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ak6g08 May 26, 2009 15:21

Charge transport UDF
Hello everybody,

I would like to write a UDF which calculates the value of charge, Q, and then another UDF which calculates the value of Electric field, E...I have found an example in the fluent manual which does a radiation calculation using a transport equation, which is useful, however, I need to use the values of Q and E in a source term (which I must also add) appearing in the momentum equation (source=Q x E)...

can anyone point me to an example which writes a UDF to calculate a scalar and then uses the value returned by that transport equation within a source term appearing in the momentum equation??

Also, the scalar transport equation for space charge has a diffusion, convective and unsteady term as with the generic version but also has an ionic drift term...which is sort of a convective term only instead of velocity its (kxE) where k is mobility and E is electric field...can I add a whole other term in the transport equation? Is that possible?

Thanks a lot

johnwinter June 27, 2011 04:21

Hi Akour,

Did you successful in writing udf for charge density?. I am planning to write UDF for negative ion and charge density. Could please share your experince.

I am having trouble linearizing source term for charge desnity equation. I am getting negative values in charge which is unrealistic.

Thanks in advance

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