Simulations of Shock-Wave/Boundary Layer Interaction on Compression Ramps
Abstract
A computational study of shock-wave/boundary layer interactions on compres- sion ramps was conducted using implicit large eddy simulations. The objectives of these simulations were threefold: to study low-frequency unsteadiness of the shock- wave/separation system, create a method provide data for modeling efforts, and to set the ground work for studies of flow control. Four computations were performed, a highly resolved 24° degree compression ramp, and three reduced-resolution cases at ramp angles of 24°, 25°, and 26°. The reduced-resolution cases were run for extended durations to capture many cycles of low-frequency unsteadiness. All computations were performed at a Mach number of 2.25. Basic flow characteristics, such as boundary layer statistics, wall pressure, and skin friction profiles, were computed for each computation. Frequency spectra were calculated to confirm the presence of low-frequency unsteadiness and to create a base- line for future flow control computations. A separation-centered averaging method was introduced to assist in the creation of models. This method created a new do- main that moved as the initial separation location moved. The upstream causes of shock-wave/separation unsteadiness were also investigated. By comparing the tur- bulent boundary layer to the motion of the shock-wave, relationships between up- stream structures and the unsteadiness were developed. Low-frequency unsteadiness was found to be related to large structures near the wall. Finally, recommendations about domain size and boundary layer trips were given, and future work discussed.
Degree
M.S.A.A.
Advisors
Poggi, Purdue University.
Subject Area
Aerospace engineering
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