Bulk mean fluid temperature in internal flow
 

Hi, how to calculate the mean bulk fluid temperature in channel flow in FLUENT? I have a hot spot at a specific location (therefore temperature profile in the channel will be different at different locations) and want to estimate convective heat transfer coefficient and Nusselt number.

The definition of mean bulk fluid temperature is
int(rho*c_v*U*T)dA / m_dot*c_v

Should I use UDF? If so, can anybody share the code with me? I'm really a beginner in UDF, so have no idea how to start to code.

I appreciate your helps.
MS