Problem with non-drag forces
 

Hello,

i'm about to simulate a bubble column within my thesis. I'm studying the influence of different forces on the bubbles within the column. I'm using an eulerian-eulerian method with a continous phase water and a dispersed phase for the bubbles with a mean diameter of 3mm. The simulation are transient with high resolution settings.

I've been simulating without the drag forces for some weeks before, but the solver converged every time. Unfortunatley the no-slip condition for water phase isn't granted. After picking up some literature which claimed that negligence of wall lubrication forces can lead to violation of boundary conditions i changed some settings to check it up. I implemented Tomiyama model. The Simulation started as usual but it crashed after the first complete loop returning error code 1 (an error code without any information).

I began to play with the other non-drag forces implementing them in various combinations but the problem couldn't be solved. By removing the forces the solver converges but still violates the boundary condition. I'm unable to identify the mistake in my setup. I tried other turbulence models but without success.

Do you have some ideas or did you had similar problems? Every hint would be great :)!

First of all check the normal parameters for solver stability: Double precision numerics, better quality mesh, smaller time step, better initial condition. Check these are OK first.