Numerical Investigation of Dorsal S-Shaped Inlet Flow Characteristic and Effects of Related Parameters

Abstract

The air intake design system of the dorsal intake combined with the S-shaped inlet has been widely used in various combat aircraft due to its good stealth characteristics. In this paper, the numerical simulation of the flow characteristic and influence law of various parameters for a typical air intake design with dorsal S-shaped inlet was carried out using the in-house large-scale parallel computational fluid dynamics (CFD) solver. Firstly, the numerical method was introduced and the solver was preliminarily validated by the well-known RAE M2192 inlet model. Then, the numerical calculation of the target air intake design was conducted and the distribution of shockwave at the entrance area, the second flow in the inlet and the flow at the exit section plane were analyzed in proper order. In addition, the influence of the bump height and lip sweep angles on the inlet performance was also studied. The simulation results show that the unique S-shaped design in the inlet will result in flow separation and secondary flow, ultimately causing total pressure loss, and different external geometry parameters have a great influence on the inlet performance. Within a certain range, proper reduction of the bump height or lip sweep angle can improve the inlet performance.