Unmached boundary

keny

Hi All,

I am trying to model a stirred reactor in CFX4.4. I am using the slidding grid approach, where the impeller is moddeled as a moving block and baffles are as stationary block. Between the block I have unmached boundaries and periodic boundaries between the bafles and the inpeller blades (which form part of the inner block) -I have only one cell in the axial direction (K) -High K and low K are specified as symmetry planes.

When I run the solver, the convergence is poor with high oscilations. I get a warning message from the output file that: WARNING : THE TRANSIENT GRIDDING OPTION IS BEING USED WITHOUT A PRESSURE BOUNDARY THE FLOW HAS TO BE DEFINED CAREFULLY TO ENSURE MASS CONSERVATION

The top is a free surface, where do i go from here?. Can anybody help!!

keny