Learning Forum

[Ammar Ahmed]

Hello everyone, 

I am modelling flow through C-D nozzle in 3D. For this I have 2 Fluid Domains and 1 Solid Domain. 1 Fluid domain is used to produce supersonic flow and the other fluid domain has coolant in it which cools down the solid present in between the fluids. I am having confusion with specifying the wall thermal conditions as I want to see how much coolant can cool down the solid walls. For this I am using mass flow rate inlets and pressure outlets. Both flows are counter flow. For now i am giving solid walls, as following. The problem i am facing is that proper heat transfer is observed and proper temperature contours are not developed . Kindly help me out to define the wall thermal conditions properly.

[Rob]

Depending on how thick the solid is you may find a thin wall & shell conduction will be sufficient. Walls between zones should be "coupled" and have a wall & wall:shadow pair of labels. If you don't have these then Fluent has no way of passing information from one zone to the next. 

Read up on "Share Topology" in SpaceClaim. 

[Ammar Ahmed]

I do have that but the issue is the tempreture distribution in the inner domain is not similar to when i perform seperately with one fluid domain only. I have problem in defining the wall thermal condition. Kindly also tell if we have to assign any thermal conditions to the walls of fluid.

[Rob]

The wall & wall:shadow pairs should be left as coupled. Fluent will handle the HTC from the fluid to solid, and all conductivity within the solids. You only need to set the outer wall bounday conditions.