Radial compressor mesh guide
 

Hi all,

I am working on a radial/centrifugal compressor project and my part is the CFD design. I've done CFD before but nothing this complex. Essentially I am trying to gather literature on:

1. Meshing techniques, particularly this actually!
2. Turbulence models
3. Boundary conditions

And anything else someone may think is useful.

I was hoping to find actual papers or texts, for example a text analyzing different mesh densities, elements, shapes etc.. Whether K-E or RNG model is better etc..

Any help would be much appreciated.

Brett

Hi Brett,

The physics simulated in rotating machinery and in high-speed turbomachinery specifically is quite complex but there are packages and solvers (commercial or open) that can handle by design these configurations. Of course, the engineering choices are more or less up to you but there are best practices included in these packages regarding boundary and flow conditions.


I think a very good resource for modelling these flows can be found in CFD-Wiki:

http://www.cfd-online.com/Wiki/Best_...omachinery_CFD

At the bottom of this page, you can also find the papers on which the best practices are based on. For radial compressors specifically, you can take a look at the centrifugal compressor section of the ASME Turbo Expo papers in each year. Normally, the papers there are quite practical with good information.

In terms of meshing, as you can see in the appropriate section of the page linked above, multi-block structured meshes are preferred in the turbomachinery community as they normally more accurate and provide better boundary layer resolution than unstructured grids.

There are commercial packages that create meshes for turbomachinery more or less automatically (Autogrid5 from NUMECA, Turbogrid from ANSYS, Pointwise) but each with different capabilities. Unfortunately, I am not aware of any open-source or free packages that can create multi-block structured meshes automatically.

Hope this helps,

Thanos

(Full disclosure: I am currently affiliated with NUMECA)