vectored Aircraft ...... 156 Upgrading extant Aircraft to Become Vectored Fighters - The Vectored F-15 Fighter ...... 163 viii

Upgrading F-18 and F-16 Fighters...... 167 The Search for Design Philosophy in the Post-A TF Era ...... 168

Lecture VI: The Pros and Cons of Internal Thrust Vectoring ...... 177 Is ETV Effective in the RaNPAS-PST Domain? ...... 178 The Propulsion System of the Vectored X-31, X-29, etc...... 181 Stability and Flight Control ...... 184 Power-Lift Aircraft ...... 186

Appendix A: A Brief Historical Survey...... 188 Appendix B: Powerplant Technology Limits ...... 194 Beyond the Year 2000/RCC/STOVL ...... 194 Current-Technology Limits and Trends...... 203 Whole-System Engineering Approach ...... 209 European Fighter Engines ...... 209 New Fighter Engines: The ATF and Other New Engines ...... 210 The MiG-29 and Su-27 Propulsion Systems ...... 211 Variable Cycle, Turbine Bypass, and Supersonic-Fan Engines ...... 212

Appendix C: Nozzle Performance (Data-Base-l] Appendix D Nozzle Synergetic Effects (Data-Base-2] Appendix E: Temperature Distribution Test Facility...... 236 Appendix F: Limiting Engine-Inlet Envelopes and IFPC ...... 240 PST Inlet Design...... 243 IFPC Transient Definitions 244 Appendix G: On Some Other Vectored/Stealth Aircraft Consideratons ...... 251 Appendix H: Thought-Provoking and Thought-Depressing Quotations ...... 251 References ...... 259 Index...... 271