View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by University of Tennessee, Knoxville: Trace University of Tennessee, Knoxville Trace: Tennessee Research and Creative Exchange Masters Theses Graduate School 5-2012 A Method for Performance Analysis of a Ramjet Engine in a Free-jet Test Facility and Analysis of Performance Uncertainty Contributors Kevin Raymond Holst [email protected] Recommended Citation Holst, Kevin Raymond, "A Method for Performance Analysis of a Ramjet Engine in a Free-jet Test Facility and Analysis of Performance Uncertainty Contributors. " Master's Thesis, University of Tennessee, 2012. https://trace.tennessee.edu/utk_gradthes/1163 This Thesis is brought to you for free and open access by the Graduate School at Trace: Tennessee Research and Creative Exchange. It has been accepted for inclusion in Masters Theses by an authorized administrator of Trace: Tennessee Research and Creative Exchange. For more information, please contact [email protected]. To the Graduate Council: I am submitting herewith a thesis written by Kevin Raymond Holst entitled "A Method for Performance Analysis of a Ramjet Engine in a Free-jet Test Facility and Analysis of Performance Uncertainty Contributors." I have examined the final electronic copy of this thesis for form and content and recommend that it be accepted in partial fulfillment of the requirements for the degree of Master of Science, with a major in Aerospace Engineering. Basil N. Antar, Major Professor We have read this thesis and recommend its acceptance: Robert W. McAmis, Roy J. Schulz Accepted for the Council: Dixie L. Thompson Vice Provost and Dean of the Graduate School (Original signatures are on file with official student records.) A Method for Performance Analysis of a Ramjet Engine in a Free-jet Test Facility and Analysis of Performance Uncertainty Contributors A Thesis Presented for the Master of Science Degree The University of Tennessee, Knoxville Kevin Raymond Holst May 2012 Approved for Public Release; Distribution is Unlimited. Copyright © 2012 by Kevin Raymond Holst All rights reserved. ii For Brian iii ACKNOWLEDGEMENTS I would like to express my heartfelt gratitude to the individuals that offered their knowledge and support during the preparation of this thesis. Dr. Rob McAmis guided me during my coursework at UTSI and helped push me to complete this thesis. Many hours were spent in his office in search of a thesis topic and a direction from which to approach it. The time he has devoted to helping me on this thesis, on my coursework, and through my career at AEDC is a testament to his high character and integrity. Dr. Doug Garrard at AEDC provided a task for me that was able to be spun into this thesis and offered his knowledge and expertise on the topic when needed. Mark Cross at AEDC made available his wealth of ground testing and uncertainty knowledge to help formulate this thesis. Dr. Roy Schulz offered a careful critique of this work which helped to clarify the topic and to give it additional technical depth. Dr. Basil Antar also provided a review of this proposal and graciously served as my thesis committee chair. Finally, I would like to acknowledge the patience and support of my wife, Kimberly. I will be forever grateful for her understanding of my desire to continue classes and complete this thesis, and her ability to help me retain my focus and positive outlook on the task. iv ABSTRACT Ramjet and scramjet engines are being developed to provide a more fuel efficient means of propulsion at high Mach numbers. Part of the development of these engines involves test and evaluation of an engine in ground facilities as well as in flight. Ground facilities, like Arnold Engineering Development Complex (AEDC) and those at engine manufacturers like General Electric (GE) and Pratt & Whitney (PW), have decades of experience testing traditional turbine engines and much less experience testing full scale ramjet engines. Testing a supersonic engine in a free-jet mode presents a host of challenges not experienced during traditional direct connect turbine engine tests. Characterizing the performance of an engine in a free-jet test facility is a difficult task due in part to the difficulty in determining how much air the engine is ingesting and the spillage, friction and base drag of the engine installation. As more exotic propulsion systems like DARPA’s Falcon Combined Cycle Engine Test (FaCET) article or NASA’s X-43 are developed, there is a greater need for effective ground tests to determine engine performance and operability prior to flight testing. This thesis proposes a method for calculating three key performance parameters (airflow, fuel flow, and thrust) and investigates the uncertainty influences for these calculations. A data reduction method was developed for this thesis to calculate the engine airflow, net thrust, and specific impulse (ISP) in a ground test of a generic ramjet engine in a free-jet test facility. It considered typical measurements for an engine test (pressures, temperatures, fuel flow, scale force, and engine and cowl geometry). Once the code was developed, an uncertainty analysis of the calculations was conducted, starting with a simplified analytical assessment. A common industry accepted uncertainty approach was then used in conjunction with the data reduction code to determine the sensitivity or influence coefficients of the independent measurements on the dependent parameters by the dithering method. These influence coefficients were v used to ascertain where measurement improvements could be made to affect the greatest reduction in uncertainty of the predicted engine performance. vi TABLE OF CONTENTS CHAPTER I Introduction and Problem Statement ............................................................ 1 Ground Test Facilities ..................................................................................................... 1 Ramjet and Scramjet Background .................................................................................. 2 Free-jet Testing Compared to Direct Connect Testing ................................................... 5 Instrumentation ............................................................................................................... 8 Data Analysis .................................................................................................................. 9 Problem Statement ........................................................................................................ 10 CHAPTER II Literature Review ...................................................................................... 11 Ramjet Performance Analysis ....................................................................................... 11 Uncertainty .................................................................................................................... 11 Measurement Uncertainty ......................................................................................... 11 Calculation Uncertainty ............................................................................................ 15 Standardization of Ramjet Performance Reporting ...................................................... 16 CHAPTER III Approach................................................................................................... 18 Outline........................................................................................................................... 18 Data Reduction.............................................................................................................. 18 Engine Airflow.......................................................................................................... 18 Engine Net Thrust ..................................................................................................... 22 Specific Impulse........................................................................................................ 24 Sample Data .................................................................................................................. 27 Uncertainty Analysis ..................................................................................................... 28 Numerical Uncertainty Analysis ............................................................................... 29 Simplified Analytical Uncertainty Analysis ............................................................. 29 CHAPTER IV Results and Discussion ............................................................................ 33 Performance Analysis ................................................................................................... 33 Uncertainty Analysis ..................................................................................................... 35 Airflow ...................................................................................................................... 35 Net Thrust ................................................................................................................. 39 vii Specific Impulse........................................................................................................ 42 CHAPTER V Conclusions and Recommendations ......................................................... 46 Works Cited ...................................................................................................................... 48 Appendix ..........................................................................................................................