SIMULATION OF THE HOT DISK SENSOR: TEMPERATURE AND ELECTRIC CURRENT DISTRIBUTION

Paper in proceedings, 2017

The Hot Disk method, also known as the transient plane source (TPS) technique, is an experimental approach for determining the thermal transport properties of materials. The core of the method is the Hot Disk sensor, an electrically conducting metallic foil (typically nickel), shaped as a double spiral, clad with a protective polymer film or mica. The double spiral serves simultaneously as heat source and temperature probe. The mean temperature increase of the TPS- sensor has been formulated from various analytical approaches such as: the concentric ring sources model, the thermal quadrupoles formalism, and concentric circular strips structure approach. However, full numerical simulation of the sensor has not been addressed so far. Here we develop 3D model of a Hot Disk sensor. The simulation provides information such as temperature and current distribution along each spiral which is not accessible from the experiment. Modeling feature, Joule heating coupled with heat transfer in solids of COMSOL Multiphysics software is used to simulate the sensor. The temperature and current distributions along the nickel wire is obtained. This can potentially be used in further optimizing geometry and estimating better parameters.