Aerodynamic analysis and validation by using three turbulence models for narrow trench configuration

Three turbulence models SST Gamma Theta, k-omega and k-epsilon which all found in ANSYS CFX were used. Velocity contours, pressure coefficient profiles and turbulence levels contours were discussed. Results indicate that three models calculated the cross flow boundary layer with different thicknesses. This leads to a difference in calculation each the momentum of the cross flow fluid closer to the jet exit and cooling performance. At M = 0.5 from range X/D = 5:40, the average centerline effectiveness values in case SST Gamma Theta model and k-omega model were 21 and 9.2 % larger than k-epsilon model, respectively. While at high blowing ratios 1 and 1.4, the effectiveness values in case SST Gamma Theta model and k-omega model were 16, 24.4 % and 32, 46 % less than k-epsilon model, respectively. k-omega model shows a larger backflow regions than others which a maximum negative value of u/u(a) = -0.198 is reached in zone 4.