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problem with dispersed solid model and exp

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Old   October 3, 2016, 23:09
Question problem with dispersed solid model and exp
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hi
I'm modeling a tank that contain water and some solid particles. I'm using dispersed solid model to simulate solid particles. i want to record the volume fraction or mass concentration of particles at outlet. so i used the following exp:

ave(phase1.vf )@outlet

after some time...the tank is empty of solid particles but the exp give some bad result and it shows that solids are crossing the outlet but there is no solid in tank (
I did simulation with very qualified mesh but it happened again.i used dp but not helped...

can anyboidy help me whats wrong with this expression ?
i think the exp is wrong...please give me some ideas.

thanks
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Old   October 4, 2016, 04:51
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Glenn Horrocks
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Note the averaging function you used is just an arithmetic average of all the faces, regardless of size. You probably want to use areaAve() instead so you get an area weighted average.

But I cannot help you with your actual question at the moment. It sounds like a setup problem.
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Old   October 6, 2016, 11:23
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Quote:
Originally Posted by ghorrocks View Post
Note the averaging function you used is just an arithmetic average of all the faces, regardless of size. You probably want to use areaAve() instead so you get an area weighted average.

But I cannot help you with your actual question at the moment. It sounds like a setup problem.

Hi ghorrocks. thank you
i also used areaAve() and the results were same..now I use massflowAve() and i'm waiting for the results...

some information of simulation:
particle diameter : 30 micron
particle density :1900 kg m^-3
using buoyancy
turbulence model: k-e RNG (Homo)
isothermal
drag coef: 0.44 (default)
BC: 1 inlet-1 outlet-2 symmetric-walls..

and something that make me confused in results : for the walls..the contour show a 0.5 volume fraction for solid just at one point on wall (after the whole particle left the tank) ..I used very very refined mesh with inflation...max of yplus is 3
...
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Old   October 9, 2016, 07:04
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Is this a Eularian or Lagrangian model?

Please shows some images of what you are modelling and the results you are getting. Also show why it is wrong, and what you expect to get.
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