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Old   June 3, 2005, 10:28
Default Pressure oscillation in time
  #1
Hao Meng
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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!
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Old   June 4, 2005, 06:20
Default Re: Pressure oscillation in time
  #2
Hubert Janocha
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Hi,

I have a similar problem (please see my question and discrition on the StarCD User Forum "oscillations 1D3D coupling GT-Power/StarCD" dated 29.th 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.
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Old   June 5, 2005, 03:14
Default Re: Pressure oscillation in time
  #3
Hao Meng
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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.
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Old   June 5, 2005, 15:35
Default Re: Pressure oscillation in time
  #4
Hubert Janocha
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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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