[a.mahmoud]

I have a problem where I am required to simulate the flow through a reconstructed geometry of a human vessel (pipe flow), where the pressure at the inlet and at the outlet is known, in order to find the resultant flow rate.



My question is how should I set up a case in openFoam using the simpleFoam solver, where the pressures are the input and no velocity is specified. I have tried doing this by setting the velocity boundary condition to zero gradient at both ends, and the pressure as fixed value for both values, but the results were usually unstable and did not converge satisfactorily. I have tried with k-epsilon turbulence models as well as k-omega SST and even fully laminar, but none of them would converge.


What appropriate boundary conditions should I use and how can I improve the stability and convergence of the problem?


Thank in advance!