Numerical simulation of vortex breakdown onset

Based on an improved inviscid multiple line-vortex model (MLVM), numerical simulation for vortex flows over a pointed-nose body of revolution at high angles of attack is used to study the vortex breakdown onset. The result indicates that vortex breakdown occurs at angle of attack 38° with the special initial locations of the free vortex lines given, which coincides with the result of flow visualization in a water tunnel. The calculations also show that the adverse pressure gradient may be one of the reasons which result in vortex breakdown.