How to connect Fliud and Solid in a heatsink
 

hi every body

i intend to simulate the 3D turbulent air flow in a heat sink exposed to a constant heat flux of its lower surface. i sketched the model in Gambit and defined boundary condition types. i "connected" all the vertices, edges and surfaces to connect the solid and fluid parts.
fluent gives a temperature distribution over the sink, but dose not solve for the fluid
i can not get the problem, can any one give me a tip?

Regards