Numerical Analysis on Laminar Heat Transfer in the Thermal Entrance Regions of Concentric Annuli with Axially Moving Cores

摘要

Fundamental solutions of the second kind boundary condition were obtained numerically by a finite difference method for the thermal-entrance-region laminar heat transfer in a concentric annulus with an axially moving core. Heating conditions of the second kind are (1) on one wall, constant axial as well as peripheral wall heat flux is specified and the other is insulated; (2) both walls are heated independently. The effects of the relative velocity of the core and the radius ratio on the temperature, Nusselt numbers and thermal entrance lengths have been investigated. The influence coefficients are presented graphically, which are necessary to calculate the Nusselt number at each surface for the case of both walls heated.