Steady State Thermal Modeling and Heat Flux Analysis of Zinc–Calcium–Aluminosilicate (ZCAS) Glass Using COMSOL Multiphysics

A three-dimensional steady-state thermal analysis of zinc–calcium–aluminosilicate (ZCAS) glass was performed using the finite element method implemented in COMSOL Multiphysics® version 6.2. The Heat Transfer in Solids interface was employed to solve the steady-state heat conduction equation under mixed boundary conditions, consisting of two isothermal surfaces and thermally insulated remaining boundaries. The ZCAS glass was modelled as a homogeneous and isotropic solid with density 2500 kg·m⁻³, thermal conductivity 1.20 W·m⁻¹·K⁻¹, and specific heat capacity 750 J·kg⁻¹·K⁻¹. A tetrahedral mesh comprising 42,857 elements and 85,742 nodes was used. The numerical results show a smooth and monotonic temperature distribution with a maximum temperature difference of 17.2 K across the domain. Conductive heat flux vectors align with the primary temperature gradient, with a peak magnitude of approximately 860 W·m⁻², confirming strict compliance with Fourier’s law. A three-dimensional cut-line temperature profile exhibits a linear variation consistent with the analytical one-dimensional steady-state solution, yielding relative errors below 2.5%. Surface integration of the normal total energy flux gives 103.8 W and +103.8 W at the inlet and outlet boundaries, respectively, corresponding to an energy imbalance below 0.7% and confirming steady-state energy conservation. The validated thermal model demonstrates that ZCAS glass exhibits stable and predictable heat conduction behaviour under moderate thermal gradients. These findings support the suitability of ZCAS glass whether synthesized from high-purity oxides or sustainable waste-derived precursors such as recycled silica and calcium-rich wastes for applications in optical components, electronic packaging, and thermally stable structural systems.