Simulation of Phase Transition Process of Underwater Thermal Glider Based on FLUENT

The solid-liquid phase transition is key to enable a thermal glider to absorb and utilize the ocean temperature difference energy. The solid-liquid phase transition process is affected by many factors. Herein, based on the existence of natural convection, the effect of pressure on the solid-liquid phase transition process of a thermal glider is introduced. The simulation model of phase-change heat transfer in the heat pipe of an underwater thermal glider is established, and the heat pipe heat-transfer process under different pressures is simulated using ANSYS FLUENT 18.0 software. It is discovered that the pressure can change the melting temperature of the material and affect the phase transformation. With the increase in pressure, the melting temperature of the material increases, and the time required to achieve complete melting under the same temperature increases however, the time required for solidification decreases. If the melting point is higher than the temperature of the warm water layer, then the phase-change material cannot complete the phase-change process, and the thermal glider will not be able to operate stably. The simulation results facilitate the study of the phase-transition process of underwater thermal gliders.