Transient simulation and optimization of planar heat source system based on finite element method

Traditional methods for measuring thermal properties often suffer from low efficiency and susceptibility to environmental interference. To address this, we present a three-dimensional full-scale simulation model based on the Transient Plane Source (TPS) method, employing a multiphysics-coupled finite element approach. The model is constructed in two stages: static simulation for determining the resistance and optimizing mesh refinement, and transient simulation coupling Joule heating with heat transfer. This framework reveals the current concentration toward the inner side of the double-helix probe due to the skin effect, leading to a non-uniform heat source distribution — a phenomenon rarely quantified in prior studies. Using specialty glass as a reference, the simulated and experimental temperature rise curves show excellent agreement with an error below 3%. The model is further extended to silica and PMMA, yielding similarly high consistency and thermal conductivity inversion errors within 3%. Additionally, a Python program is developed to automate thermal conductivity calculations and enable data visualization. These findings not only validate the proposed simulation strategy but also provide a theoretical foundation for optimizing TPS probe geometry, experimental parameters, and the development of next-generation high-precision thermal property measurement systems.