Heat transfer characteristics of a duct flow with a backward-facing step - Effects of Reynolds number and channel aspect ratio

摘要

Distributions of local heat transfer coefficients have been measured by making use of a thermo sensitive liquid crystal sheet in order to grasp the heat transfer characteristics on the bottom wall downstream of a backward-facing step flow in a duct for various Reynolds number and channel aspect ratio cases. The maximum heat transfer appears near the side wall for the channel aspect ratios from 8 to 24, while more unifom heat transfer spanwisely generates for the aspect ratios of 4 and 32 in every Reynolds number case. As aspect ratio becomes larger, the value of the maximum Nusselt number increases and the spanwise location of it moves closer to the side walls in every Reynolds number case.