Effects of cowling design on aerodynamic performance of airfoil with BLI

Boundary layer ingestion (BLI) effect significantly influences aircraft aerodynamic performance. Cowling design further affects aerodynamic performance of airfoil with BLI effect. To clarify the effect and its reason of main cowling design parameters on aerodynamic performance of an airfoil with BLI effect, a detailed study was investigated by computational fluid dynamics (CFD) method and Morris sensitivity analysis method. Sensitivity order and coupled effect order of main parameters on aerodynamic performance were obtained. Flow details of parameters with higher sensitivity and greater coupled effect were analyzed. The results show that in cruise and take-off conditions, the parameters with relatively great impact are cowling maximum thickness and inlet location along the chord direction. The main reason of effects of cowling maximum thickness on aerodynamic performance is that local stall occurs at cowling surface. The variation of cowling maximum thickness also affects the variation trend of plot of drag coefficient to mass flow rate. The coupled effect of cowling maximum thickness and inlet location along the chord direction on aerodynamic performance is relatively great.