CFD Online Discussion Forums - HEAT-TRANSFER & EXCHANGE HEAT MODEL Problems

HI, My name is Jordi and I'm from Spain. Well, I have a problem with FLUENT. I am trying to simulate a radiator with Fluent, well is more a heat-exchanger than a radiator, it's is a motorcycle radiator exactly. It's like n-vertical-tubs, where the water go inside them. And the water enter the raditior from the top and go out from the bottom. None of the tubs are conected in the radiator body. I mean There is a one tub in the top, then it's subdivided in n-tub and the in the bottom the n-tubs are connected in only one tub.

For the mopment I only drew a tub and a tunnel in GAMBIT because I could use the symetry in this case. I simiulate the air through the tunnel and the water through the tub. Then I put it in T-GRID and then in FLUENT. I am trying to get a simulation of a exchange heat between them. At the moment I only get a exchange heat in that direction:

WATER (350K) -> WALL (Thickness=0.001m) -> AIR (298K)

The water allways is 350K.

The air, if the velocity is 0m/s, there is heat-exchange. And if the velocity is 20m/s i can't see or there isn't a heat-exchange.

What I want is the reverse process, I mean:

AIR (298K) -> WALL (Thickness=0.001m) -> WATER (350K)

Try to get the Water Temperature in the outlet about 310K. ANd can see the temperature change through the tub.

And the Air Temperature arround the tub about 300-310 K, more or less.

My problem is: In first place, I don't know exactly the meaning of the Thermal Conditions in the WALL Pannel. I think I could need the CONVECTION in the Thermal COndition, but I don't know how to show up that. In second place, I woukld like if somebody could help me with that. If somebody don't get what I said, please let me know and I will explain my case more carefully. And finally, congratulations for the web and thanks to everybody for help somebody like me who don't know so much about FLENT. Thanks a lot,

BESTS!

JORDI.