# Similation with jadim - coarse mesh

Firstly, a coarse mesh and real parameters of fluids  are applied to simulate the flow with VOF method by jadim software.

However, the simulation is not reasonable because the water and oil is mixed.  This could be caused by the high Reynolds number or the density of mesh. Therefore, the inlet velocity is decrease and the viscosity is raised for the simulation.

 $$\rho_{water} /\rho_{oil}$$ (kg/m3) $$\nu_{water} /\nu_{oil}$$ (Pa.s) $$\sigma_{oil/water}$$ (N/m) $$dt_{min}/dt_{max}$$ (s) inlet/outlet lenght (m) inlet velocity (m/s) mesh size (m) mesh size (cells) inlet Re 1000;800 0.1;1 0.025 0.1e-7;0.1e-4 0.02;0.05 5 0.45*0.35 90*70 200

This time, the phenomenon of diffusion is not as severe. But the mixture of the two phase still happens.

Thus, to avoid the diffusion, we need to use:

-a higher value of viscosity (100 times) to avoid this situation.

-a refine mesh.

 $$\rho_{water} /\rho_{oil}$$ (kg/m3) $$\nu_{water} /\nu_{oil}$$ (Pa.s) $$\sigma_{oil/water}$$ (N/m) $$dt_{min}/dt_{max}$$ (s) inlet/outlet lenght (m) inlet velocity (m/s) mesh size (m) mesh size (cells) inlet Re 1000;800 2;20 0.487 0.1e-7;0.1e-4 0.02;0.05 2 0.45*0.35 90*70 20 1000;800 2;20 0.487 0.1e-7;0.1e-4 0.02;0.05 5 0.45*0.35 90*70 50

With the viscosity of the fluids 1000 times of the initial values and Reynolds within 100, the calculation finally reaches convergence. Below is the initial and final state for the Reynolds 50.