Date of Award
Master of Science (MS)
Ocean Engineering and Marine Sciences
A numerical study of the DARPA SUBOFF model using computational fluid dynamics (CFD) has been presented for developing a CFD application procedure to compute the hydrodynamic performance of underwater vehicles, including submarines. Several configurations, such as bare hull, fairwater, sterns, and/or ringwing-appended hulls, were examined for the straight-ahead, steady translation and turning, and self-propelled conditions. A systematic study was conducted to ensure an adequate computational domain expansion and reasonable prism layer mesh properties for solutions independent of the parameters. The hydrodynamic forces exerted on the hull and the appendages were verified and validated in accordance with a published methodology under a given test condition. Subsequently, several sets of simulations were performed by varying parameters, such as velocity and drift angle, and the results were compared against published experimental data. The skin friction and pressure distributions over the hull were presented for additional validation. The INSEAN E1619 propeller was adopted for self-propulsion simulations, and the computed self-propulsive performance was compared with previously published numerical results. The effect of the water surface on the straight-ahead resistance was studied for different submergence scenarios at a given Froude number. Furthermore, self-propulsive simulations with a water surface were performed, and the solutions were compared with those of the computational model without a water surface. The CFD application procedures to compute the straight-ahead resistance, steady translation, steady turning, self-propulsive performance, and water surface effects developed using the SUBOFF submarine can serve as the standard methods and guidelines for computing the hydrodynamic performance of underwater vehicles, including submarines, in future numerical studies. Moreover, they can be utilized to comprehensively predict the hydrodynamic performance of these vehicles and analyze complicated local flow characteristics to improve future designs by accounting for more complex, unsteady problems, such as transitional flow and propeller-hull interactions.
Takahashi, Kenshiro, "Numerical Simulations of Comprehensive Hydrodynamic Performance of DARPA SUBOFF Submarine" (2019). Theses and Dissertations. 1183.
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