Air Force Institute of Technology AFIT Scholar Theses and Dissertations Student Graduate Works 3-11-2011 Optimized Dual Expander Aerospike Rocket Joshua N. Hall Follow this and additional works at: https://scholar.afit.edu/etd Part of the Aerospace Engineering Commons Recommended Citation Hall, Joshua N., "Optimized Dual Expander Aerospike Rocket" (2011). Theses and Dissertations. 1326. https://scholar.afit.edu/etd/1326 This Thesis is brought to you for free and open access by the Student Graduate Works at AFIT Scholar. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of AFIT Scholar. For more information, please contact [email protected]. OPTIMIZED DUAL EXPANDER AEROSPIKE ROCKET THESIS Joshua N. Hall, Captain, USAF AFIT/GAE/ENY/11-M10 DEPARTMENT OF THE AIR FORCE AIR UNIVERSITY AIR FORCE INSTITUTE OF TECHNOLOGY Wright-Patterson Air Force Base, Ohio APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED The views expressed in this thesis are those of the author and do not reflect the official policy or position of the United States Air Force, Department of Defense, or the United States Government. This material is declared a work of the U.S. Government and is not subject to copyright protection in the United States. AFIT/GAE/ENY/11-M10 OPTIMIZED DUAL EXPANDER AEROSPIKE ROCKET THESIS Presented to the Faculty Department of Aeronautics and Astronautics Graduate School of Engineering and Management Air Force Institute of Technology Air University Air Education and Training Command In Partial Fulfillment of the Requirements for the Degree of Master of Science in Aeronautical Engineering Joshua N. Hall, B.S. Captain, USAF March 2011 APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED. Abstract Research at the Air Force Institute of Technology (AFIT) focused on designing a cryogenic dual-expander aerospike nozzle (DEAN) upper stage rocket engine to produce 50,000 pounds-force (222.4 kilo-Newtons) vacuum thrust, 464 seconds of vacuum specific impulse and a thrust-to-weight ratio of 106.5. The use of dual expander cycles improves engine reliability, maximizes efficiency, and eliminates some catastrophic failure modes. An upper stage engine with an aerospike nozzle is shorter and lighter than an equivalent performing conventional bell nozzle upper stage engine. Previous research focused on first developing a feasible closed DEAN design model and secondly expanding the model to support parametric trade and optimization studies. The current research effort used previous research as a foundation to create a reliable system level modeling tool to estimate performance, engine weight, and geometry for the DEAN concept. The model incorporated the Numerical Propulsion System Simulation (NPSSTM) software by NASA, Two-Dimensional Kinetics ’04 (TDK’04TM) by Software and Engineering Associates, Inc, and ModelCenterTM by Phoenix Integration. Research obtained a new DEAN design point meeting physical and reusability design constraints from model trade and optimization studies. The new design has a vacuum thrust and a thrust-to-weight ratio of 50,161 lbf (223.1 kN) and 142.2, respectively. Furthermore, the new design has a vacuum specific impulse of 430.6 seconds, failing to meet the vacuum specific impulse design goal by 33.4 seconds or 7.3%. The model used common metals, alloys, and ceramics to improve near-term manufacturability of the DEAN. Current research laid a pathway for further research to find the optimum DEAN design point meeting all the design goals including vacuum specific impulse. iv Acknowledgements First, I would like to thank my Savior, Jesus Christ, for giving me the ability and wisdom to finish this research. Many thanks to LtCol Hartsfield, my thesis advisor, who provided an open ear to toss ideas, let me borrow his textbooks, and provided guidance and support throughout the entire research effort. My sincere thanks to LtCol Branam; he provided me with the thesis idea and provided guidance when I could not figure certain things out. Without his involvement, this research would have never unfolded, especially with his historical background with previous DEAN related research. My sincere thanks also to J. Simmons who was instrumental in the research effort. He graciously provided countless hours assisting me with coding and ModelCenter questions and helping me organize my many thoughts. Thanks to LtCol Huffman for being on my thesis committee and for providing me with a method of characteristics code. The code was instrumental in understanding radial engine geometry defines the design altitude of an aerospike nozzle. Many thanks to Dr. Cohn from the Air Force Research Laboratory at Edwards, AFB for being a part of the research effort and for being on my committee. Thanks also to Doug Coats of Software and Engineering Associates, Inc., for providing his time to answer questions regarding TDK’04 and aerospike nozzle design, and for information regarding the Angelino approximation method, which proved to be a vital component of the research. Lastly, to my wife, family and friends, thank you for your love, continued support and sacrifice throughout the entire project. v Table of Contents Page Abstract .............................................................................................................................. iv Acknowledgements ............................................................................................................. v Table of Contents ............................................................................................................... vi List of Figures .................................................................................................................... ix List of Tables .................................................................................................................... xii List of Symbols ................................................................................................................ xiv List of Abbreviations ..................................................................................................... xviii I. Introduction ...................................................................................................................... 1 I.1 DEAN Model Background and Basic Concept ...................................................... 3 I.2 Research Objectives ................................................................................................ 5 II. Theory and Previous Research ....................................................................................... 7 II.1 Orbit Transfer Engines and Previous Aerospike Engines ....................................... 7 II.1.a. Orbit Transfer Engines ..................................................................................... 7 II.1.b. Previous Aerospike Engines ............................................................................. 9 II.2 Mission Requirements .......................................................................................... 11 II.3 Rocket Engine Theory .......................................................................................... 16 II.3.a. Rocket Engine Design Process ....................................................................... 16 II.3.b. Rocket Engine Cycles .................................................................................... 17 II.3.c. Combustion Chamber Theory ........................................................................ 20 II.3.d. Rocket Nozzle and Rocket Engine Performance Theory ............................... 26 II.3.e. Cooling Jacket Theory .................................................................................... 38 II.3.f. Turbopump (Turbine and Pump) Theory ........................................................ 49 II.3.g. Basic Injector and Plumbing Theory .............................................................. 55 II.3.h. Material Choice .............................................................................................. 58 II.4 Past DEAN Research Efforts ................................................................................ 59 III. Methodology ............................................................................................................... 66 III.1 ModelCenter Overview ......................................................................................... 66 III.2 NPSS ..................................................................................................................... 68 III.2.a. NPSS Overview ............................................................................................ 68 III.2.b. NPSS Elements ............................................................................................. 70 III.2.c. DEAN NPSS Model ...................................................................................... 74 III.3 TDK and Aerospike Nozzle Design Altitude ....................................................... 76 vi Page III.3.a. Method of Characteristics Overview............................................................. 76 III.3.b. TDK Overview .............................................................................................. 78 III.3.c. TDK with CEA and Angelino Nozzle Geometry Approximation ................ 80 III.3.d. TDK Model with Boundary Layer Approximation ...................................... 83 III.3.e. Correction to TDK Outputs ........................................................................... 84