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-   -   How to create a pollution dispersion model? (http://www.cfd-online.com/Forums/cd-adapco/56778-how-create-pollution-dispersion-model.html)

Diwanshu August 28, 2008 21:50

How to create a pollution dispersion model?
 
Hi everybody, Currently, I'm doing a project on pollutionn dispersion. I have created a geometric model and also solved the model with a reasonable wind speed at inlet. The solver is the k-e model, steady, coupled flow. What I'd like to know is that: since i have the solved flow field, will i be able to predict the dispesion of pollution by having a pollutant source anywhere i want within the model? Or do i have to start from the beginning having a pollutant source and the inlet velocity; and solve it again? Thanks in advance


Pauli August 29, 2008 10:48

Re: How to create a pollution dispersion model?
 
If you want concentration predictions, you'll have to add a source (passive scalar) and solve again. If you just want to see where dispersion is likely, you could do a particle track post processing exercise.

Isn't the coupled flow solver for high speed (significant compressibility) flow?

Diwanshu August 29, 2008 15:19

Re: How to create a pollution dispersion model?
 
Thanks for your response, Pauli. I initially tried with the segregated flow and the solution did not converge. later, the solution converged when the solver was changed to coupled.

The Coupled Flow model solves the conservation equations for mass and momentum simultaneously using a time- (or pseudo-time-) marching approach. The preconditioned form of the governing equations used by the Coupled Flow model makes it suitable for solving incompressible and isothermal flows.

One advantage of this formulation is its robustness for solving flows with dominant source terms, such as rotation. Another advantage of the coupled solver is that CPU time scales linearly with cell count; in other words, the convergence rate does not deteriorate as the mesh is refined.


Diwanshu September 2, 2008 00:33

Re: How to create a pollution dispersion model?
 
I added the passive scalar and solved the model. the solution converged. Now, I want to add the location of the source. I don't see any option where i can specify the co-ordinate of the passive scalar source. Or do i have to create a region before solving the model.

Does anybody has any idea on how to do this?

Thanks in advance!!!

sillymonkey September 3, 2008 11:49

Re: How to create a pollution dispersion model?
 
"Or do i have to create a region before solving the model"

yes


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