TRANSIENT CONJUGATE HEAT TRANSFER IN A THICK-WALLED PIPE WITH DEVELOPING LAMINAR FLOW

Abstract

The transient behavior of the flow and temperature fields in a thick-walled pipe was analyzed by simultaneously solving for conduction in the pipe wall and for convection in the fluid stream. Two different transient situations were considered: the transient heat transfer in steady, developing pipe flow, and the simultaneous transient development of flow and heating in a pipe. In each case, a parametric study was done to understand the effects of ratio of watt thickness to inner diameter, Piclet number, ratio of wall to fluid thermal conductivities, and ratio of watt to fluid thermal diffusivities. All these parameters were found to significantly influence the duration of the transient as well as the distributions of Nusselt number, interfacial temperature, bulk temperature, and interfacial heat flux during the transient processes.