Numerical investigation of the effects of different leading-edge profiles on vortical flows over a double-delta wing

In this paper, the effects of different leading edge profiles on vortical flows over a double delta wing with sweep angles of 80/60 degrees were widely investigated numerically. To simulate the complex flows over double delta wings with different leading edge profiles, a high resolution upwind flux difference splitting scheme was used to solve the 3 D compressible unsteady NS equations. The three different leading edge profiles were round, single sharp and double sharp. The results showed that different leading edge profiles could induce different forms of separation and that the induced shear layers are also different. The combination of the inner and outer vortices resulting from single sharp profiles happens earlier than those resulting from double sharp profiles and round profiles respectively. At high angles of attack, for instance 35 degrees, the vortex breakdowns can be visualized over all the three kinds of wings. The effects of the vortex breakdown on the structures of the secondary vortices were also discussed in this paper.