Computational Investigation of Non-body-of-Revolution Hull Form Maneuvering Characteristics

Abstract

Maneuvering characteristics for traditional body-of-revolution (BOR) hull forms are well understood through decades of testing, while less traditional non-body-of-revolution (Non-BOR) hull forms are not nearly as well understood. A computational investigation on the maneuvering capability for two Non-BOR hull forms (Single and Twin Tail stern configurations) and an equivalent BOR hull form is completed, and compared to prior experimental tests. Initially, global forces and moments on the hull forms over various static angles of attack are computed and studied. Next, steady turn computations are used to determine global forces and moments on the hull forms over various turning radii. Force and moment information from the static and steady turn computations are combined to compute indices of stability for each hull form. Stability indices are used as a means of quantifying maneuvering stability for all of the hull forms in the vertical and horizontal planes. Computationally predicted stability indices displayed the same maneuvering characteristics as previous experiments. The Twin Tail hull form was shown to be highly stable in both the vertical and horizontal planes. The Single Tail hull form was unstable in the vertical plane and highly stable in the horizontal plane. The BOR proved to be marginally stable to stable in both planes. The results of this study show that the Twin Tail hull form would be more suitable from a maneuvering standpoint than the Single Tail hull form in future Non-BOR design studies.