Structural Design and Performance Analysis of Underwater Tethered Vehicles

An underwater towed vehicle serves as an effective and widely applicable mobile marine observation platform. Existing towed vehicles rely heavily on cables for depth adjustment. They also suffer from poor hydrodynamic efficiency and insufficient instrument space. To address these limitations, this study developed a novel compensation control system. This system regulates the vehicle’s vertical movement and cable deployment by controlling the attack angles of its front and rear hydrofoils. The Myring profile was selected as the base design for the towed vehicle, offering excellent hydrodynamic performance, ample internal space, and cost-effectiveness. To verify the system’s reliability, critical components were meticulously designed and calibrated. Hydrodynamic simulations confirmed that adjusting the hydrofoil angle effectively controls vertical motion, with stress and deformation in the lifting mechanism and cable connectors meeting design specifications. Additionally, the overall drag resistance remains low, while the lift generated by both hydrofoils satisfies depth adjustment requirements. This research provides robust numerical foundations for developing vertical control strategies, optimizing operational conditions, and conducting subsequent sea trials of towed vehicles. Quantitative comparison with the conventional scheme indicates that the proposed structure cuts total drag by 21.6%, boosts depth adjustment efficiency by 47.3%, and achieves a 32% higher hydrofoil lift-drag ratio, accompanied by a structural safety factor of 1.8 and maximum deformation of only 1.711 mm under rated working conditions.