----------------- FILE NUMBER 910----------------- 1. FLOW TITLE: CASE 8501; "COMPRESSIBILITY EFFECTS ON FREE SHEAR LAYERS" 2. REVISION DATE: NOVEMBER 15, 1980 3. EVALUATOR: BRADSHAW, P., IMPERIAL COLLEGE OF TECHNOLOGY, LONDON, ENGLAND 4. EXPERIMENT LOCATION AND DATE: VARIOUS 5. ABSTRACT: TEST CASE CONSISTS OF DATA OF SPREADING RATE WITH MACH NUMBER. OTHER THAN THE DATA FOR MACH 19 TAKEN FROM REF. 2, NEW DATA ARE NOT STRONG EVIDENCE FOR MODIFYING THE DATA FROM REF. 1 . SINCE THE OBJECT IS TO PREDICT THE ASYMPTOTIC SPREADING RATE AFTER THE EFFECT OF INITIAL CONDITION HAS DISAPPEARED, THE INITIAL PROFILES SHOULD BE CHOSEN BY THE COMPUTER AS THE BEST GUESS AT THE ASYMPTOTIC PREDICTIONS OF HIS METHOD. ROUGHLY, THE VELOCITY PROFILE IS AN ERROR FUNCTION WITH A STANDARD DEVIATION OF 1.3/(DELTA/X), AND IS PROPORTIONAL TO EXP(-Y**2), THE CONSTANT OF PROPORTIONALITY BEING ABOUT 0.01*UE**2 WHEN DELTA/X = 0.115. AT HIGH MACH NUMBER, DENSITY VARIATIONS HAVE AN ILL DOCUMENTED EFFECT ON THE SHEAR STRESS PROFILE. NOTE THAT THE ORIGIN OF THE ERROR FUNCTION PROFILE IS AT THE POINT AT WHICH U/UE = 0.5, WHICH IS NOT THE LINE ETA = 0 . AT LOW SPEEDS, U/UE = 0.5 ON ETA = Y/X = 0.04 APPROXIMATELY. 6. REFERENCES: 1. BIRCH, S. F., EGGERS, W. J., "FREE TURBULENT SHEAR FLOWS" NASA SP-321, VOL.1, 1972 2. HARVEY, W. D., HUNTER JR., W. W., "EXPERIMENTAL STUDY OF A FREE TURBULENT SHEAR FLOW AT MACH 19 WITH ELECTRON BEAM AND CONVENTIONAL PROBES" NASA TN D-7981, 1975 7. INSTRUMENTATION: MEASUREMENTS WERE MADE USING VARIOUS TECHNIQUES INCLUDING ELECTRON BEAM, CONVENTIONAL PITOT TUBE AND TOTAL TEMPERATURE PROBE TECHNIQUES. 8. EXPERIMENTAL PARAMETERS: MACH NUMBER (XM) : ....................... 0 < M < 5 AND M = 19 SPREADING RATE PARAMETER AT XM = 0 (SIGMA 0) : ..... 11.1 VELOCITY RATIO U2/U1 : .............................. 0.0 9. MEASURED VARIABLES: MEASURED VARIABLES INCLUDE MACH NUMBER, VELOCITY, TOTAL PRESSURE AND TOTAL TEMPERATURE. THE DATA ARE REPORTED AS A TABLE OF VALUES OF (SIGMA / SIGMA 0) CONVERTED TO DELTA/X CORRESPONDING TO VALUES OF THE MACH NUMBER. SIGMA IS THE SPREADING RATE PARAMETER (INVERSELY PROPORTIONAL TO THICKNESS) AND DELTA DEFINES THE THICKNESS FOR U/UE 0.316 TO 0.949 10. UNCERTAINTY: BIRCH, S. F., ESTIMATES THE ERROR BAND AS + OR - 5 PERCENT AT LOW SPEEDS INCREASING TO + OR - 10 PERCENT AT XM = 5. ERROR AT XM = 19 IS INDICATED BY THE TWO VALUES. 11. TAPE ORGANIZATION: THE TAPE IS A 2400 FOOT, 9 TRACK, ODD PARITY, PHASE ENCODED UNLABELLED TAPE WRITTEN AT A DENSITY OF 1600 BITS PER INCH ACCORDING TO EBCDIC CODE. THE RECORD FORMAT IS FIXED AND BLOCKED; RECORD LENGTH = 80 BYTES; BLOCKSIZE = 8000 BYTES NORMALIZED DATA ARE CREATED FROM MEASURED DATA AS FOLLOWS: XNORM = (X - XMIN)/(XMAX - XMIN) NORMALIZED VALUES ARE INTEGERIZED BY MULTIPLYING BY 10000 AND ROUNDING UP OR DOWN TO THE NEAREST INTEGER. IXNORM = XNORM * 10000. THUS EACH NORMALIZED DATUM IS WRITTEN ONTO TAPE AS AN INTEGER VALUE BETWEEN 0 AND 10000. ALL NULL DATA ARE WRITTEN AS 20000 THE EQUATION DESCRIBING THE RELATION BETWEEN ACTUAL DATA AND THE NORMALIZED DATA ON TAPE ARE X = XMIN + (((XMAX - XMIN) * IXNORM)/10000.) WHERE X, XMAX AND XMIN ARE REAL AND IXNORM IS INTEGER. FILE# NREC CONTAINS FORMAT COMMENTS 1 - TEXT FILE - CONTAINS ITEMS 1 TO 11 OF THIS WRITE-UP 2 15 XM, (SIGMA / SIGMA 0), 3E13.6 RECORD 1- MAXIMUM DELTA / X VALUES XM, (SIGMA / SIGMA 0), 3E13.6 RECORD 2- MINIMUM DELTA / X VALUES XM, (SIGMA / SIGMA 0), 3I6 RECORDS 3-15 DELTA / X NORMALIZED VALUES A SAMPLE PROGRAM FOR READING FILE 2 AND PRINTING IT IS SHOWN BELOW. THE JCL SHOWN IS FOR THE STANFORD CIT FACILITY. CHECK WITH YOUR OWN COMPUTER INSTALLATION FOR THE EXACT JCL NEEDED //TAPE JOB BZC$NJ /*SETUP TAPE=1,INPUT=(LIBRARY NUMBER ASSIGNED TO TAPE) // EXEC FORTCG //FORT.SYSIN DD * C TO READ FILE 2 OFF TAPE C PRINT MAXIMAS AND MINIMAS OF ALL THE VARIABLES C PRINT NORMALIZED INTEGERIZED VALUES OF ALL THE VARIABLES. INTEGER MACH(13),SIGMA(13),DELTA(13) READ (23,30) XMCHMX,SIGMMX,DELTMX READ (23,30) XMCHMN,SIGMMN,DELTMN DO 10 I = 1, 13 10 READ (23,40) MACH(I),SIGMA(I),DELTA(I) WRITE (6,50) XMCHMX,SIGMMX,DELTMX WRITE (6,50) XMCHMN,SIGMMN,DELTMN DO 20 I = 1, 13 20 WRITE (6,60) MACH(I),SIGMA(I),DELTA(I) 30 FORMAT(3E13.6) 40 FORMAT(3I6) 50 FORMAT(1X,3E13.6) 60 FORMAT(1X,3I6) STOP END //GO.FT23F001 DD UNIT=T1600,VOL=SER=(TAPE LIBRARY NUMBER), // DISP=(OLD,KEEP),DCB=(RECFM=FB,LRECL=80,BLKSIZE=8000,DEN=3), // LABEL=(2,NL) // -------------- END OF FILE NUMBER 910------------- ----------------- FILE NUMBER 911----------------- 0.190000E 02 0.490000E 01 0.115000E-00 0.000000E 00 0.100000E 01 0.235000E-01 0 0 10000 263 0 10000 526 103 9517 789 1000 6475 1053 2103 4339 1316 3128 3095 1579 4051 2306 1842 4718 1860 2105 5205 1582 2368 5718 1326 2632 6128 1142 10000 6282 1078 10000 10000 0 -------------- END OF FILE NUMBER 911-------------  5718 1326 2632 6128 1142