Tek-Tips is the largest IT community on the Internet today!
Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!
-
Congratulations cowski on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!
Thermal Resistance of a Surface Area
- Thread starter Jakwani
- Start date
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?Heat transfer to the ambient air is through natural convection. You could read the articles and the procedure to calculate natural convection coefficient for your application.
You could refer to any heat transfer calculation book or Perry's handbook.
You could refer to any heat transfer calculation book or Perry's handbook.
There are two modes of heat transfer involved.1)thermal radiation, 2)convection. One dimensional analysis would yield:
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)
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)
- Status
Similar threads
- Locked
- Question
- Locked
- Question