creating CFX mesh
 

I have a question concerning more ansys workbench v9 than CFX module.I have to simulate the 3D heat transfer among heating parts inside a box and internal-external walls through a fluid. I've created firstly a fluid as a solid element with FIll command, then I've frozen all the parts and with body operation->slice material created the intersection. Is it the proper way? Is there any difference between slice and cut material in frozen/unfrozen mode? and is it really necessary to freeze the parts? Then I exported the model in CFX-Mesh, having difficulties with volume generation: probably it depends on the complex geometry. I found only this notes on the help documentation. Is there a simpler way to simulate the presence of a fluid inside a box, without incurring in such intersection difficulties? The problem is also the asymmetry of the model I have to study. Thank you in advance! Eng. Igor Di Varano,Italy