9600318 Wang The International Research Fellow Awards Program enables U.S. scientists and engineers to conduct three to twenty- four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad. This award will support a twelve-month postdoctoral research visit which will support Dr. Frank Y. Wang to work with Professor Jean-Marc Charbonnier at the von Karman Institute for Fluid Dynamics in Belgium. This project involves investigating experimentally the dynamic stability characteristics of a reentry capsule and their relation to the downstream wake flow at low speed. Dr. Wang and Professor Charbonnier will measure aerodynamic coefficients of a capsule-like body, mean and turbulent quantities of the boundary layer and the downstream wake flows, and do flow visualization. An existing support system specifically designed for the investigation of the stability of capsule-like bodies will be used for both mounting the model and measuring its global aerodynamic coefficients. Shadowgraph/Schlieren visualization will be utilized as an initial step to globally characterize the wake flow. The flow diagnostic effort will then concentrate on the use of particle image velocimetry (PIV) to map out the boundary layer and wake characteristics. In addition, a parallel investigation of the flow fields using conventional miniature five-hole probes will be carried out to address the applicability of the PIV technique in this type of problems. The measurement of aerodynamic coefficients is crucial in providing the necessary information to ensure the safe return of astronauts. The detailed documentation of the boundary layer and wake flow fields will broaden the existing database for transonic blunt bodies, aiding the development and validation of computational models, as well as offering an unprecedented opportunity to examine the dynamic interaction between the flow over the capsule and its downstream wake. ***
