Characteristics of Transonic Rectangular Cavity Flows

Experiments are performed to study the characteristics of rectangular cavity e ows. Mean and e uctuating surfacepressurein a Mach-1.28 turbulente owpastrectangularcavitiesareobtained. Thecavity length-to-depth ratio L/D varies from 2.43 to 43.00, and the length-to-width ratio L/W is 0.5, 1.0, and 2.0. The effect of cavity depth is studied, in which L/W or both L/D and L/W are held constant. The results indicate that L/D is the most important parameter in determining the characteristics inside the cavity and in its vicinity. The effect of L/W is signie cant only at the aft half of the cavity. Lower static pressure aft of the front face and higher static pressure at the aft half of the cavity are observed with decreasing depth-to-incoming boundary-layer thickness D/±0 at constant L/W. At constantL/D and L/W, the results show an opposite trend. The amplitude of surfacepressure e uctuation decreases at larger L/D. The parameter L/W mainly affects the peak surface pressure e uctuation ahead of the rear face.