A THERMOACOUSTIC ENGINE REFRIGERATOR SYSTEM FOR SPACE EXPLORATION MISSION by SUDEEP SASTRY Submitted in partial fulfillment of requirements for the degree of Doctor of Philosophy Dissertation advisor: Dr. Jaikrishnan R. Kadambi Department of Mechanical and Aerospace Engineering CASE WESTERN RESERVE UNIVERSITY May 2011 CASE WESTERN RESERVE UNIVERSITY SCHOOL OF GRADUATE STUDIES We hereby approve the thesis/dissertation of ______________________________________________________ candidate for the ________________________________degree *. (signed)_______________________________________________ (chair of the committee) ________________________________________________ ________________________________________________ ________________________________________________ ________________________________________________ ________________________________________________ (date) _______________________ *We also certify that written approval has been obtained for any proprietary material contained therein. सरवित नमतुयं वरदे कामरूिपिण । िवारभं किरयािम िसिभर्वतु मे सदा ॥ कमर्ण्येवािधकारते मा फलेषु कदाचन। मा कमर्फलहेतुभूर्मार् ते सोत्वऽकमर्िण॥ - Bhagavad Gītā To, My parents, and, my brother Table of Contents TABLE OF CONTENTS.............................................................................................. 1 LIST OF TABLES ......................................................................................................... 5 LIST OF FIGURES ....................................................................................................... 6 ACKNOWLEDGEMENTS ........................................................................................... 9 ABSTRACT .................................................................................................................. 11 NOMENCLATURE .................................................................................................... 13 1. INTRODUCTION .................................................................................................. 18 1.1 MOTIVATION ............................................................................................................................ 18 1.2 OBJECTIVES .............................................................................................................................. 27 1.3 OUTLINE ................................................................................................................................... 28 2. LITERATURE REVIEW ........................................................................................ 29 2.1 EARLY HISTORY ....................................................................................................................... 29 2.2 DEVELOPMENT OF THE THERMOACOUSTIC THEORY ......................................................... 32 2.3 THERMOACOUSTIC ENGINES ................................................................................................. 34 2.4 THERMOACOUSTIC REFRIGERATORS .................................................................................... 35 2.5 STANDING WAVE AND TRAVELING WAVE SYSTEMS .......................................................... 36 2.6 THERMOACOUSTIC ENGINE-REFRIGERATOR SYSTEMS ..................................................... 38 3. THERMOACOUSTICS: CONCEPTS AND THEORY ........................................ 40 1 3.1 THERMODYNAMICS ................................................................................................................. 40 3.2 THE THERMOACOUSTIC EFFECT ............................................................................................ 43 3.3 RELEVANT ACOUSTIC CONCEPTS ......................................................................................... 47 3.4 PRINCIPLE OF THERMOACOUSTICS ....................................................................................... 50 3.5 CRITICAL TEMPERATURE GRADIENT ................................................................................... 61 4. DESIGN: PARAMETRIC STUDY AND MODELING ........................................ 63 4.1 METHOD OF ANALYSIS ........................................................................................................... 63 4.2 DESIGN CONSIDERATIONS .................................................................................................... 65 4.3 DESIGN OF THE THERMOACOUSTIC ENGINE-REFRIGERATOR SYSTEM ......................... 66 4.4 LENGTH SCALES ...................................................................................................................... 67 4.6 PARAMETRIC STUDY OF THE SYSTEM .................................................................................... 69 4.7 SELECTION OF GAS ................................................................................................................. 71 4.8 DYNAMIC PRESSURE ................................................................................................................ 74 4.9 AVERAGE PRESSURE................................................................................................................ 75 4.10 FREQUENCY ........................................................................................................................... 78 4.11 OPTIMIZATION OF THE STACK ............................................................................................ 79 4.11.1 Stack Material ................................................................................................................... 80 4.11.2 Stack Location ................................................................................................................... 81 4.11.3 Stack Geometry .................................................................................................................. 82 4.11.4 Stack Spacing .................................................................................................................... 82 4.11.5 Stack Length ..................................................................................................................... 83 4.12 HEAT EXCHANGERS .............................................................................................................. 85 4.13 HEAT ADDITION TEMPERATURE ........................................................................................ 86 4.14 HEAT REJECTION TEMPERATURE ....................................................................................... 88 2 4.15 RESONATOR GEOMETRY ...................................................................................................... 89 5. RESULTS AND DISCUSSION .............................................................................. 91 5.1 DESIGN OF VENUS-HIGH-ALTITUDE SYSTEM ...................................................................... 91 5.2 OVERALL DESIGN ................................................................................................................... 93 5.3 DESIGN OF VENUS-SURFACE SYSTEM ................................................................................... 96 5.4 DESIGN CONSTRAINTS FOR VENUS-SURFACE SYSTEM ....................................................... 96 5.5 OVERALL DESIGN OF THE VENUS SURFACE SYSTEM ........................................................ 96 6. DESIGN OF A PROTOTYPE SYSTEM .............................................................. 104 6.1 CONSIDERATIONS FOR FABRICATION ................................................................................ 104 6.2 COMPONENTS OF THE ENGINE-REFRIGERATOR SYSTEM .............................................. 104 6.2.1 Engine Stack Material ...................................................................................................... 104 6.2.2 Refrigerator Stack Material ............................................................................................... 105 6.2.3 Engine Hot Heat Exchanger ............................................................................................ 105 6.2.4 Middle Heat Exchangers .................................................................................................. 106 6.2.5 Cold Heat Exchanger ....................................................................................................... 107 6.2.6 Resonator Geometry .......................................................................................................... 107 6.3 SUGGESTED MEASUREMENTS ............................................................................................. 110 7. CONCLUSIONS AND RECOMMENDATIONS ................................................ 111 7.1 CONCLUSIONS ....................................................................................................................... 111 7.2 RECOMMENDATIONS FOR FUTURE WORK ......................................................................... 113 APPENDIX A – AMBIENT HEAT EXCHANGER CALCULATIONS................. 115 APPENDIX B - OPTIMIZATION RESULTS OF GAS MIXTURE RATIO .......... 118 3 B.1 OPTIMIZATION USING HELIUM-ARGON GAS MIXTURE AS WORKING FLUID .............. 118 APPENDIX C - DELTAEC FILES .......................................................................... 123 REFERENCES ......................................................................................................... 137 4 List of Tables TABLE 4. 1: DESIGN CONDITIONS FOR THE THERMOACOUSTIC ENGINE-REFRIGERATOR .... 66 TABLE 5.1: PARAMETERS OF THE THERMOACOUSTIC ENGINE REFRIGERATOR SYSTEM .......... 92 TABLE 5. 2: PARAMETERS OF THE THREE UNITS OF THE THERMOACOUSTIC ENGINE REFRIGERATOR