Heat exchanger layout for a thermal underwater glider

Thermal glider is a new type of underwater glider which harvests its propulsive energy from the thermocline in the ocean. Compared with traditional electric underwater glider, the thermal glider may achieve a much longer duration and range. The heat exchangers on the underwater glider can be mounted above the hull, below the hull, and by the sides of the hull. In this paper, hydrodynamic analysis is conducted for the thermal glider with the three heat exchanger layout designs using computational fluid dynamics. Impact of the layout design on glide efficiency and static stability is investigated, using lift to drag ratio and dimensionless position lever as the evaluation parameters. Result shows that the thermal glider is statically stable with the heat exchangers. The layout of the heat exchangers greatly affects the static stability of the glider, while little influence has been found on the glide efficiency. It is also found that taking glide efficiency and static stability into consideration, the heat exchangers are better mounted below the hull. The result provides theoretical guidance for thermal glider design.