Hydrodynamic analysis and optimization of the Titan submarine via the SPH and Finite–Volume methods

This work presents a numerical analysis of the hydrodynamics of a conceptual submarine designed by NASA to operate in the liquid hydrocarbon seas of Titan, the largest Saturnian moon. Operational conditions of the “Titan submarine” include navigation at the free surface as well as deeply submerged. For the former, a numerical flow analysis is conducted using Smoothed Particle Hydrodynamics (SPH), one of the most advanced particle methods with high suitability for the simulation of free-surface flow. The open-source SPH code adopted in this research is benchmarked against results of flow past a boat on Earth from experimental and numerical work of other authors. This validation study corroborates the effectiveness of SPH in modeling flow past marine vehicles. In the deeply-submerged regime, a mesh-based approach is adopted, i.e. the Finite–Volume method (FVM), using well-established commercial software. Preliminary calculations of drag, thrust and power for the Titan submarine are then obtained for both surfaced and submerged conditions. The estimation of the total drag acting on the submarine allows to identify an upper bound for thrust and power requirements for efficient navigation. Results from this study also include flow visualization around the hull and final design recommendations, as well as an assessment of the necessary power requirements for an efficient exploration of Titan's seas.