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-   -   mole concentration of species (kmole/m3) (http://www.cfd-online.com/Forums/fluent/31931-mole-concentration-species-kmole-m3.html)

neihad@hotmail.com August 4, 2003 00:57

mole concentration of species (kmole/m3)
 
Can anyone tell me how the mole concentration of species (kmole/m3) is calculated in Fluent?

Why kmole is used not mole! In real life the concentration of pollutants are not high e.g. CO concentration in a car park should be less then 30 mg/m3).

Have any one validated the concentration results against measurement data?

Thanks for your time

Cathy August 4, 2003 06:04

Re: mole concentration of species (kmole/m3)
 
Hi Neihad, Fluent converts inside, and yes its true that its kmole/m3.

Because in MKS system, unit of pollutants is kmole and volume is m3.

Cathy

Andrew Garrard August 4, 2003 11:09

Re: mole concentration of species (kmole/m3)
 
I have posted about the subject earlier. It is true that fluent uses kmol/m3, which can be irritating. I have chosen to model concentration with a UDS and standard mass flow flux function. In this case you can use any units you care for.

Ivan August 5, 2003 05:41

Re: mole concentration of species (kmole/m3)
 
which version of the FLUENT you are using it??

i was been told that the calculation for the mole conecentration in Flunet V6.0 got some problems.... corretced in Fluent V6.1.18

take care

neihad@hotmail.com August 5, 2003 23:48

Re: mole concentration of species (kmole/m3)
 
Thanks Cathy, Andrew and Ivan,

I am using Fluent 6.1.18.

I think it will good to know how fluent is predicting the mole concentration at the pollutant source from the boundary conditions (e.g. mass fraction and inlet velocity). Therefore, we could compare our calculations and measurements with fluent methodology.

Regards

Greg Perkins August 6, 2003 01:55

Re: mole concentration of species (kmole/m3)
 
Guys whats the hangup with units?????

You can always convert these from one to the other with little effort. If you want to see it differently on your screen I suggest you write a custom field function to multiply your results appropriately.

If you want mass concentration to be reported instead of molar concentration just define a custom field fucntion as:

C_mass_i = rho*Yi

It will take less time to define than the time I've spent writing this email!

Greg


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