How to write a CFD code for cylinder wake?
 

Hi all,

I want to write a code for the wake flow behind a cylinder. Where should I start? (Of course, the cylinder.) I knew I should use the immersed boundary method. Do you have a tutorial code or reference where I can learn? Thanks.

Shu

It all depends on your previous experience with CFD codes. Asssuming you are new to the field, I would greatly suggest you to work the 2D case first. Going with the simplest methods at first, you could try a finite difference. You could also start with a finite volume (which will lead you further then finite difference) using Versteeg & Malalasekera Introduction book.

Also, unless you have strong experience, forget about turbulence modelling until you have strong results for inviscid and laminar flow.

Immersed boundary (direct forcing) for your case seems indeed the simplest way to tackle this problem. It gives good results. Use finite difference too for simplicity of implementation.

Thank you both, Alex and leflix. I have some experience with FD, but new to immersed boundary method. I don't know where I should start. Could you recommend a textbook on IB method with simple hand-on code? Thanks.

Shu

I don't have bibliography on mind right now,but you should find many papers in Journal for Computational Physics related to this topic.
Many different methods exist but the most simple to my mind is the direct forcing method where you ensure the no slip boundary condition on the surface of the cyinder as well as on all nodes inside the cylinder.

Hi
Do you think that the ghost cell methode is a right choice to simulate a rigid cylinder inside a fluid ?
Thank you

It can give you acceptable results for laminar flows but in case of turbulence you need a very fine grid. You can find many papers for the IB method in several journals