A new and simpler formulation for radiative angle factors

E. M. Sparrow

Research output: Contribution to journalArticlepeer-review

103 Scopus citations


A new representation for diffuse angle factors has been derived which replaces the usual area integrals by more tractable contour (i.e., line) integrals. The new formulation generally simplifies analytical calculation of angle factors. The advantages of the new representation are associated with the reduced order of the integrals (i.e., double reduced to single, quadruple reduced to double) which must be evaluated to calculate the angle factor. An additional benefit of the new representation is that integrals of simpler form are encountered than in the present representation. For the numerical evaluation of angle factors, the reduction in the order of the integrals should have great practical utility. In the case of energy exchange between an infinitesimal element and a finite area, a superposition theorem has been derived which permits results for certain basic surfaces to be linearly combined to yield angle factors for surfaces at other orientations. Several illustrations of the application of the new formulation are presented.

Original languageEnglish (US)
Pages (from-to)81-87
Number of pages7
JournalJournal of Heat Transfer
Issue number2
StatePublished - Jan 1 1963


Dive into the research topics of 'A new and simpler formulation for radiative angle factors'. Together they form a unique fingerprint.

Cite this