The shape factor for conductive heat flow in regular polygonal and circular cross-sections

Abstract

Different approximate methods have been used for the analysis of the conductive heat flow through cylinders with two or more contours of different forms. In this paper we present a very simple expression, based on conformal mapping and domain variational theory, for the shape factor of a coaxial system consisting of an N-regular polygon and a circle. The results, even for N = 3 and with very close boundaries is optimum when compared with the most sophisticated calculations available in the literature.