Design and optimization of a hydrodynamically activated removable protective nose cover for high-speed water-entry vehicles
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https://doi.org/10.54939/1859-1043.j.mst.FMC.2026.108-116Keywords:
Removable nose cover; Hydrodynamic release mechanism; High-speed water entry; Pressure differential activation; Water-trap groove.Abstract
High-speed water entry subjects nose-mounted instrumentation of submersible vehicles, such as torpedoes and oceanographic instruments, to severe hydrodynamic impact loads. Conventional frangible nose covers often exhibit unreliable separation due to material property variations under environmental conditions. This paper presents a novel removable protective nose cover activated purely by hydrodynamic forces. The design consists of shell segments secured by a central nose member and attachment clips; submerged inlet ducts direct water into a trap groove beneath each clip, generating a pressure differential that triggers release. Using Sequential Quadratic Programming (SQP), key geometric and mechanical parameters were optimized to ensure reliable activation at a water-entry velocity of 90 km/h, with a high safety margin against premature release at transonic air speeds. Compared with conventional frangible covers, the proposed design offers greater reliability, repeatability, and environmental insensitivity, providing theoretical formulations and practical guidelines for hydrodynamic release mechanisms in aerospace and marine applications.
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