CFD Online Discussion Forums

CFD Online Discussion Forums (https://www.cfd-online.com/Forums/)
-   Fluent UDF and Scheme Programming (https://www.cfd-online.com/Forums/fluent-udf/)
-   -   Species volume fraction (https://www.cfd-online.com/Forums/fluent-udf/73861-species-volume-fraction.html)

sega March 18, 2010 11:54

Species volume fraction
 
Hello world.

How can I determine which volume fraction a species occupies in one cell?

sega

sega March 20, 2010 14:51

Come on guys.

This can't be so tought.

Allan Walsh March 22, 2010 11:18

Um, what do you mean by "which volume fraction"? For example, the bottom, right corner of the cell? I'm guessing you mean you want to convert the mass fraction to volume fraction.
This can be done using the cell density, molecular weight, and the molecular weight of the species of interest. I believe there is an example of this in the UDF manual under the macro for volume reaction rate.

sega March 22, 2010 11:37

Quote:

Originally Posted by Allan Walsh (Post 251137)
Um, what do you mean by "which volume fraction"? For example, the bottom, right corner of the cell? I'm guessing you mean you want to convert the mass fraction to volume fraction.
This can be done using the cell density, molecular weight, and the molecular weight of the species of interest. I believe there is an example of this in the UDF manual under the macro for volume reaction rate.

Yes you are guessing right: mass fraction / mole fraction to volume fraction would be nice.

There are two examples for the volumetric reaction rate in chapter 2.3.27.
None enlightens me how this should be possible.

Do you have an equation how this works?
I'm sure I can handle the programming part of it ...

arashoil November 27, 2011 11:17

udf
 
hi,

can i modelling asphaltene precipitation that exist in crude oil by uusing ceramic filter monolit by defult formolation in fluent?

i want to modelling separation of asphaltene from crude oil by 19-channel ceramic filter,but i think it is not define in FLUENT that precipitate asphaltene on surface of ceramic channel base on diffrences between pore size.

i must write UDF for this porpuse or not?

most of oil flow must pass through the membrane wall and most of asphaltene must form a gel-layer and precipitation on inner surface od channel.

please help me as soon as possible

thank you so much

hane April 16, 2014 02:02

Quote:

Originally Posted by sega (Post 250653)
Hello world.

How can I determine which volume fraction a species occupies in one cell?

sega

write C_VOF( , )


All times are GMT -4. The time now is 11:00.