Abstract
Heat transfer in noncircular passages recently has received increased attention in connection with various engineering applications, especially with nuclear-reactor technology. The present paper presents the results of calculations for heat transfer connected with steady laminar flow through ducts whose cross sections have the shape of circular sectors. Hydraulically and thermally developed flow is assumed. The temperature field, peripheral distribution of inner-duct surface temperature and of heat flux, as well as heat-transfer coefficients and friction factors, are presented for two boundary conditions: Peripherally constant heat flux and peripherally constant surface temperature, both with longitudinally constant heat flux. It is found that even average heat-transfer coefficients may be different by an order of magnitude for these two conditions. For this reason, it is pointed out that solutions for a class of boundary conditions can be obtained by linear superposition of the results obtained for the two conditions mentioned.
