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-   -   Injection Files Troubles (http://www.cfd-online.com/Forums/fluent/48629-injection-files-troubles.html)

Rachel June 29, 2008 21:41

Injection Files Troubles
 
When the injection file provided by experiments is used, the error is given as the following, ,

Error: > (greater-than): invalid argument [2]: wrong type [not a number] Error Object: nan

I guess, it might result from my injection file. Actually, for 2D case, the injection file is as,

((X Y Z U V W diameter T mass-flow) name) ((0.003 0.0194690270 0 3.2116519170 0.7474598490 0 2.18264820E-05 307.12 103.4429119568600) injection-0:0) ... ((0.003 0.0194690270 0 3.2116519170 0.7474598490 0 2.18264820E-05 307.12 103.4429119568600) injection-0:n)

Is there something wrong with my file? BTW, mass flow rate should be provided in the injection file. Unfortunately, only mass flux was measured. In terms of 2-D case,

mass-flow rate = (mass flux)/(cell length)

Is it right? Any help is appreciated very much.

ndorma July 1, 2008 17:55

Re: Injection Files Troubles
 
i could be wrong but i thought that flux had units of kg/m^2-s and this would give: flow-rate = flux * area


Rachel July 1, 2008 17:59

Re: Injection Files Troubles
 
Thanks a lot, Ndorma. I have realized it. But, the area should be the cell area which the injection lies in, right?

ndorma July 1, 2008 18:07

Re: Injection Files Troubles
 
i never used injection files, but if you need the mass flow rate at each cell face on the inlet boundary thread then you could divide the total flow rate by the number of cell faces in that thread. it may sound like a i know what i am saying but i surely dont


Rachel July 1, 2008 18:18

Re: Injection Files Troubles
 
Actually, the mass flux is provided by experiments along a certain line. Unfortunately, it is required to define mass flow rate in the injection file. I agree with you in terms of dividing the total flow rate.

Anyway, thanks a lot, ndorma.

dnarmo July 1, 2008 18:21

Re: Injection Files Troubles
 
np


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