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Hao Meng June 3, 2005 10:28

Pressure oscillation in time
Hi all,

I got a result from 1D gas-liquid flow computation that the pressure at interface oscillates in time.

Is the phenomenon right?

Could someone explain the phenomenon if it is right?

Thanks in advance!

Hubert Janocha June 4, 2005 06:20

Re: Pressure oscillation in time

I have a similar problem (please see my question and discrition on the StarCD User Forum "oscillations 1D3D coupling GT-Power/StarCD" dated may.05.

No, I think this oscillations are not right. That's a problem with the 3D-CFD-Software in general. I am seeking for good advice too. If you got one please let me know.

Hao Meng June 5, 2005 03:14

Re: Pressure oscillation in time
It is said that the phenomenon is non-phisical and the pressure error is produced due to the interface caputuring method. Interface tracking method will not produce such error.

But i am not clear the details.

Hubert Janocha June 5, 2005 15:35

Re: Pressure oscillation in time
Yes that's right. I don't know "interface tracking method", but it is an idea. In the mean time I have thought about the problem. In my case dependend on time I got very high and than very low pressure gradients. I use k eps tubr-model, and that could be a problem. I adjust the y+ cells to the recommanded values for my high speed flow, but in that time when the flow speed is low, the turb modell don't work correctly. A remedy is to use 2 layer models in that regions, so we can erase the error from the log wall law.

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