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-   -   Pressure field fluctuation in y and z directions (https://www.cfd-online.com/Forums/openfoam-solving/217859-pressure-field-fluctuation-y-z-directions.html)

Rasmusiwersen May 27, 2019 13:20

Pressure field fluctuation in y and z directions
 
Hi all,

I am experiencing some irregular fluctuations in my pressure output from OpenFOAM. More specifically, the y,z direction pressure measurements fluctuates quite a bit at random times, when the x direction does not.

Example is shown here: https://ibb.co/445hh5m , which is the y-direction component of the pressure.

I have performed several other simulations of the exact same model, where the only thing i've changed is the velocity Um, and they worked fine. I don't know which dictionaries you might need in order to help me, so please ask me, and i will upload it straight away.

Hope some of you can help.

kagen816 August 11, 2021 09:48

Hi Rasmus,

May I ask if you have found the reason? I am experiencing the same strange pressure fluctuation behavior.

Best

Rasmusiwersen August 11, 2021 10:27

Quote:

Originally Posted by kagen816 (Post 810109)
Hi Rasmus,

May I ask if you have found the reason? I am experiencing the same strange pressure fluctuation behavior.

Best

Hello Kagen816,

I don't recall exactly, but my end results did not show this behaviour. I found that irregularities like the are often associated with the diacretization in either time or space. In my case I am pretty sure it was in space. So different og higher refinements near the structures or a larger domain all together. Too small domains can result in blocking effects, which you do not want.

Hope this helps, although it is a timely effort to reduce the fluctuations.


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