Numerical Study of the Ratio of Depth-to-Print Diameter on the Performance and Flow Characteristics for a Dimpled, Highly Loaded Compressor Cascade

The influence of the ratio dimple depth-to-print diameter (λ) on highly loaded compressor cascade NACA0065-K48 is investigated based Reynolds-averaged Navier–Stokes (RANS) method. Simulations are conducted with a validated shear-stress transportation (SST) turbulence model coupled Gamma-Theta (γ−Reθ) transition at inlet Mach number 0.7. At 5~25% axial chord suction surface, four rows dimples arranged in parallel, and dimples’ spacing 4 mm. Moreover, there five kinds λ, ranging from 0.125 to 0.875, which determine pressed arc spherical dimple. Three flow regimes (diffuser–confuser flow, tornado-like vortex horseshoe vortex) same topological structure observed these dimples, affect performance by changing energy distribution. distribution turbulent kinetic (TKE) reflects disturbance inferior (λ=0.375) intensely, whereas superior (λ=0.625, 0.875) relatively weak. Numerical results indicate that loss corner separation can be reduced array, mainly related vertical climbing lateral delays starting point weakens mixing process. However, wake dimpled cascades increases, caused thickened boundary layer induced high vortices. λ=0.625 achieve most significant reduction (13.47%), while ensuring pressurization capacity.