Thermal Resistance of a Surface Area
Thermal Resistance of a Surface Area
(OP)
I have a piece of metal (2"x4") that I am using as a heat sink (amplifier is mounted on heat sink). I would like to calculate Thermal resistance (C/W ) from sink to ambient. Can someone help me with this?
Thanks a lot.
Thanks a lot.





RE: Thermal Resistance of a Surface Area
You could refer to any heat transfer calculation book or Perry's handbook.
RE: Thermal Resistance of a Surface Area
q_total = (T_sink - T_air)/R_total
where R_total= 1/(hA) + 1/(h_rad *A)
where h = convective heat transfer coefficient and is a function of the fluid properties, temperature difference and the orientation of your sink. Must be determined using correlations from any heat transfer book
A: is the heat transfer area
h_rad: normalized radiant heat transfer coefficient
h_rad = (surface emmisivity * Stefan Boltzman constant)*(T_sink^2 + T_air^2)*(T_sink + T_air)