Cosmos Floworks: Rotating Impeller

[ugnuck]

Hi to all,
I have a big problem here. I tried to simulate a radial pump with a rotating impeller ( more or less like the impeller in the tutorial). But the results I get make no sence. First of all it seems as if the impeller is running in the wrong direction, although I changed the rotating direction by setting a minus in front of the RPM and after this didn´t work changing the reference coordinate system.
Second, during the calculation a neg. pressure occurs and in the inlet there is a vortex.
I hope someone knows how to handle this.

Thanks ugnuck

 

[solid34works]

Could you please let me know where are those tuturial?

Thanks,
Robin

 

[ugnuck]

You can find the tutorial in the solidworks folder. As I don´t know in which folder you copied solidworks here it is for the C drive.
Try this with the explorer: C:\SolidWorks\COSMOS\FloWorks\lang\english\Docs

In this folder you will find three documents as PDF-Files.

I hope this could help you.

Ugnuck

 

[cbrn]

Hi,
first of all, and excuse me if it sounds trivial, is the "rotating frame" checkbox activated? Then, are the "rotating" surfaces correctly defined? In fact, as the rotating frame is banally a matter of relative velocities, if by chance you selected the statoric surfaces as rotating, everything will always be "reversed".
As for the pressures, bear in mind that the calculation is always "relative", that means it proceeds with the equations of energy conservation from a "total pressure" the fluid has at the inlet. You can tell the system the "real" total pressure of the fluid if you know it, but more in general if you are interested in the energy "gain" given by the impeller you can tell the system that the fluid has arbitrary total pressure (i.e. energy) at the inlet. This may avoid some "negative pressure" issues. In fact, FloWorks, afaik, can not detect cavitation etc, so the search for "extremely realistic" situations is pointless.

Regards