Hi! I am using fluent for the modelling of a non-clogging centrifugal pump. It is outlined in my previous message. Anyway, I have a few more questions!! 1. I see from the fluent tutorial that in the case of a sliding mesh, 2 seperate geometries are created and meshed seperately. Tgrid is then used to merge these together in Fluent. Do I have to work in this manner, or can I create all the geometry in one gambit file? 2. If I can create all the file in a single file, then how do I define the grid interface? Do I need to? Or do I simply specify a rotation velocity?

Thanks again for any help, Jack.

I don't have any specific experience with FLUENT (Then why the heck am I responding?!?) but based on your questions, I presume that you are a new user, and I would recommend following the instructions in the manuals and tutorials. The tutorials will generally walk you through the best way that a new user should model a given situation (although probably not the only way).

In this particular case it makes sense that you would need to generate two independent grids with a common interface. The solver needs to "know" that different things are happening in the different regions of the model. In this case one portion is rotating and the other is stationary. By separating the grid into two different files, you can provide the proper input parameters for the analysis for each of them.

As for inlet and outlet conditions, a wide variety should be supported by the code. The list will certainly include perscribed pressure and velocity conditions. You need to decide what kind of BC is most appropriate for your model based on what is attached to suction side and discharge side of your pump. I have been involved with pump analyses that included a significant length of up-stream piping because the piping geometry affected the inlet flow distribution.

Hi... I'm a student from the swiss ingeneering school of Biel. Perhaps also known from the solar races in austrailia. I try to optimize a radial working pump. I still done a calculation with a single mesh. So the fluid zones were stationary and only the walls of the impeller gots the atribut of rotating walls. The result was, that the walls were turning but the water was just standing still. So I think I have to separate my grid in more zones, so that I can create moving meshs. The 3D- Geometrie is very complex and I can present you the first results perhaps next week...

...I hope that it will work....marcel

P.s...are you 2D or 3D ?