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Marco September 19, 2008 06:34

lagrangian multiphase analysis
 
Hi !

I am using Star-CCM+ and I am doing lagrangian multiphase analysis for tracking grease droplet particles.

I am simulating a simple pipe with 1 inlet and 1 outlet, and the other boundaries are set to "rebound" condition, so all the particles will escape throw the outlet.

I want to calculate the quantity of particles leaving the domain, and I aspect that is the same that I inject, but it is not !!! I do a sum report of Incident mass flux on Outlet, and I multiply it for the outlet area to obtain the mass flow rate. The value that I obtain is 100 times higher than inlet value, how it is possible ? There is any other way to calculate the particle mass that leaves the domain ?

thanks in advance to everybody ...

Marco

Richard September 19, 2008 08:28

Re: lagrangian multiphase analysis
 
Incident mass flux is mass/area/time, so you should do a surface integral report of it to get mass/time. This is not the same as (area)*(sum report) unless all the faces have the same area.

Also make sure you are injecting what you think you are, e.g. is the mass flow rate specified per injection point or total.

lelia September 20, 2008 11:41

Re: lagrangian multiphase analysis
 
Hi, you can find anything about your particles (almost :) ) if you select them all and import their characteristics into a output folder. after u select the particles and plot them on the screen the commands are: ofile,part.out dlist,dset dlist,dset,,,other ofile,screen close,part.out

hope it helps! regards, lelia


Marco September 22, 2008 09:43

Re: lagrangian multiphase analysis
 
Thank you Richard, now it works with your advise. I don't know why I used the sum function ....

Cheers

Marco


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