Vortex Shedding
 

Hi,

I've beent rying to model flow over bluff object to observe vortex shedding but havn't been able to achieve it. I only get one vortex at the beginning and then the system goes into steady state. I used 'Implicit unsteady', 'k-epsilon', 'RANS' and default settings for the time steps. The other parameters are as follows,

Velocity - 10m/s
PipeDiameter - 0.5m
Cylinderdiameter - 0.2m

Can anyone tell me where the problem might be?

The default time step is too large. Your mesh might be too coarse.

Hi!

Fisrt : check if under implicit unsteady you are using the second order scheme discretization!

Second: Check if the lateral boundaries are periodicities!

Third: Estimate the frequency of vortex sheding based on the Strouhal number (0.21) and set the time step to be at the most 1/10 of the computed period!

Regards!

Also use LES or DES. RANS methods are not very suitable since your time step is to small...

Thank you all for the reply.. I got it...