Viscous interaction phenomena in hypersonic wedge flow

Abstract

The present paper deals with an experimental investigation carried out to study some aspects of shock/boundarylayer interaction in nominally two-dimensional hypersonic wedge flow, i.e., over flat plate/ramp configurations. These flow conditions are two dimensional only geometrically because some spanwise periodic variations of the heat flux over the ramp in the reattaching flow region are observed. The measurements, basically made by means of a computerized infrared (IR) imaging system, have been performed in a blowdown wind tunnel at Mach number equal to 7.14 and unit Reynolds number ranging from 7.6 X 10 6 to 24 x 10 6 /m. The influence of the leading-edge shape (bluntness and geometry), flat plate length, and ramp angle on the separation region, average heat transfer at reattachment, and wavelength of the heat transfer variations has been analyzed. IR results are compared to other experimental data as well as to semiempirical correlations for the heat flux peak.

Infrared thermography: An optical method in heat transfer and fluid flow visualisation

“…An alternative approach [23], that works much better in these cases, is based on the assumption that the direct problem yields a certain heat-flux time variation law, where some free parameters are present. Then such parameters are found so that the computed temperatures best agree with the experimentally measured temperatures.…”

Heat flux sensors and infrared thermography

“…To bypass this problem, another way is based on the assumption that the flow yields a certain heat flux time variation law with some free parameters and such parameters are found so that computed temperatures best agree with the experimentally measured ones (de Luca et al, 1995). E.g., the best fit may be determined by means of the ordinary least squares criterion.…”

An overview on hypersonic flow research with infrared thermography

“…For two typical runs, in Fig. 12 the heat flux along the symmetry axis is presented in non-dimensional form by means of the Stanton number based on the adiabatic wall temperature computed by means of the recovery factor for laminar boundary layer flow [10].…”