Geometric Effect on Compressible Rectangular Cavity Flows.

Abstract

Experiments were performed to study the geometric effects on the compressible rectangular cavity flows at Mach 0.33, 0.62, and 0.82. Typical characteristics of mean surface pressure distributions show a slight pressure variation near the front face, a local peak surface pressure ahead of the rear corner, and a low pressure immediately downstream of the cavity. The length-to-width ratio of a cavity has a strong effect on the recompression and downstream expansion near the rear face, and the Mach number effect is minimized. Surface pressure fluctuation distributions show a damping near the leading edge at a higher freestream Mach number, a minor peak near the middle of the cavity floor, an increase toward the cavity rear face, and a peak value immediately downstream of the cavity. The amplitude of the pressure fluctuations ahead of the rear face increases with the length-to-width ratio for transitional-and closed-type cavity flows, and the maximum of peak pressure fluctuations rises rapidly for the transitional cavity flows at higher length-to-width ratio.

Use of Active Learning to Design Wind Tunnel Runs for Unsteady Cavity Pressure Measurements

“…It is widely acknowledged that wind tunnel testing is essential in characterizing flow across a cavity. A number of parameters can influence the flow including freestream Mach number, geometric dimensions of the cavity, and location of stores within the cavity [1,4,5]. The number of parameter combinations and requisite data reduction can render wind tunnel testing tedious, expensive, and time consuming.…”