COUPLED ANALYSIS OF FLUID-TO-SOLID HEAT TRANSFER IN THICK-WALLED SHORT TUBES WITH UNIFORMLY IMPOSED TEMPERATURE

Abstract

Under the assumption of temperature-invariant properties, this paper explores the influence of a finite heated length on the heat transfer characteristics of laminar flows through thick-watted circular tubes. This conjugate problem, having a uniform temperature applied at the outer surface of the tube, is governed by four dimensionless groups: the length of the heated region, the Peclet number, the solid-fluid conductivity ratio, and the radii ratio of the tube wall. Using a finite difference procedure with control volume discretization, it was found that the inclusion of the two-dimensional conduction model at the wall tends to distort the distributions of the mean bulk temperature of the fluid and the solid-fluid interface temperature at low Peclet number flows. As a result, heat transfer rates between the tube watt and the fluid stream are significantly altered. In addition, it was found that for situations in which Pe > 200, the conjugate nature of the problem relying on one-dimensional wall conductio...