Akademik Veri Yönetim Sistemi
JOURNAL OF SPACECRAFT AND ROCKETS, cilt.33, sa.3, ss.353-359, 1996 (SCI-Expanded)
Hypersonic flow over the nose of a blunt body with a forward-facing cavity is studied both experimentally (Mach 5 blowdown tunnel) and numerically (commercial finite volume code). Trends are established for the pressure oscillations within the cavity, flowfield structure, and surface heating for different cavity depths and lip radii. Resonant pressure oscillations within the cavity are an experimental flow feature but occur numerically, for the cavity geometries studied, only if freestream fluctuations are present, The oscillations are dominated by the quarter-wave frequency of the cavity, In the numerical simulations, the oscillation strength increases with cavity depth. In the experiments, oscillation strength generally increases with cavity depth; however, for a specific midrange of cavity depths, experiments show that the pressure oscillations switch randomly between two modes of behavior involving small- and large-amplitude fluctuations, Agreement between experiment and computations is good for the flowfield structure and surface heating of shallow cavity flows. Sharp lips produce both a recirculation region that cools the outer surface, and severe heating just inside the cavity, Rounding the lip eliminates the recirculation region and alleviates heating inside the cavity, Experimental results show that the strong oscillations associated with deeper cavities may produce a cooling effect.