Fundamental Studies of the Structure of Hypersonic Attached and Separated Boundary Layers Over Smooth, Rough and Transpiration-Cooled Surfaces.

摘要

A program of fundamental experimental research and analysis has been conducted to examine two key areas associated with the design of hypersonic vehicles for re-entry and sustained hypervelocity flight. In the first, and major segment of the program, detailed measurements were obtained to examine the thermo-fluid dynamics of transpiration-cooling and the separate and combined effects of surface roughness and blowing on the fluid mechanics of transpiration and ablative thermal protection systems. In the second segment of the program, we embarked in a detailed experimental examination of turbulent compressibility effects in regions of attached and separated flows. The first phase of this program was devoted to studies associated with developing the models and instrumentation to obtain highly resolved high frequency measurements in fully turbulent boundary layer at Mach 11, 13, and 15. While in the second phase of this program, segments were concentrated on the development of the direct measurement of density fluctuations using high pressure electron beam techniques. During this contract we also took the opportunity to analyze and publish important measurements made in an earlier program demonstrating compressibility effects in hypersonic turbulent wakes.