I read some paper, in the old version of COMSOL, we can choose a Mixed boundary condition (mix of Dirichlet, Newman and Cauchy conditions). in order to automatically transfer the boundary condition form pressure head to Flux, or Flux to pressure head.
But in the new version of COMSOL 4.2 or 4.3, I can not found that kind of setting, could anybody tell me how to define a mixed boundary condition, for complex infiltration problem. The situation is, if the flux is very large, the surface boundary condition is set initially a Flux boundary condition, but once the surface pressure head is larger then 0, then the boundary condition should transfer from Flux boundary condition to pressure head boundary condition.
Could any expert have some suggestion? I appreciate for your help.
But in the new version of COMSOL 4.2 or 4.3, I can not found that kind of setting, could anybody tell me how to define a mixed boundary condition, for complex infiltration problem. The situation is, if the flux is very large, the surface boundary condition is set initially a Flux boundary condition, but once the surface pressure head is larger then 0, then the boundary condition should transfer from Flux boundary condition to pressure head boundary condition.
Could any expert have some suggestion? I appreciate for your help.