Home › Forums › Questions

pressure range

Submitted by navvabk on January 31, 2012 - 06:05

I am facing an strange problem and don`t know the reason.

The pressure contour range varies between -3517.9,+23798 N/m2 in my simulation for a complex geometry. When I export the results to Tecplot, the range is [-6.5,+2]. Would you tell me what may cause this problem?

Thanks a lot!

‹ Section planes Caedium and Moving mesh ›

Not sure

Submitted by symscape on January 31, 2012 - 08:27.

Is this for an incompressible flow? If it is, then the pressure range in Caedium looks too large.

For incompressible flow in Caedium the pressures you specify and the pressures reported are gauge pressures (relative), did you enter an absolute pressure when it should have been a gauge pressure?

In terms of the different scales between Caedium and Tecplot - what are the units in Tecplot? Still N/m2 or is there a scaling applied (e.g., kPa)?

The range maybe different if Tecplot is reporting for the whole flow field whereas Caedium will only report the range for the entities you display. Another difference (though I doubt it would account for such a variation) could be whether you are looking at node or cell values.

Yes, this is for an

Submitted by navvabk on February 1, 2012 - 03:26.

Yes, this is for an incompressible flow. There is one inlet (known flow rate) and one outlet. I have not included any pressure.

Actually there is no scaling in Tecplot and the unit should be N/m2. I am dealing with pressure contour in the whole domain both in Caedium and Tecplot.

Any idea?
Thanks a lot,

Tecplot reporting pressure/rho

Submitted by symscape on February 2, 2012 - 07:35.

Thanks for sharing your case. My mistake I presumed you were simulating air, not water.

I think the difference in pressure values you are seeing is because Caedium reports pressure (N/m2), whereas Tecplot is reporting the primary variable used in the OpenFOAM simpleSolver which is pressure/rho (m2/s2).

You are right. Thanks a lot.

Submitted by navvabk on February 3, 2012 - 04:01.

You are right. Thanks a lot.

Try OpenFOAM import in Tecplot

Submitted by symscape on February 2, 2012 - 07:43.

Another thought - Tecplot now reads OpenFOAM directly, so instead of exporting to Tecplot from Caedium, try exporting to OpenFOAM and then use the native Tecplot OpenFOAM import. This way Tecplot might be able to better interpret the units of the primary variables.

Thanks for the suggestion.

Submitted by navvabk on February 3, 2012 - 04:02.

Thanks for the suggestion.

I can take a look

Submitted by symscape on February 1, 2012 - 07:44.

I can take a look at your Caedium project file (.sym) if you can share it. Use our contact form to provide a link to your simulation via Dropbox.

Feedback

Questions? Ideas? Problems?

Forums

Newsletter

more