Thin Disk On A Convectively Cooled Plate—Application To Heat Flux Measurement Errors

Abstract

An analysis is made of the steady-state thermal processes associated with a thin disk affixed to a convectively cooled solid plate. The disk represents a thermopile heat flux gauge. In the first part of the paper, the heat conduction problem of the plate is solved for the simplified condition where the heat flow through the disk is axially one-dimensional. It was found that the local divergence of the heat flux field within the plate owing to the presence of the disk may result in a gauge reading that underestimates the heat transfer rate. Also, a sizeable local plate temperature augmentation can occur. Furthermore, the analysis yields dimensional estimates of the region where the temperature and heat flux fields within the plate are significantly altered by the presence of the disk. An adjunct to the foregoing analysis develops a one-dimensional conduction factor which is useful in determining when the heat flow through the disk can be considered to be axially one-dimensional.