EXPERIMENTAL MEASUREMENT OF STEADY 3-D THERMAL GREEN'S FUNCTIONS

摘要

In many areas of applied mathematics, the Green's function is the solution to a field problem due to the application of a potential or a gradient of a potential at a point or line in space on the solution domain. In heat transfer, the 'thermal' Green's function (TGF) is the temperature field that would arise as a result of the application of a point source of heat within or on the surface of a medium. We have been exploring the possible use of the thermal Green's function as a new way of characterizing the convective heat transfer from the surface of a solid that is cooled by a flow. An experiment was designed to explore possible ways in which the thermal Green's function can be measured in the laboratory. A small heated spot was created on the wall of a flow channel to approximate a point source of heat. The resulting temperature field was measured by the use of thermochromic liquid crystal thermography, and was compared to an analytical solution derived from the 3-D thermal Green's function. This paper reports progress towards understanding the limitations in creating and digitally photographing the temperature field from a small heat source on the wall of a convective flow.