Intersecting Spherical Hull Form for Manned Submersible Vehicles

摘要

The most used hull form for the design of underwater vehicles is the single sphere or for larger vehicles a cylinder with spherical caps at each end. The objective of this paper is to show the structural advantages of hull geometry in the form of intersecting spheres for multipurpose submersibles. A theoretical discussion explores how a physical arrangement of intersecting structural spheres, reinforcing rings and compression bulkheads results in a structure that is very competitive with the above mentioned conventional hull forms. Extensive finite element analysis (FEA) of the geometry presented supports the basic structural equations. The mechanical structural loading on the submerged hull form is the external seawater pressure loading due to diving at depth. Results of the structural FEA and equations are presented in tabular format and also as color plots of stress and deflection. Some of this work was originally started by the late Clifford Ness, President of Manta Research Corporation. The goal of this effort has been to develop a general-purpose manned underwater vehicle that is adaptable to a variety of deep-water tasks. Some observations from the development of this design conclude that an intersecting spherical hull form results in a more efficient use of usable interior volume especially for smaller submersible vessels. The current standard cylindrical hull form requires a central passageway for crew movement fore and aft of the vessel. Thereby, the entire central volume is unavailable for payload and is not usable space. The intersecting spherical hull form allows multiple passageways and multiple equipment areas for payload within the interior. Thereby, alteration is easy to customize for tasks such as underwater transport, commercial diving, sub-sea survey work, and ocean research. Another observation is the intersecting spherical hull form lends itself to a saucer like disk hull form that has hydrodynamic advantages in underwater handling and maneuverability similar to a Manta fish. These practical advantages of the proposed hull form are the incentives to proceed with the structural analysis and discussion in the paper.