Accession Number : AD0266702

Title :   CALCULATION OF FLOW FIELDS FROM BOW-WAVE PROFILES FOR THE DOWNSTREAM REGION OF BLUNT-NOSED CIRCULAR CYLINDERS IN AXIAL HYPERSONIC FLIGHT

Corporate Author : NATIONAL AERONAUTICS AND SPACE ADMINISTRATION WASHINGTON D C

Personal Author(s) : SEIFF,ALVIN ; WHITING,ELLIS E.

Report Date : NOV 1961

Pagination or Media Count : 1

Abstract : A method by which known bow-wave profiles may be analyzed to give the flow fields around bluntnosed cylinders in axial hypersonic flow is presented. The assumption is made that the pressure distribution curve in a transverse plane is similar to that given by blast-wave theory. Numerical analysis based on the one-dimensional energy and continuity equations then leads to distributions of all the flow variables in the cross section, for either a perfect or a real gas. The entire flow field need not be solved. Attention can be confined to any desired station. The critical question is the validity of the assumption. It is tested for a hemisphere cylinder in flight at 20,000 ft/sec. The flow is analyzed for three stations along the cylindrical afterbody, and compared closely with the results of an exact (inviscid) solution. The assumed form of the pressure distribution occurs at stations as close as 1.2 diameters to the body nose. However, it is suggested that the assumption may not apply this far forward in general, particularly when bodies of nonsmooth contour are considered. (Author)

Descriptors :   *BLUNT BODIES, AERODYNAMIC CHARACTERISTICS, BODIES OF REVOLUTION, CYLINDRICAL BODIES, GAS FLOW, HYPERSONIC FLOW, MATHEMATICAL ANALYSIS, SHOCK WAVES, THEORY, WAKE

Distribution Statement : APPROVED FOR PUBLIC RELEASE