A step forward on the network method for radiation heat transfer analysis in enclosures

Abstract

It is proposed an approach of the network method for radiation in enclosures that expresses radiosities and irradiations as functions of the blackbody emissive powers and of the radiation fluxes entering the enclosure through its partially transparent walls. These results are used to express the radiation heat flow exchanged between two surfaces and the net radiation heat flux leaving each of the enclosure’s surfaces as depending on these true driving forces for radiation heat transfer. This reduces the problem to its essential, as these are the true driving forces for the radiation heat transfer. Net radiation heat fluxes leaving each of the enclosure’s surfaces form an equations’ system from which are evaluated the relevant radiation heat transfer parameters for each surface. Proposed approach is based on elementary matrices operations, the main attention being dedicated to the problem setting and leaving the (just essential) calculations to the calculator or to the computer. It is introduced for enclosures with all opaque walls and illustrated for one example, and then extended to enclosures with partially transparent walls. Proposed simplifying and unifying approach is relevant not only for radiation heat transfer analysis and calculations, but also for pedagogical purposes, retaining attention on the essential of the radiation heat transfer problem formulation, setting aside intermediate/auxiliary variables calculations that are usually aversive, fastidious, distractive and prone to errors.