[harshavardhanps383]

Good day,

I conducted a simple square duct (0.3 m x 0.5 m) simulation using air as the working fluid. The boundary conditions included a mass flow rate at the inlet and pressure at the outlet. The k-omega SST model was used for turbulence with a fine mesh having the first cell height at 20 microns, and the simulation converged well. However, when I switched the working fluid to water, the simulation diverged.

I used P-V coupling with a coupled solver and turbulence quantities with a second-order scheme. I also tried decreasing the relaxation factors. I have confirmed that the working fluid was changed in the cell zone conditions.

Flow velocities were 75 m/s for air and 2.5 m/s for water.

Any assistance would be greatly appreciated.