Aerodynamic Analysis of Retractable Belly Flap for a Flying Wing Aircraft

Abstract

The study on the lift enhancement effect of the retractable belly flap on the flying wing configuration can conclude the effect rules on aircraft aerodynamic force. A flying wing configuration model is taken as the initial shape of flying wing configuration aircraft,the numerical simulation distribution method is used to select the types of crevices distribution on the retractable belly flap.And on this basis,the characteristic of aircraft aerodynamic forces under different retracted states of the belly flap is analyzed. The results show that the retractable belly flap,when it is fully extended,can effectively lighten the air separation behind it and enhance the lift. When the crevice width is the same as the width of the hill shaped rudder,the effect of lift enhancement is the best. The pitching moment shows a quasi-linear growth with the decrease of the height of the retractable belly flap during the belly flap retraction process. Moreover,the lift enhancement effect of the retractable belly flap is better than that of the seamless belly flap at the same height.

Keywords

• flying wing configuration
• belly flap
• retractable performance
• aerodynamic characteristics
• take-off and landing process