[Vino]

Hi,

I have used a new weight for calculating derivatives and I am using the new derivatives to reconstruct the variables. I am finding oscillations near wall in pressure plot. I would like to clarify few things to understand whats going wrong.

1) How pressure at the wall is calculated? Is it directly extrapolated from the neighbor? Where is it done in the code? I am unable to find the it in Heat_Flux BC.
2) What should I do if I want to just extrapolate the pressure from interior domain?
3) What should I do If I want to keep the variables at the wall without reconstruction(1st order)?

Thank you very much.!!!

[hlk]

Originally Posted by Vino

Hi,

I have used a new weight for calculating derivatives and I am using the new derivatives to reconstruct the variables. I am finding oscillations near wall in pressure plot. I would like to clarify few things to understand whats going wrong.

1) How pressure at the wall is calculated? Is it directly extrapolated from the neighbor? Where is it done in the code? I am unable to find the it in Heat_Flux BC.
2) What should I do if I want to just extrapolate the pressure from interior domain?
3) What should I do If I want to keep the variables at the wall without reconstruction(1st order)?

Thank you very much.!!!

Thank you for your question.
Since the problem is solved in terms of the conservative variables (density, momentum components, energy) the pressure does not need to be set directly. It is calculated in terms of the conservative variables elsewhere.
To extrapolate terms from the interior, use the normal neighbor. Accessing information from the normal neighbor is done in several places in the code, including BC_HeatFlux_Wall.

[Vino]

Thanks for your answer. I forgot to mention that it is for Incompressible(AC). Here pressure is treated as explicit variable (p, u, v). I will try your suggestion. Thanks.