Setting normal gradient as BC
 

Hi all,

I am editing icoFoam for a specific calculation in which I want to set the normal gradient of a patch as a boundary condition.

So normally scalar field 'c' would be solved using the BCs for the values of 'c', but now I would like OF to use normal gradient 'dc/dn' as BC.

I know that 'c.boundaryField()[patch].snGrad()' would return the values of the normal gradient, but I'd like it vice versa.

Anyone know if this is possible at all?

Thanks in advance,

Hi,

You can use the fixedGradient boundary condition to set a patch normal gradient to a user-specified value.

Hope this helps,
Fumiya

Hi Fumiya,

Thanks for your reply. I was aware that this was the way to go for the initial conditions. However, I would like OF to do this for me as a BC that changes each timestep.

To give a bit more information: I am using an external solver that calculates dc/dn from other quantities. The goal is to set this calculated dc/dn as BC for the next timestep. Therefore, I need a way (be it a provided member function or a more elaborate method) to incorporate this in the solver itself.

Thanks,

Hi Dozer_94,

The following thread will be of help:
https://www.cfd-online.com/Forums/op...iteration.html

Fumiya

Thank you Fumiya, this was exactly what I was searching for. Seems like something I could have figured out myself, though.