Numerical Analysis of Effect of Slot Geometry on Supersonic Air Inlet Performance

Various methods are used to control and attenuate the adverse effects of shock wave/boundary layer interactions (SWBLIs) and improve the performance of supersonic aircraft inlet. In this study, passive slot control is presented as a new, practical method for this purpose and its effect on supersonic inlet performance is investigated. To do so, a rectangular supersonic air inlet is first modeled and meshed at design Mach number of 2.2 and mesh independency is examined using three-dimensional (3D) computational fluid dynamics (CFD) method to achieve an ideal mesh; the most suitable mesh is selected to continue the work. The results of numerical simulations are compared with those of other studies and validated to ensure the correctness of the solution. In this paper, the inlet performance is first discussed without slots at design Mach number of 2.2 and, then, its performance is evaluated by creating slots and considering various parameters. The results indicated that using slots increased the pressure recovery and, consequently, enhanced the inlet performance in off-design conditions. It was also found that creating slots caused the vertical waves to reach the inlet with a delay and effectively controlled the flow. Then, after selecting the best slot, the inlet performance was presented and compared in off-design conditions at Mach numbers of 2 and 2.4, both with and without slots; finally, the best geometry was determined