Numerical investigation on the effects of boundary layer ingestion on aerodynamic performance of distributed propulsion system

To explore the effect of boundary layer ingestion (BLI) on the aerodynamic performance of aircraft, the aircraft/engine integrated simulation method based on the streamwise-body-force model was used to calculate a distributed propulsion system. Results show that BLI mainly affect the flow field of center body parts and cowling of engines, but yield small impact on lift and drag of the blending field and outer wing of BWB. Under the same flying conditions and constant angle of attack, the lift coefficient and drag coefficient increase with the increase of the non-dimensional mass flow rate of the engines. Therefore, a best non-dimensional mass flow rate of the engines corresponding to maximum lift-to-drag ra-tio exists. Engine installation location directly influences the localized supersonic flow of fuselage surface and the shock wave distribution of cowling. Layout of engines at the trailing edge could get better lift-to-drag ratio, where the non-dimensional mass flow rate of the engines corresponding to maximum lift-to-drag ratio is 0.65.