Author Topic: How to calculate heat transfer rate within UDF?  (Read 1987 times)

Offline pico

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How to calculate heat transfer rate within UDF?
« on: February 12, 2012, 12:24:19 PM »
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Hi,

Within a FLUENT UDF, how can I calculate the total heat transfer rate (radiative + convective), radiation heat transfer rate, or the absorbed radiation flux on surfaces?


Offline william

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Re: How to calculate heat transfer rate within UDF?
« Reply #1 on: February 12, 2012, 12:26:21 PM »
Use the following macros

1. BOUNDARY_HEAT_FLUX(f,tf) to obtain the total heat transfer rate
2. BOUNDARY_RAD_HEAT_FLUX(f,tf) to obtain the radiation heat transfer rate
3. F_DO_QA(f,t,nb) to obtain the absorbed radiation flux when using the DO model

Note that "FLUX" in the macro is a mis-nomer and it gives the total heat transfer rates in watts and NOT the heat flux in watts/m2.

C_ABS_COEFF(c,t) gives you the absorption coefficcient at a cell. This is not the same as the absorbed radiaiton flux at the wall.