Heat conduction through heat exchanger tubes of noncircular cross section

Conduction through shaped tubes with circular inner surface and hydrodynamically shaped outer surface has been analyzed by two different techniques. A two-dimensional analysis has been made by a semianalytical technique using boundary collocation at the outer periphery. A one-dimensional approximate technique called sector method shows a closed agreement with the two-dimensional analysis. The present work gives an improvement on the analysis of Li et al. (2004, Heat Transfer Enhancement Using Shaped Polymer Tubes: Fin Analysis, ASME J. Heat Transfer, 126, pp. 211-218) who solved the same problem using a one-dimensional approximation following the methodology of fin analysis. Both the present methods relax some of the approximations taken by Li et al. Further the suggested one-dimensional sector method is simple and requires limited computational effort.