p equation solver in channelFoam
 

Hi,

I just encountered a problem about the p solver in channelFoam. In the tutorial, the p solver is using PCG, which is only valid for symmetric matrix, so my question is, how can we determine if the matrix is symmetric or not? does it mean the simulation problem is symmetric? sorry, I'm a newbie in numerical simulation.

it's clear that p-equation is solving something like laplacian (p) = - div (U), so it may be clear that the p-equation will end up with solving a linear system with symmetric matrix, am I right?

and the reason why the momentum equations end up with solving asymmetric matrix is due to the convection term? please feel free to correct me if I'm wrong anywhere, Thanks!

Thanks!

Charlie