Accession Number : AD0463882


Title :   NEAR-WAKE FLOWFIELD MEASUREMENTS (TASK 2.2 EXPERIMENTAL FLOWFIELDS -- REST PROGRAM)


Descriptive Note : Technical memo.


Corporate Author : AVCO CORP WILMINGTON MA RESEARCH AND ADVANCED DEVELOPMENT DIV


Personal Author(s) : Todisco, A ; Pallone, A


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/463882.pdf


Report Date : 05 May 1965


Pagination or Media Count : 57


Abstract : Measurements of the stagnation temperature field behind a 10-degree half-angle wedge and a 10-degree half-angle cone have been made in the Avco RAD hypersonic shock tunnel at Mach 16 and stagnation temperature of 2400 K, using a constant temperature hot-wire anemometer. The effect of Reynolds number and wall-to-stagnation temperature ratios was investigated. Reynolds numbers of 5.7 x 10,000/ft and 4.8 x 100,000/ft and ratios of wall-to-stagnation temperature of 0.0325, 0.125, and 0.155 were used. Experimental results showing wake centerline stagnation temperatures and some transverse stagnation temperature profiles are presented. For both the cone and wedge, a region of constant temperature exists for a distance of 0.3 to 0.75 base diameters from the model base. This region of constant temperature is then followed by a region of increasing temperature typical of far-wakes. For the models tested, the stagnation temperature in the nearwake was found to decrease with increasing Reynolds number and to approach a limiting value as the ratio of wall-to-stagnation temperature approaches zero. These limiting values are a function of Reynolds number. Schlieren photographs show that the time for wake formation is of the order of 1 millisecond.


Descriptors :   *HYPERSONIC FLOW , *FLUID FLOW , *WAKE , TEST METHODS , WEDGES , STAGNATION POINT , ANEMOMETERS , HYPERSONIC WIND TUNNELS , SCHLIEREN PHOTOGRAPHY , FLUID MECHANICS , SHOCK WAVES , TEMPERATURE , MEASUREMENT , CONICAL BODIES


Subject Categories : Fluid Mechanics


Distribution Statement : APPROVED FOR PUBLIC RELEASE