Transom sterns make prediction of ship's performance characteristics challenging, especially in the partially ventilated regime. Faster, medium fidelity potential flow codes such as the ones based on the Boundary Element Method (BEM) require a special treatment of the free surface boundary condition at the transom in order to correctly predict calm water resistance. Incident waves further complicate the flow kinematics around the vessel and possibly the characteristics of the transom flows, which become important when wave added resistance is considered. In this paper, we investigate the effect of incident waves on the streamwise discontinuity in hull geometry due to varying transom configurations ranging from round bilge to deep-vee sections. Transom flow wave elevations between the fully wetted and fully ventilated regimes are measured in waves and compared with the steady case for two different transoms. The effect of diffracted waves on the transom flow kinematics is analyzed experimentally and the data is used to validate high-fidelity unsteady fully-viscous CFD results from simulations performed in FINE™/Marine.

Keywords:
cfd, wave system, artificial intelligence, incident wave, ventilation factor, free surface wave elevation, unsteady behavior, time history, amplitude, elevation
Subjects:
Information Management and Systems
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2016. The Society of Naval Architects and Marine Engineers
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