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-   -   time dependent B.C (http://www.cfd-online.com/Forums/fluent/32492-time-dependent-b-c.html)

co2 November 11, 2003 12:25

time dependent B.C
 
Dear Fluent users,

Please help me out with the following question -

In my model, I have a wall with heat flux B.C. Now I need to change the heat flux value every minute - thus making it a time varying B.C. But I have no idea as to how to do it - I know it has something to do with profile writing etc. But I have not found a fluent tutorial that can tell me how to do it - The help files discuss this topic but I have not been able to really do anything with it. Can someone provide me some example of the profile file, a tutorial etc, may be some other website..

Thank you and looking forward to a helpful reply from someone.

Alamgir November 18, 2003 20:59

Re: time dependent B.C
 
it should be like velocity profile UDF. only u need to replace velocity with heat flux, (before proceding just get information what fluent macro is for heat flux). then call udf whr u put the value of heat flux.

if it is not enough just write to me, I may help u in this regard.

Alamgir

Alamgir November 18, 2003 21:01

Re: time dependent B.C
 
It should be like usteady velocity profile UDF

co2 November 26, 2003 15:55

Re: time dependent B.C
 
Alamgir,

thanks for your note. i was able to change the temperature of the wall using a function definition just the way they had shown in manual for transient velocity. but how to do the same with heat flux.

I actually have a formula for calculation of this heat flux and it depends on the revolution of sun around the object. the formula also requires some other complicated angles etc. let us say i do these calculations seperately in a excel spreadsheet and get the heat flux values for each minute of different walls. how do i feed these calculated values to the udf for heat flux of a particular wall?


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