Mathematical Modeling of Pressure-Sensitive Phase Change Heat Transfer in Multi-Layer Diving Suits

This study presents a mathematical model for simulating heat transfer in a multi-layer diving suit embedded with phase change materials (PCMs) under hydrostatic pressure. The model incorporates nonlinear thermal conductivity and diffusivity that vary with depth-induced pressure, alongside internal metabolic heat generation. A moving boundary problem is formulated using a one-dimensional Stefan model to capture latent heat effects in the PCM layer. The system is solved using a finite difference scheme for time-dependent regions and a boundary value solver for steady-state analysis. Results demonstrate that pressure-dependent thermal resistance enhances insulation at greater depths, while the PCM layer stabilizes internal temperatures near the melting point. The developed model provides a framework for optimizing thermally adaptive protective systems through rigorous mathematical formulations.