Hi,

I have a problem when I would like to calculate the averaged mass fraction of a mixture at thought the outlet.

The case is mixing two fluids in a large tank. The fluid is extracted using an outlet with a pump and then injected at another possition in the tank.

How can I calculate the averaged mass fraction thought the outlet area and then use this to specify the mass fraction at the inlet ???

Thanks.

Regards

Jens

Hi Jens,

Assuming a multicomponent fluid called "Fluid", a component named "componentA", and you are measuring flow at a boundary named "Outlet", the following expression will do the trick:

massFlowAve(Fluid.componentA.mf)@Outlet

Regards, Robin

In CFX 4, you can write a output file using Command file:
:>PATCH DATA PATCH NAME 'OUTLET' FILE NAME 'OUTLETAVERAGE.DAT' AVERAGE SPEICES1 EACH TIME STEP

Hi

I am having some problem setting the mass fraction using the method you describe.

I keep getting error:

"and then error found at item: massFlowAve

unrecognised name

Error processing expression: Mass Fraction = scAn error has occurred in cfx5solve: "

I define the massfraction in the cel file as:

sc = massFlowAve(Mixture.SodiumChlorite.mf)@outlettop

Can you give me any hints on what the problem is ???

Thanks

Regards

Jens