COMMERCIALIZATION AND TRANSFER OF TECHNOLOGY IN THE U.S. JET AIRCRAFT ENGINE INDUSTRY by Jerry R. Sheehan S.B. Electrical Engineering Massachusetts Institute of Technology 1986 Submitted to the Department of Aeronautics and Astronautics in Partial Fulfillment of the Requirements for the Degree of MASTER OF SCIENCE in Technology and Policy at the Massachusetts Institute of Technology June 1991 o Massachusetts Institute of Technology, 1991. All Rights Reserved. Signature of Author Department of Aeronautics & Astronautics May 10,1991 Certified by: Theodore A. Postol Professor of Science, Technology, and National Security Thesis Supervisor Certified by: •, . .. lr • . .. • _• . ..._. ... ., •- _... .. /I" VPtofessor Richard de Neufville Chair, Technology and Policy Program *1 Accepted by: -- -- Professor Harold Y. Wachman L/ Chairman, Department Graduate Committee MASAC-US~1TS I~NSTi E OF TECHCnt. aGy JUN L• 1991 LtHAHIES COMMERCIALIZATION AND TRANSFER OF TECHNOLOGY IN THE U.S. JET AIRCRAFT ENGINE INDUSTRY by Jerry R. Sheehan Submitted to the Department of Aeronautics and Astronautics on May 10, 1991 in partial fulfillment of the requirements for the degree of Master of Science in Technology and Policy ABSTRACT This thesis examines the changing nature of technology transfer between military and commercial research and development programs inthe U.S. jet aircraft engine industry. Early technology transfer in the jet engine industry is shown to have been characterized by the direct commercialization of military engines. Future technology transfer is projected to consist of the transfer of basic research results from military to commercial programs. As a result, it is argued, the military can be expected to assume less of the cost and risk associated with the development of future commercial engines than it formerly did. Prospects for future technology transfer are evaluated by determining the types of engines likely to be developed for military and commercial aircraft. The effects of increased specific thrust and improved fuel economy upon aircraft range, speed, and fuel consumption are demonstrated by analyzing the aerodynamic performance of military fighter, bombers, and transports and of commercial airliners. The technologies necessary to meet the requirements of future military and commercial engines are explored through ideal cycle analysis. As is shown, military and commercial engines can both benefit from additional research in the areas of advanced materials, compressor design, and component efficiencies. However, advances in commercial engine design will also require additional research in areas such as advanced nacelle design and fan blade aerodynamics. This analysis indicates that future technology transfer between the military and commercial sectors of the engine industry will be characterized more by the transfer of basic research results than by the direct commercialization of military hardware. The implications of this change upon the development of policies for maintaining the competitiveness of the U.S. jet aircraft engine industry are presented and discussed. Thesis Supervisor: Dr. Theodore A. Postol Professor of Science, Technology, and National Security ACKNOWLEDGEMENTS I would like to express my sincere thanks to all those people without whom I could never have completed this thesis. I am particularly indebted to Professor Theodore A. Postol for his continued support throughout the last two years- despite my frequently changing interests and thesis topics. I would also like to thank Dr. George Lewis for his assistance in developing this research topic and for his diligence and patience in reading early drafts of this report. I could never have met my deadline without his help. And, of course, thanks to all my friends in the Technology & Policy Program who made my experience here so enjoyable. Above all though, my sincerest and most heartfelt thanks go to my wife Elizabeth for her constant love and support during the past two years and especially over the past few months when I needed it most. CONTENTS I. INTRODUCTION 7 A. Military-Commercial Relationships 7 B. A Changing Environment in the Aerospace Industry 10 1. Diverging Military and Commercial Requirements 10 2. Declining Military Budget 13 3. Changes in the Basis of Competition 14 C. Objective of this Thesis 16 D. Structure of Thesis 18 II1.AIRCRAFT JET ENGINES: A TUTORIAL 21 A. Background 22 B. Ideal Cycle Analysis 25 1. Stagnation Temperature and Pressure 25 2. Temperature and Pressure Ratios 27 3. Assumptions of Ideal Cycle Analysis 27 C. Turbojet Engine Analysis 28 1. Turbojet Notation 28 2. General Expression for Thrust 29 3. Turbine-Compressor Power Balance for the Turbojet 34 4. Specific Fuel Consumption 36 5. Typical Turbojet Performance 37 D. Turbofan Engine Analysis 42 1. Turbofan Notation 42 2. Turbofan Power Balance 43 3. Turbofan Optimization 44 4. Turbofan Energy Balance 46 5. Typical Turbofan Performance 47 E. Afterburning 49 1. Afterburning Turbojet 51 2. Afterburning Turbofan 52 | III. THE MILITARY'S ROLE IN DEVELOPING EARLY COMMERCIAL 57 GAS TURBINE ENGINES A. Commercial Jet Engines With Military Antecedents 58 1. Pratt & Whitney JT3: The First Commercial Airliner Jet Engine 58 2. Pratt & Whitney JT8 61 3. General Electric CF6: GE's First Commercial High-Bypass Turbofan 61 4. Pratt & Whitney JT9: The First Commercial High-Bypass Turbofan 65 5. CFM International CFM-56 67 B. The Development of the Gas Turbine Engine: An Historical Review 68 1. The First Gas Turbine Engine 69 2. Improved Performance with Axial Flow Engines 71 3. Turbofan Engines 74 4. High-Bypass Turbofan Engines 75 5. Subsequent Developments 77 C. Conclusions 79 1. Apparent Barricades to Technology Transfer 79 2. Reasons for the Successful Technology Transfer 81 3. The Commercial Benefit From Technology Transfer 82 IV. FUTURE AIRCRAFT AND ENGINE REQUIREMENTS 87 A. Basic Aerodynamics 88 1. Forces Acting Upon an Aircraft 88 2. Lift 90 3. Drag 93 4. Lift-to-Drag Ratios 97 5. Changes in Lift and Drag 97 B. Commercial Requirements 98 C. Military Interests 114 1. Military Transports 116 2. Military Bombers 118 3. Fighter/Attack Aircraft 126 D. Summary 138 1 V. PROSPECTS FOR FUTURE COMMERCIALIZATION AND 140 TECHNOLOGY TRANSFER A. Research Directions for Military Engines 141 1. Turbine Inlet Temperature 145 2. Cooling Requirements 152 3. Compressor Design 155 4. Turbine and Compressor Efficiencies 165 5. Bypass Ratio 168 B. Research Directions for Commercial Engines 172 1. Bypass Ratio 172 2. Turbine Inlet Temperature 177 3. Compressor Pressure Ratio 179 4. Advanced Nacelle Design 182 5. Unducted Fan Engines (Propfans) 184 C. Future Commercialization and Technology Transfer 186 1. Direct Commercialization of Military Engines 186 2. Commercialization of Military Engine Cores 188 3. Transfer of Basic Technologies 190 VI. POLICY IMPLICATIONS 193 A. Lessons Learned 194 1. The Significance of Military R&D 194 2. The Changing Relationship 196 B. Policy Implications 198 1. Directions for Military and Commercial Jet Engine Research 199 2. Improving Technology Transfer Mechanisms 201 3. Funding for Subsonic Propulsion Research 203 4. NASA's Role in Engine Validation 204 5. Industrial Collaboration 206 6. Market Strategies 206 7. Increased Globalization of Commercial Engine R&D 208 C. A Final Word 210 References 212 CHAPTER I INTRODUCTION Over the past several decades, the U.S. aircraft industry has maintained a highly competitive status in both the domestic and international markets for military and commercial aircraft. In constant dollars, domestic sales of U.S. aircraft, engines, and parts have increased over fifty percent since 1975, and despite the growing trade deficit for U.S. general merchandise, the trade balance for the American aerospace industry has continued to grow, from approximately $1.5 billion in 1964 to over $22 billion in 1989 (AIAA, 1991, p. 121). The reasons for such success are many and include economic, political, technological, and personal factors. In addition, it is also clear that the role of the U.S. government- -and the U.S. military in particular-in creating and supporting the aircraft industry cannot be overlooked. A. Military-Commercial Relationships: The large military buildup during the Second World War created a vast infrastructure in the U.S. and abroad for the design, fabrication, and production of military aircraft. U.S. manufacturers were able to take advantage of the infrastructure the government had helped construct and developed it into successful military and commercial aircraft industries (NAS/NRC, 1985, pp. 26- 27). The European nations that until then had lead the U.S. in aviation, however, were unable to properly mobilize their manufacturing bases after the war. Much of Germany's industrial infrastructure was destroyed by the war; what remained was prohibited from being used for the production of aircraft for more than a decade after the war. Great Britain's aircraft industry remained fragmented among a number of different manufacturers who failed to consolidate into a unified industry with the capacity and financing to launch a major research and development effort. France's aircraft industry focused solely upon national air transportation and hence had little motivation to develop long-range aircraft (MIT, 1989, p. 21). The U.S. was well-situated to take advantage of its aircraft industry after the war. Government investments had developed a strong industrial base from which the industry could grow, and the military continued to invest