Heat Transfer by Radiation

Written by Jerry Ratzlaff on . Posted in Thermodynamics

conduction convection radiantHeat transfer by radiation, abbreviated as \(Q_r\) or \(\phi\) (Greek symbol phi), also called heat radiation or radiation heat transfer, is one of four types of heat transfer: conduction, convection, mixing and radiation.  Radiation is the flow of energy through electromagnetic waves such as infrared, light, microwaves, etc.

Heat Transfer by Radiation formula

\(\large{ Q_r =  \sigma \; A  \left(  T^4 - T_e^4  \right)    }\)

Where:

\(\large{ Q_r }\) = heat radiation

\(\large{ A }\) = area of radiating

\(\large{ \sigma }\)  (Greek symbol sigma) = Stefan-Boltzmann constant

\(\large{ T }\) = temperature of object emitting

\(\large{ T_e }\) = temperature of environment

 

Tags: Equations for Heat Transfer Equations for Temperature