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-   -   Simulation of Multiphase Heat Exchanger (https://www.cfd-online.com/Forums/cfx/103023-simulation-multiphase-heat-exchanger.html)

 faisal_ahmed92 June 8, 2012 13:54

Simulation of Multiphase Heat Exchanger

Hello all, I've been using Cfx 13 to simulate a heat exchanger simulation, with water flowing through outer chamber taking heat from inner coil, through which acetone flows. Due to heat given to water acetone condenses
My approach to solving:
Define two separate domains, water and acetone zone, and then in the domain interface define a heat exchange with copper of 1mm thickness. Problem is my solver keeps crashing after 3 or 4 iterations with
Floating Point Error : Overflow,
The one time I got a complete run, the CFD post doesn't show any streamlines for the coil domain. Please help, Ive been at it for weeks now!!
http://img140.imageshack.us/img140/5153/modelg.png

 faisal_ahmed92 June 10, 2012 10:12

Anybody PLEASSE!! Ive been stuck on this a very long time!!

 ghorrocks June 11, 2012 20:14

 faisal_ahmed92 June 12, 2012 03:06

Just wanted to say that you are legend over here!!. Many thanks, I tried using those steps and got a solution, but the problem is the solver doesn't solve for the inner(coil) domain at all. I looked up the condensation tutorial, but that has a mixed gas phase and a liquid phase, whereas i am looking for a gas and a liquid phase in one single domain(coil). Any thoughts?

 ghorrocks June 12, 2012 19:44

I would do some development work with the inner domain only. Run that as a model by itself and see what settings it likes to converge. Then combine that with the full simulation.

 faisal_ahmed92 June 13, 2012 03:22

I tried doing that for single phase fluids and it worked WITH the outer domain as well, but when I switch to a condensation model (Acetone vapor continous phase and acetone liquid dispersed fluid), the solver just doesnt solve for the inner domain

 ghorrocks June 13, 2012 07:33

Condensation models are tricky multiphase models - so replace the outer domain with a constant temperature wall and work on getting condensation working in that simpler case before coupling it together.

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