[mostanad]

Hi everyone,
I am struggling with a fictitious domain (immersed boundary method) for solving fluid/solid interaction in Newtonian and non-Newtonian fluids. The algorithm for Newtonian fluid in just one iteration is as follows:


1- Solve the entire domain without considering solid object using PISO solver (fictitious domain)
2- Imposing solid object velocity in domain
3- Solving a Poisson equation for satisfying continuity once again.
4- Finally based on the obtained velocity and pressure field, the drag force on solid object is obtained.


The problem for me appears when I switch the algorithm for a power-Law non-Newtonian flow. As I understood, the first step in the algorithm does not work using PISO. When I utilize PISO algorithm, the critical problem is with pressure field. So a solver like PIMPLE with URF works for the first step. So the first step obtains the fluid field, but due to the outer iterations in pimple solver, the imposed particle velocity is forgotten in next time step. Therefore, the force on solid object in non-Newtonian fluid fails. So is there anyone interested in having some CFD discussion about pimpleFoam and non-Newtonian fluid?
Cheers,
Mohammad