CFD Online Discussion Forums (https://www.cfd-online.com/Forums/)
-   FLUENT (https://www.cfd-online.com/Forums/fluent/)
-   -   Calculating volume of Phase (https://www.cfd-online.com/Forums/fluent/47496-calculating-volume-phase.html)

 Pavan March 3, 2008 12:50

Calculating volume of Phase

Hi All, Assume that I have a problem with say 3 immiscible liquids with different densities such that liquid 1 is above liquid 2 which in turn is above liquid 3 in a cylindrical domain. The domain has a drain at the bottom from where the liquid (liq 3 to begin with) starts to flow out. After certain amount of flow time, if I were to calculate the mass/vol of say liquid 3 remaining in the domain, how would I calculate it?

I tried to use the report volume integral menu by calculating volume integral of field vairable -- Phases -- volume fraction -- liquid 3. This gives a volume in m3 which I then multiply with the density of liq 3 to get the mass. However, I am not sure this is the correct way to do it because I observed that when I use this procedure to calculate the volume of say liq 2 which is just floating down, the value of the volume changes over the flow time. This should not be the case because liq 2 hasn't been drained yet. It is a const density liq just moving down. I infer then that the vol integral is only providing a sum of volumes of each cell that holds that liq. I am a little confused about how I can calculate the volume that I want. Any ideas? Thanks.

Pavs

 Aidan March 3, 2008 18:49

Re: Calculating volume of Phase

setup a custom field function of Volume Fraction*Phase Density for each of your three phases. Then do a volume integral of the field function. This should give you the mass of each phase in the domain.

 Pavan March 5, 2008 11:04

Re: Calculating volume of Phase

Thanks Aidan. It was pretty much what I was doing. I was concerned about the difference I was seeing over flow time. But the error was less than 1.5% That still should not exist but I guess it could be numerical error or something. I guess I won't worry about it.

 All times are GMT -4. The time now is 10:36.