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-   -   Too high temperature in the spray? (http://www.cfd-online.com/Forums/openfoam-solving/97396-too-high-temperature-spray.html)

chenhu February 16, 2012 06:31

Too high temperature in the spray?
 
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Hello everyone,

I am working on a solver (version 1.6.x) which combines the dieselFoam (spray) and engineFoam (premixed turbulent combustion). Since the fuel temperature is 320 K and ambient air temperature is 370 K, the region where there is fuel vapor should have lower temperature (due to evaporation, heat transfer), but I got higher temperature (e.g. 500 K) in that region.


Could anyone know the reason for this problem?

Thanks!

chenhu February 16, 2012 11:00

Problem solved :-)

The reason for the high temperature in the spray (fuel vapor zone) is due to the incorrect calculation of heatTransferSource. I am using the total enthalpy equatioin, but the heatTransferSource is calculated using sensible enthalpy (in version 1.6.x). This gives smaller sink term in the hEqn.H, and it gives higher temperature.

So be careful if you are updating your solvers or libs from old versions to 1.6.x (although it is quite old too) when dealing with H and Hs!

Chen


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