Strouhal Number of a square cylinder not matching
 

I trying to do a 2D model of the square cylinder for a Reynolds number of 50000. I am using the K-omega SST model. I have satisfactory results with the drag and lift. However, I am having some discrepancies in Strohaul's Number. I am getting a number of 0.08, whereas the expected number is in the range of 0.12.
Hope you can help.
Thanks in advance.

Frequency
 

Drag and lift are not much affected by the resolution but frequency is. A higher frequency requires finer resolution. You need to check if you are using fine enough temporal as well as spatial resolution to resolve the frequency for St of 0.12.