Low Re flow past cylinders in tandem
 

Hello all

I am trying to simulate a low Re (Re=100) flow past two cylinders in tandem and I am unable to get vortex shedding which is quite obvious and also reported in literature. When I tried ANSYS Mesh unstructured mesh I was able to get proper results, but when I tried to make a structured mesh with ICEM CFD, I am unable to reproduce proper results. I must say that I am a newbie in ICEM and I have a hunch that my meshing is not proper. So I am attaching the image of my mesh. Kidnly suggest how to go about it.

Regards

with this mesh you cannot get any results, let alone vortex shedding :)

Create ogrid around both circles and run the solution.

Thanks Far.

I knew mesh was the culprit. However, I am not able to figure out how to create O grid meshing around 2 circles. I was able to do it successfully for a single circle. With 2 circles, when I try to split block around small circle, it intercepts with the larger circle. Kindly suggest any tutorials where I can learn about blocking for these kind of geometries.

Regards

which cylinder is upstream? smaller or larger?

Smaller cylinder is upstream and the gap between them is 1.2 times the diameter of the bigger cylinder.

In the mean time I tried creating two separate O grid blocks around 2 circles and it looks like this. I'm pretty sure it is not correct. Could you kindly suggest what changes I could make?

Could you please suggest how to make a blocking in this case? I'm not able to figure out perfect blocking strategy so far. Any help would be much appreciated.