Accession Number : AD0728630

Title :   Flow Fluctuation Measurements at Mach Number 4 in the Test Section of the 12-Inch Supersonic Tunnel (D).

Descriptive Note : Final rept. 25 Jun-1 Aug 69,

Corporate Author : ARNOLD ENGINEERING DEVELOPMENT CENTER ARNOLD AIR FORCE STATION TENN

Personal Author(s) : Donaldson,J. C. ; Wallace,J. P.

Report Date : AUG 1971

Pagination or Media Count : 69

Abstract : Hot-wire anemometry measurements were made in the 12-in. supersonic tunnel of the von Karman gas dynamics facility to determine the level of flow fluctuations in the free stream. Supplementary acoustic measurements were made using a microphone mounted flush with the top surface of a flat plate. Data were obtained at Mach number 4. Reynolds number, based on the wire diameter (d = 0.0001 in.), ranged from 5.0 to 24.0. The hot-wire anemometry results presented are based on the mode concept of Kovasznay and the techniques of Morkovin for hot-wire data reduction. The free-stream results, which are similar to those published by Dr. John Laufer, can be explained by the assymption of a sound source traveling in the tunnel wall boundary layer at a supersonic velocity relative to the free stream. (Author)

Descriptors :   (*SUPERSONIC WIND TUNNELS, *FLOW FIELDS), PERIODIC VARIATIONS, ANALYSIS OF VARIANCE, ANEMOMETERS, PROBES, ACOUSTIC PROPERTIES, MICROPHONES, MATHEMATICAL ANALYSIS, FLAT PLATE MODELS, MODEL TESTS

Subject Categories : Test Facilities, Equipment and Methods

Distribution Statement : APPROVED FOR PUBLIC RELEASE