Numerical Investigation of Roll-angle Effect of the Vortex Flow on Double-delta Wing

The Slightly Compressible Model(SCM) was employed as the control equations for low Mach number flow and was discretized by the spatial 2nd order Roe Scheme and LU-SGS scheme.The vortexes flow-fields of the 76/40-deg double-delta wing in fixed attitude with 20-deg nominal attack angle and varies static roll angle were presented.The spatial vortexes flow trajectories and the extreme surface streamlines were presented to illustrate the effects arose by roll-induced attack angle and slide angle,furthermore,the varieties of flow structures,surface pressure distribute,aero-force and aero-moment which were brought by these effects were analyzed also.The results indicates: the SCM can well predict the complicate vortexes flow-field of low speed double-delta wing with a nice performance of stability and convergence;static roll angle can lead unsymmetrical phenomena and burst of the leeward vortexes flow on double-delta wing,hence,lead reduction of lift force and slack of transverse stability.