CFD Online Discussion Forums

CFD Online Discussion Forums (
-   Phoenics (
-   -   mass flux (

billow August 2, 2005 05:48

mass flux

There is a OUTLET plate in my simulation to represent the natural air.In my result file I get its total flux by: ------------------------------------------------- Nett source of R1 at patch named: OB1 (OUT) =-1.684879E-01 ------------------------------------------------- How can i get the mass flux in and mass flux out?

mick August 2, 2005 07:11

Re: mass flux
You can't necessarily from what is directly printed in the result file.

What you need to know is the value of the normal velocities at the outlet. If you know these you can make an educated guess. Some people might make ground coding (compilable version only), others might experiment with INFORM.

Others just examine the viewer and make an educated guess.

However one simple way is to set up the output to print out values for the cells covered by the outlet. Then you will get a print out of the normal velocities at the cells which cover the outlet.

To set this up goto OUTPUT->FIELD PRINTOUT-> SETTINGS and change IXPRF, IXPRL and NXPRIN etc IXPRF gives the first cell for printout IXPRL gives the last cell and NXPRIN gives the frequency, set NXPRIN=1 to cover all the cells.

If you want to make a really accurate estimate you might want to store den1 and aeast or anorth or ahigh depending what side of the domain the outlet is on.

These will give similar output to the result file for cell face area and density and hence flow will be den1 * vel * area for each outlet cell in question.

mick August 2, 2005 10:39

Re: mass flux
also see previous posting.

khaled ghreep May 3, 2006 09:31

Re: mass flux
Dear Sir. I have a simple problem but i cann't solved it the problem is (1) air contains a number of particle of 8000 per cubic centimeter in a vessel (2) the air flow through a tube with 2 liter per min for 10 min. (3) the particles were collected in a filter (4) the collected particles on the filter were counted and it found 200 particle (5) the filter is a circular 24 mm in radius I would like to calculate the ratio between the collected particle on the filter and the in the vessel I wait u reply as soon as possible Khaled Ghraib

All times are GMT -4. The time now is 22:56.