I have a simulation for impact of a droplet onto a particle (axisymmetric vof).
I have created my Case an I need to study effect of droplet viscosity on impact outcome. So, I use the same case every time, but I change the liquid phase properties on it. As I increase the droplet viscosity, formation of the liquid film due to impact is getting hindered (which is expected based on the physics of the impact). However, as shown in Fig. 1, there is a return point for this behavior (happens around mu=10 cP) which is not expected (although there are papers reported a similar behavior which hinders liquid 'splashing' around the same viscosity mu=10).
Initially, I use '2nd order upwind' for the momentum equation. As shown in Fig. 1, when I changed it to QUICK, there is a significant difference between the results for mu=10 (as far as I know, QUICK is mostly good for the structured mesh, while I'm using unstructured).
Does anyone know which one of these solutions I should rely on?