sliding grid problem
 

hi,

I am trying to simulate conventional stirred tank reactor, in which the liquid is sparged form bottom and the reactor consists of the bulk liquid and with impeller

for the impeller motion i have created sliding grid by creating two interface at the same place near the impeller with in the reactor.

but when the simulation is run the velocity profile for the bulk liquid results in zero value

and i doing unsteady simulation using fluent 6 version

do anyone have any idea...regarding how to deal with this problem