Redesigning the SLOCUM glider for torpedo tube launching

Abstract

Launching gliders from a submarine torpedo tube is of special interest for military operations. This is not currently possible because the wing span needed to achieve a good gliding performance is twice the standard diameter of submarine torpedo tubes. To fit lifting surfaces into small and nonconventional volumes in missiles and unmanned aerial vehicles (UAVs), retractable, compliant, and inflatable wings have been proposed by some researchers. Unfortunately, applying these solutions to underwater gliders would result in complicated wing devices or would require substantial modification to the vehicle. Lowering the wing aspect ratio while keeping constant the initial wing surface would be easier to implement, however, this would substantially degrade glider lifting performance. A possible alternative is the use of ring wings. This study investigates the hydrodynamic properties of a glider equipped with a ring wing specifically designed to fit into a torpedo tube. Specifically, a panel method is employed to compute the lift, induced drag and moment coefficient of a glider with different wing configurations. Modeled results are first compared with experimental data in the case of a glider with standard wing configuration. This study is performed on the Slocum glider due to the availability of experimental data. A numerical study is made of the Slocum glider equipped with a low aspect wing and with a ring wing. Results confirm the degradation of lifting performance of the low aspect ratio configuration. On the other hand, numerical results predict that similar gliding performance can be achieved with a Slocum glider equipped with a ring wing sized to fit the vehicle into a torpedo tube. Results encourage follow-up experimentation of these close lifting surfaces in underwater glider technology.