[songyi719]

I have a bit confusing part about laplacian operator of openfoam, so I am writing the thread to ask some question


https://www.openfoam.com/documentati...laplacian.html


When we look at this guide, it says fvm::laplacian can be used as not only laplacian operator, but as combination of divergence and gradient. But since they mentioned diffusion coefficient as example, I initially thought it is actually meaningless, since it is meaningless to put constant coefficient before or after the gradient operator and has no difference.


However, I was trying to modify some scalartransport code, and I found that they use fvm::laplacian(rho*D(), s_) and rho is definitely non-constant operator. In this case, is it used as div(rho*D*grad(s))or just laplacian(rho*D*s)?



Can anybody give exact description of how fvm:: functions are used?