BibTeX
@MISC{Prabhu_pressuregradient,
author = {Ramadas K. Prabhu},
title = {Pressure Gradient Effects on Hypersonic Cavity Flow Heating},
year = {}
}
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Abstract
The effect of a pressure gradient on the local heating disturbance of rectangular cavities tested at hypersonic freestream conditions has been globally assessed using the two-color phosphor thermography method. These experiments were conducted in the Langley 31-Inch Mach 10 Tunnel and were initiated in support of the Space Shuttle Return-To-Flight Program. Two blunted-nose test surface geometries were developed, including an expansion plate test surface with nearly constant negative pressure gradient and a flat plate surface with nearly zero pressure gradient. The test surface designs and flow characterizations were performed using two-dimensional laminar computational methods, while the experimental boundary layer state conditions were inferred using the measured heating distributions. Three-dimensional computational predictions of the entire model geometry were used as a check on the design process. Both open-flow and closed-flow cavities were tested on each test surface. The cavity design parameters and the test condition matrix were established using the computational predictions. Preliminary conclusions based on an analysis of only the cavity centerline data indicate that the presence of the pressure gradient did not alter the open cavity heating for laminar-entry/laminar-exit flows, but did raise the average floor heating for closed cavities. The results of these risk-reduction studies will be used to formulate a heating assessment of potential damage scenarios occurring during future Space Shuttle flights. I. Nomenclature
Keyphrases
pressure gradient effect hypersonic cavity flow heating pressure gradient experimental boundary layer state condition langley 31-inch mach test condition matrix test surface design design process constant negative pressure gradient cavity design parameter blunted-nose test surface geometry two-color phosphor thermography method laminar-entry laminar-exit flow three-dimensional computational prediction test surface space shuttle return-to-flight program closed cavity cavity centerline data heating distribution risk-reduction study average floor heating two-dimensional laminar computational method preliminary conclusion local heating disturbance entire model geometry flow characterization closed-flow cavity potential damage scenario open cavity expansion plate test surface computational prediction flat plate surface heating assessment hypersonic freestream condition future space shuttle flight rectangular cavity
