[aymen_a22]

Hi,

I am carrying out an analysis on a turbocharger compressor wheel to compare it with the compressor map given for a specific compressor.

I have created a geometry of the compressor wheel using Blade Gen and have imported it into TurboGrid to create a mesh.

I am assuming constant mass flow rate and I am also assuming no pre-whirl.

I am unsure of a few things:
1: What turbulence model should I be using for the most accurate results?

2: How would I go about improving the mesh quality?

3: I know ambient temperature and pressure and would like to calculate outlet pressure, temperature and velocity. Is this possible?

4: I have not taken into account the diffuser as I do not know how to. How would I go about this as from what I understand, the pressure increase is a result of the diffuser (nozzle), the compressor wheel only pumps to increase the velocity.

5: How do I take into account the rotating compressor wheel as Turbogrid only imports one blade?

If anyone could help it would be greatly appreciated.

Kind regards.

[dklastiwka]

1: What turbulence model should I be using for the most accurate results?
-This is a question all CFD analysts always have. Best thing to do would be to try different ones and compare to experimental data. If you can't do that look up some papers and see what other people have done.

2: How would I go about improving the mesh quality?
- Remesh with smaller cells and closer to the walls

3: I know ambient temperature and pressure and would like to calculate outlet pressure, temperature and velocity. Is this possible?
- Yes it is with CFX post

4: I have not taken into account the diffuser as I do not know how to. How would I go about this as from what I understand, the pressure increase is a result of the diffuser (nozzle), the compressor wheel only pumps to increase the velocity.
- Pressure would increase in a diffuser if the velocity is subsonic. You will need to modify the geometry to add in the diffuser.

5: How do I take into account the rotating compressor wheel as Turbogrid only imports one blade?
-What is the ratio between the stator vanes and compressor blades. You may be able to use periodic BCs with a rotating reference frame.