I am working on flow around square cylinder using Fluent. First I got steady state solution using ske model. Then I switched to Unsteady with time interval 1/20 of expected shedding period. I am not getting periodicity in the contours of vorticity or static pressure. Anybody help me in this regard.

You can try laminar-unsteady model.

Thanks Muhammad

I tried using laminar-unsteady model following the steps given in tutorial for a circular cylinder given in studentfluent.com. But still I am not getting the vortex shedding when I use sk-e(2d) with standard wall functions.

Thanks once again.

then ask fluent engineer

You should make the mesh very fine. It works for me.

Thanks Jeffery822,

Initially my mesh included 12000 cells. I tried with 60000 cells now. But after few 100 time steps, the lift coef. converges/stabilises to 0. I feel I might be doing something wrong at basic level. Here are my problem details:

1) b = 0.06m; U = 5.356 m/s with 2% turbulence intensity; Fluid = Air; So Re=22,000 2) problem domain is 21b in streamwise direction and 15b in other direction. 3) Standard k-e model, Standard wall functions with first node from wall being at 0.02b 4) Time step 0.004 s (i.e. (1/20) of shedding period of 0.08 s) 5) Velocity inlet, Pressure outlet and periodic boundary conditions 6) Applied a patch of Y-velocity equal to 1m/s and -1m/s in the top and bottom regions of wake, respectively.

Could please throw some light becasue you mentioned that the problem worked for you.

Thanks once again

you will get ...contact me later

Thanks Sujay.

I did get the vortex shedding when I reduced the eddy viscosity ratio at velocity inlet boundary.

You can post any further technical information in this regard.

Thanks once again.