Learning Forum

[Bassil Bassil]

Hello everyone
I'm having some problems with the temperature in fluid flow (fluent). I am running a simulation for a counterflow double pipe heat exchanger but the fluids in both the inner pipe and annulus should be fully developed so on a different file I made the boundaries periodic and wrote the x y z velocity profiles of the 2 fluids after running the simulation with the energy off in "models". In the new file, in the setup, boundary conditions, I am choosing "velocity inlet" for the hot and cold inlets, and in the edit I am letting Ansys read the velocity profiles. I am choosing the hot inlet to be 433 K and cold inlet to be 403K. For both outlets I am choosing "outflow". When I am running the simulation I am not getting a heat transfer between the fluids and walls and thus, it is not converging. What should I do to make it work?

[DrAmine]

Inner and outer fluid domain: are they connected properly? Can you perhaps issue a Heat Flux Report on all boundaries and paste a screenshot of it here. In your picture one can see there is a gap between the two domains: is that gap modelled as solid?

I do not think it has anything to do with your velocity profiles but assess first without these proofiles.

[Rob]

I'd also avoid outflow. With two disconnected regions it's going to be interesting to see how they behave. Use pressure outlet.