General Disclaimer One or more of the Following Statements may affect this Document This document has been reproduced from the best copy furnished by the organizational source. It is being released in the interest of making available as much information as possible. This document may contain data, which exceeds the sheet parameters. It was furnished in this condition by the organizational source and is the best copy available. This document may contain tone-on-tone or color graphs, charts and/or pictures, which have been reproduced in black and white. This document is paginated as submitted by the original source. Portions of this document are not fully legible due to the historical nature of some of the material. However, it is the best reproduction available from the original submission. Produced by the NASA Center for Aerospace Information (CASI) M-TU-75-5 F^ May 1975 • 4::7SPAC1' GEORGE C ^/CNT EN^fR l SYSTEM ANALY S IS OF A P I STON STEAM ENGINE EMPLOYING THE UNIFLOW PRINCIPLE, A STUDY IN k OPTIMIZED PERFORMANCE By Jerry A. Peoples (NASA-TM-X-66918) SYSTEM ANALYSIS OF A N75-24544 PISTON STEAM SNGINE EMPLOYING THE UNIFLOW UPINCIPLE, A ST?IDY IF OPTIMIZED PE&FO..MANCE (NAS,i ) 76 p HC $4.75 CSCL 21G Unclas G3/85 21845 v t^ • v 1 / - Ito ^6 sponsored by: Technology Util ization Office K kTIONAL AERONAUTICS AND SPACE ADMINISTRATION MSFC - Furm 4S4 (Rry October 1967) y TFf'Wki1(-A1 1aFMnPT CTANr1ARr1 TITI P PAGF REPORT 40. 2 GOVERNMENT ACCESSION NO. 3, RECIPIENT'S CATALOG NO. M-TU-15-5 s TITLE ANO SUISTITL[ 5. REPORT DATE blay 1975 System Analysis of a Piston Steam Engine Employing the Uniflow PERFORMING ORGANIZATION CURE Principle, a Study in Optimized Performance 6 7. AUTNORIS) 8 PERFORMING ORGANIZATION REPfwtf R Jerry A. Peoples p PERFORMING ORGANIZATION NAME AND ADDRESS 1D. WORK UNIT NO. George C. Marshall Flight Center 1 ), CONTRACT OR GRANT N0. Marshall Space Flight Center, Alabama 35812 13. TYPE OF REPOP- & PERIOD COVERFO 1 2 SPONSORING AGENCV NAME AND ADDRESS Miscellaneous National Aeronautics and Space Administration t.1 SPONSORING AGENCY CODE W8 ,ington, D.C. 20546 15 SUPPLEMENTARY NOTES Prepared by Program Development, Preliminary Design Office I& ANSTRACT Results are reported which were obtained f rom a math model of a generalized piston steam engine configuration employing the uniflow principal. The model accounted for the effects of clearance volume, compression work, and release volume. In spite of the thousands of possible combinations of particular values for ten basic parameters, a very simple solu,ion is presented which characterizes optimum performance of the steam engine, based on miles per gallon. Development of the math model is presented. Also, the relationship between efficiency and iniles per gallon is developed. Most important, an I approach to steam car analysis and design is presented which has purpose rather than lucky hopefulness. Finally, a practical engine desigii is proposed which correlates to the definition of the type engine used in this study. This engine integrates several system components into the engine structure. All conclusions relate only to the classical Rankine Cycle. 17. KEY WORDS IS DISTRIBUTION STATEMENT Unclassified — Unlimited al i,1 a 19 SECURITY CLASSIF, (a/ this repot") 20 SECURITY CLASSIF, (of this Pegs) 21 NO. OF PAGES 22. PRICE Unclassifiec' t1 ncla ssif ied 84 NTIS MSFC • Form 3102 (Rev December 1bT1) ror sale by NationAl Technical In(nrmatinn Service, Springfield, Virginia 22151 TABLE OF CONTENTS Page SUMMARY ......................................... 1 I. INTRODUCTION ................................ 1 II. BACKGROUND INFORMATION ....................... 2 III. ENGINE DEFINITION ............................. 4 IV. FUNDAMENTAL BEHAVIOR OF THE GUFFIN ENGINE ...... 7 V. DETAILED DESCRIPTION OF THE GUFFIN ENGINE ANALYSIS .................................... 14 VI. PHYSICS OF THE GUFFIN ENGINE ................... 22 VII. SYNTHESIS OF EFFICIENCY ................ ....... 26 VIII. TINKER ENGINE CYCLE ........................ 38 D{. CONCLUSIONS ................................. 44 APPENDIX A: MILES PER GALLON RELATIONSHIP FOR THE GUFFIN ENGINE .......................... 45 APPENDIX B: VEHICLE LIMITING SPEED CAPABILITY ......... 57 APPENDIX C: A TABULATION OF TYPICAL DATA ............. 62 APPENDIX D: DEVELOPMENT OF THE TIIOMPSON EQUALITY .... 65 REFERENCES ...................................... 68 iii J^ N -A LIST OF ILLUSTRATIONS Figure Title Page ^ PSI I 1. P_V diagram of the Guilin Engine ................... 5 2. Sensitivity of the Guilin Engine to Supply pressure........ 10 3. The optimizing nature of cutoff .................... 1.1 4. Sensitivity of optimum performance to clearance VO1L1111C ... 12 5. Sensitivity of performance to pressure for iO1V tCllll)Cl'11tt11'C .. .. .. .. .. .. .. .. .... .. ..... 15 ti. Sensitivity Of pLefol'111:111CL to pressure for high LCl11I)CratUre . .. .. .. .... .. .. .. .. ...... 10 a 7. A s1mcial Lase Of performance at'/.LrO Cutoff .. .. .. ... 17 S. V lViat1011 Of ;1110 OI)ti111L1111 CLILOrr rot' V lViOLIS co lllbina Lions noted in Tablo 1 .............................. 18 9. Variation Of ill' OfAilluuu Cutoff for various combinations noted in Table 2................ I ......... 6 ..... 19 10. Relationship between performance and vehicle speed ...... 22 11. All illustration Of 11OW the GLlffio Suppic Nu mber drives the pOSiti011 Of Optilllllill cuLCrr . ......... 27 12. Percent increase in Carnot efficiency With percent increase in Supply temperature above 700° F .................. 28 13. Percent increase it) mpg of the Guffin engine above that which is achieved uC t15c) cpt.intunt cutoff aL 700°F and 800 Asia .. 20 ll. Effect of expaws.on r ltio oil cycle efficiency for various Stcalll ellesL LCmperatures and I)rCSSL11'C S . 31 15. A buid atLempt to relate theoretical Lhcrnnal efficiency of t11C Rankine cycle to the mpg capability of the Guff'in stcnnn L'I1g111C 1111 32 iv LIST OF ILLUSTRATIONS Figure '1'itic Pale 1. P-V diagram of the Guffin Engine 2. Sensiti% ity Of the Gidlin Engine to suppl y Oi'CSSUre . 10 .1. The Optimizing nature Of cutoff ..... .. ........ .. ... 1.1 4. Sensitivity of optimum performance to clearance volcunc ... 12 .5. Sensitivily of performance to pressure for low temperature ...... .. .. .. ... .... ...... .. .. 15 G. Sensitivity of performance to pressure for high temperature .... .. .. .. .. ...... ............ 1G 7. A special case of performance at zero cutoff .... ...... 17 t3. Variation of the optimum cutoff for various conilWtions noted in 1:a h! I . ........ .... .. ... lti 9. Variation Of th , Optirivaln cutoff for various conilMmLions notcq I in '!'able : .. .... .. .. .. 19 lo. Relationship between perfurnt;ance and vehicle speed . .. 22 IL An illustration of how the Guffin Sulq,le Nundwr dries thi position of optimum cutoff .. .. ..... ..... .27 12. Percent increase III Carnot efficiency with lwreent increase in sulgdy tenMwr:aturc alwve 700 l' . 28 13. Percent increase in mph of the Guffin engine above that which is achieved A tQ uW;muni cutoff at 7W It and 610 1whi .... 29 14. Met of expa ► shni ratio on Itanl:ine cycle efficiency for various stc;lni chest tenillerall1res and pressures . ... ... :; I 15. :; hold atteulpt to relate theoretical thermal cfficieney Of the Rankine eyrie to the nipg capability of the Guffin titoant cngine .. ........ .. ..... .. .. .... .. ... lv r t LIST OF ILLUSTRATIONS (Concluded) Figure Title Page 10. Relationship between laboratory measured efficiency and mpg of the Guffin Engine ................ I ........ 37 17. P-V diagram for Tinker engine .................... 38 18. Tinker engine cross section at TDC ................. 39 19. Tinker engine cross section at BDC ................. 40 20. A chart of entropy versus temperature for the Tinker engine ..................................... 42 A-1. P-V diagram for the Guffin engine ............... .. 45 A-2. Mixing of the characteiAcs mass with the admission mass ... 47 A-3. Effects of the compressible factor .................. 51 A-4. Guffin engine pressure — volume diagram ............. 54 v t------- L ST OF ILLUSTRATIONS (Concluded) • Figure Title Pa;;e 16. Relationship between laboratory measured efficiency and ' mpg of the Guffin Engine .......... .. .... .. .. 37 17. P-V diagram for Tinker engine . 38 18. Tinker engine cross s ection at TDC .. .... .. .... .... 39 19. Tinker engine cross section at BDC .. ......... 40 20. A chart of entropy versus temperature for the Tinker engine ...... 42 A-1. P-V diagram for the Guffin engine ... .... .. .. 45 A-2. Mixing of the characte . ics mass with the admission mass.. 47 A-3. Effects of the compressible factor ... .. .. .. .. .... 51 A-4. Guffin engine pressure — volume diagram .... .. .. ..... 54 v `^ r f ^ LIST OF TABLES Table Title Page 1. Combinations Used for Figure 8 .................... 20 2. Combinations Used for Figure 0 .................... 20 3. Variation of mpg With Different Combinations of Polytropic Exponents for Expansion and Compression Processes .................................. 21 4. Percent Reduction in the Guffin Dour Number, D G , .aid it AIass Ratio Cutoff as the ExhaUBt Pressure is Changed from 5 to 15 Asia .............................. 25 5. Engine Efficiency Data for Standard Conditions .......... 34 0. Engine Effi,. lency Data for Standard Conditions .......... 35 7. Engine Efficiency Data for Standard Conditions .......... 36 C-1. Typical Values for Gallia llour Numbers and Mass Ratio Cutoff ..................................... 03 C-2.