EFFECTS OF BLEED SLOT SIZE ON THE SHOCK- WAVE/BOUNDARY-LAYER INTERACTIONS IN A TRANSONIC COMPRESSOR STATOR

A numerical investigation of shock-wave/boundary-layer interaction in a transonic compressor stator with different slot widths is presented in the current work. The fluid in boundary layer is bled through the suction slot into a plenum to control the separation. Three different slot widths at inlet Mach number of 1.0 are studied. Numerical results show that all sizes of slot are capable of reducing the total pressure loss coefficient. The maximum amplitude of decline in pressure loss is 75.7% compared to the cascade without bleed. The optimum bleed pressure and corresponding optimum bleed mass in terms of minimizing pressure loss appear in three different slots. The wider slot leads to a lower pressure loss at the optimum bleed pressure. The shock wave on the suction surface is reorganized by the slot bleed. At the same bleed pressure, the wider slot causes the modified shock wave closer to the downstream. The expansion in front of modified shock wave could change the flow direction over slot. The tangential momentum of boundary layer at slot downstream edge is increased by the slot bleed. This enhances the ability of the boundary layer to withstand the adverse pressure gradient.