Accession Number : AD0453850

Title :   GROWTH OF THE TURBULENT INNER WAKE BEHIND LARGE SPHERES AT SUPERSONIC VELOCITIES,

Descriptive Note : Memorandum rept.

Corporate Author : BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

Personal Author(s) : Braun,Walter F.

Report Date : SEP 1964

Pagination or Media Count : 37

Abstract : Experimental data are presented on the growth of the envelope of the turbulent inner wakes up to 3000 calibers behind 9/16, 3/4 and 2-inch spheres traveling at supersonic velocities. A description of the experimental technique and a discussion of its limitations for obtaining adequate data are given. Data are fitted to the equation r cubed 3 - bx sub e = c and the growth of the far wake is compared with theoretical predictions. Values of C sub D are computed using the coefficient b from this equation in the expression b = 1.85 KC sub D. Since there exists an aperiodic development of the wake envelope and since the small sample size of the data may bias the determination of the growth rate, the data from all available rounds were averaged to obtain values of C sub D. (Author)

Descriptors :   (*SPHERES, WAKE), TURBULENCE, MEASUREMENT, SUPERSONIC CHARACTERISTICS, EXPERIMENTAL DATA, INSTRUMENTATION, MATHEMATICAL PREDICTION, SUPERSONIC TEST VEHICLES, SPARK SHADOWGRAPH PHOTOGRAPHY, SCHLIEREN PHOTOGRAPHY

Distribution Statement : APPROVED FOR PUBLIC RELEASE