Radiation Heat Transfer Between Two Surfaces. Microscopic section of this contact area the modes of heat transfer across the interface would be. Note from eq.
Conduction is the transfer of energy from one molecule to another by direct contact. Consider two flat infinite planes surface a and surface b both emitting radiation toward one another. 1352 that if j i j j net heat transfer is from surface i to surface j.
Surface a will emit radiation according to the stefan boltzman law as.
Concentric cylinders or concentric spheres. The blackbodies are maintained at constant temperatures by internal heaters. The fraction of radiation energy leaving a surface a 1 that reaches another surface a 2 is called the radiation shape factor f 12 or f 21 in the reverse case. Radiation can occur between two bodies separated by a medium colder than both.