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-   -   CFX - Evaporation problem (http://www.cfd-online.com/Forums/cfx/67530-cfx-evaporation-problem.html)

AlessandroD August 18, 2009 06:03

CFX - Evaporation problem
 
i need to implement Liquid Evaporation Model on CFX11.1, but when i activate it with particle tracking + heat transfer + ETAB(secondary breakup) the simulation fail, with FATAL OVERFLOW ERROR. I'm using a structured mesh in a return channel+ diffuser of a centrifugal compressor, and i making a steady state simulation. The runnings fails, only with evaporation model, and the error is in some track of particle that arise temperature value about 2000k and -2000K, in a domain which the temperature are:
gas temp total = 350,25 k
water injected temp tot = 323 k
i don't understand why the CFX does this problem. In the 100 discretization tracks that i have used, only in some spot in 3 or 4 tracks the temperature Fail, and in conseguence of it, fail Mach number and the simulation.
The situation goes better if i used a restitution coefficient =0, but this is true only in a struct mesh (4,6Milion), this behaviour is different in a coarse mesh, in this last case, the evaporation model fail with a zero restitution coefficient at wall boundary, too. i can't understand the evaporation model in CFX, it work well or someone had in the past similar problems?

I hope in some answer, someone in the world have to understand this problem!! thanks a lot!


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