coupled wall problem
 

Hi every one....
my problem is simple...there is a cube filled with highly viscous liquid on which a cylinder is placed.(cylinder diameter is less than the cube's side). This cylinder rotates at 1500 rpm. so bcos of shear and viscous dissipation, heat is generated. So in fluent, at cylinder-cube interface, i've created a coupled wall. On that coupled wall i specified some heat flux value. Some part of this flux should be transferred to cube and rest to cylinder.
Problem is that, after some iterations, in temperature contours, i can see that some heat is transferred to cube , then it remains const (i.e., heat does not get transferred further) while conduction in cylinder is normal...

any reply would be appreciated.