NUMERICAL SIMULATION AND VISUALIZATION OF COMPLEX SUBSONIC FLOW OVER A 65° DELTA WING

The VFE-2 65° delta wing with sharp leading edge in subsonic flows at Mach number of 0.4, angle of attack of 20.3°, and Reynolds number of 2×10⁶ is numerically simulated by using an unstructured hybrid mesh based flnite volume method, with emphasis on how to extract the key flow features for visualization both on surface and in space for such type of complex flows. Approaches for the advanced flow visualization techniques are used for qualitative and quantitative analyses, as a solid foundation for elaborated analysis of complex flow structures of delta wing. With these approaches, the complex vortex flow structure of the subsonic delta wing at high angle of attack is analyzed, and results are consistent with experiments. It is shown that the flow over delta wing at high angle of attack has a complex physical nature with a strong viscous coupling efiect, and the evolutions of the primary and secondary vortices can be accurately captured only by a Navier-Stokes equation based simulation.