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Spray Burner results vary with nozzle orientation. #15

Closed GoogleCodeExporter closed 9 years ago

GoogleCodeExporter commented 9 years ago 
FDS5 RC1 
I have been running the varification samples and compairing the results to 
the varification guide.   In running the spray_burner sample as given, I 
get the expected results.  However, when I change the nozzle orientation 
to horizontal, the heat release rate never reaches 2MW.  It peaks out at 
around 1.75MW (average).  With the nozzles pointed up, instead of down, 
the HRR peakes out at around around 1.85MW (average).  When the HRR is 
graphed, the shape of the curve is the same as illustrated in the 
documentation, just that the upper platue never reaches 2MW in these two 
scenarios.

Is this an issue with FDS; or my lack of understanding of 3 dimensional 
spay fires?

Regards
MK

Original issue reported on code.google.com by kmil...@lasvegasnevada.gov on 10 May 2007 at 1:54

GoogleCodeExporter commented 9 years ago 
With the nozzles pointed downward all the fuel collects in the fuel pan and can 
evaporate.  When you point the nozzles upward or to the side, fuel droplets can 
leave the domain before they evaporate.  Droplets that leave the domain without 
evaporating do not contribute their full mass to the heat release rate.

Original comment by drjfloyd on 10 May 2007 at 2:31