Effects of trailing wall modifications on cavity wall pressure

Abstract

Six different trailing edge ramp modifications were implemented for a range of baseline cavities with length to depth ratio, L/D, of 2, 3, 4, 6 and 8. The ramp angles were varied at 30°, 45° and 60° and ramp heights were varied at 0.25 times and 0.5 times of cavity depth. The objective was to study the effects of trailing edge ramps modifications on the wall pressure of cavities, how these affect the pressure drag within the cavity and the moment about the cavity floor. The ramp angle of 30° was successful in reducing the cavity floor moment for L/D=2 and 3 but brought about adverse effects on the cavity floor for L/D=8. In L/D=2, the ramp modification of ramp angle 30° and ramp height 0.25 times of cavity depth achieved the best pressure drag reduction of 83% against the baseline case; while in L/D=3, 4, 6 and 8, the ramp modification of ramp angle 30° and ramp height 0.5 times of cavity depth achieved the best pressure reduction of 60%, 31%, 40% and 38% against the respective baseline cases.