Computational Investigation of the DTMB Series 66 Hull Forms

Abstract

In this study, Reynolds Averaged Navier-Stokes (RANS) computations are used to shed insight into modeling effects and ship design characteristics of Non-Body-of-Revolution (NonBOR) hull forms. Traditionally, submarines and underwater bodies have used Body-ofRevolution (BOR) hull forms; however, NonBORs are of interest due to their increased payload capability. Thus, a systematic study of the David Taylor Model Basin (DTMB) Series 66 NonBOR hull forms is undertaken. Computations performed in this study are complimentary to experimental tow tank tests performed by Roddy, El-Taher, Hess, Junghans, and Jiang 4 at the Naval Surface Warfare Center (NSWC). The Series 66 hull forms include a traditional BOR hull as well as NonBOR Single and Twin Tail hulls that are offshoots of the BOR based on span-wise stretching from the centerline. Initially, RANS computations are used to quantify experimental tow tank modeling effects like strut wake interference and free surface blockage on predicted axial resistance. Results for the Twin Tail hull under straight-ahead conditions show that there is negligible strut wake interference and a 3% increase in predicted resistance due to the presence of a free surface. Next, RANS computations are used to compute global forces and moments for the various bodies under in-plane vertical and horizontal incoming flow conditions. The NonBOR hull forms provide greater lifting force in the vertical plane, and similar side forces in the horizontal plane as compared to the BOR. Between the two NonBOR hulls the Twin Tail offers more lifting force and similar pitching moments as compared to the Single Tail hull. Finally, features like propeller inflow and cross flow separation characteristics that would be of interest to a ship designer are analyzed.