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-   -   Granular Temperature? (http://www.cfd-online.com/Forums/fluent/77919-granular-temperature.html)

g0dmaphia July 7, 2010 12:49

Granular Temperature?
 
Hi i have a problem with a 3d simulation of an high pressurized bottle (70 bar) discharging a powder into an engine bay (modelled as a big cilynder). The model i use is a Mixture model with Nitrogen Ideal and this powder as 2nd phase (patched at the end of the bottle, near the exit nosel)... the problem is that when i start the simulation i always get high temperatures and the solution diverges immediatly.

I think it is related with the granular temperature of the powder, cause i donīt know what is it and what should be a good value to set...

I think that the mesh is good, it is HEXA with determinants all over 0.3 and angles over 27°...

Thanks in advance :)

Goldsstean July 8, 2010 10:24

Granular Temperature is not temperature. It is the kinetic energy posses by the particle before collussion:eek:

g0dmaphia July 8, 2010 10:40

yes i know, but i donīt know what is a good value for my case... i thought that setting a strange value could screw up my simulation and let fluent going nuts (high temp, high viscosity ratios and so on)..

Default value is 0.0001 but i donīt know if it is good or not for my simulation, do you have any experience with granular flow? My particles are really small, something like 5 micrometers...

Thanks :)


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