Investigation Of Separation And The Characteristics Of Multi-Vortices Flow On Double-Delta Wings

In this paper,a numerical investigation of characteristics of a 76°/40°double-delta wing and a 80°/65°double-delta wing in plain configuration and another with a central body is presented. The 3-order WNND scheme and the AF-ADI method are respectively applied to the discrete of the spatial and time derivative of the N-S equations.The computational results of the 76°/40°double-delta wing shows that:The Re Number doesn't affect the formation of the separation vortices,but it has an influence on the formation and distribution of those viscosity related structures,such as secondary vortices;Numerical simulation of the double-delta wing is sensitive to the computational grid,especially the distributing of pressure on wing surface is seriously depended upon the distance between the floor of the grid and the surface of the double-delta wing;on surface of double-delta wing,the strake vortex and the wing vortex is almost independent in low angle of attack,when in moderate attack angles,benefited with reasonably interference between vortices,the vertical flows become more stable,high angle of attack will lead the burst of vortices to occurred on the wing surface, vortices interact with each other fiercely,even to induce the strake vortex and the wing vortex to rotate together.The investigation of the 80°/65°double-delta wing shows that:result of numerical simulation can be effectively improved by computing with doubled grid in latter zone;with the influence of central body,the computed position of separation vortices placed more outboard than the situation of the plain double-delta wing,drag obviously increased and the lift features is also affected.