Hi everyone,

I am simulating the vortex flow around a squared cylinder mounted a surface using Nektar++ incompressible solver. For this layout (see attached 1), the vortex wakes will become unstable and be shedding as Re >150. However, the current problem is that the computation cannot get the unsteady vortex shedding, it always converges to steady solutions even at Re=500. I even tried giving an incoming disturbance, but the flow fields still cannot converge to vortex shedding. The steady drag coefficients at various Re agree well with the time-averaged results in previous publications, but no vortex shedding occurs. I have simulated the vortex flow past a 2D cylinder, and vortex shedding can be obtained. But for the 3D case, the results are strange.

I attached the layout and grid file, and anyone can give some suggestions.  

Many thanks,

Baofeng

Baofeng Ma, PH.D
Associate Professor
Institute of Fluid Mechanics
School of Aeronautical Science and Engineering
Beihang University
Email: bf-ma@buaa.edu.cn
Tel: 0086 (0)10 82338344