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diffusion Term for add. Variable

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Old   July 14, 2011, 05:13
Default diffusion Term for add. Variable
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Hello,
How can i get ride of the diffusion terms in the transport equation for additional variable. I am trying to transport number density like entity but in the theory there are only Source terms on the right hand side of the equation.

Thx Jessica
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Old   July 14, 2011, 07:59
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I do not understand what you mean.

Do you want to have a transport equation with no diffusion? Just select the transport equation option for the additional variable in this case.
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Old   July 14, 2011, 10:14
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i am using this transport equation but there exist the diffusion term.
In fact i want to implement an equation like this for the Droplet number Density

(dN/dt)+(dUi.N)/(dxi)=Source

that means without effect of the turbulent diffusion..
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Old   July 14, 2011, 19:31
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So can't you just use a convection only additional variable?
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Old   July 15, 2011, 03:23
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Yes Convective time dependent variable but how?
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Old   July 15, 2011, 06:24
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Add an additional variable, and set it to a transport/convection equation.
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Old   July 15, 2011, 07:11
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that is what that i did but there exist these diffusion terms in the equation of.
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Old   July 16, 2011, 06:52
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What diffusion terms? There are not diffusion terms in the convection additional variables. And even if there are, why not just set the diffusion coefficients to zero?
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Old   July 16, 2011, 09:48
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There are Diffusion Terms in the Transport equation for add. Variabel. And please tell me how to set the Coefficient to zero.
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Old   July 16, 2011, 09:51
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including both laminar and turbulent diffusion... in the theory of the transport equation for the number density of droplet, bubbles and other particles, no diffusion terms and included..
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