CFD is becoming an integral part of the vessel's innovation and design process. Our work attempts to predict hull hydrodynamics of a semi- planing wave-piercing craft both in calm water and waves by numerical simulations based on CFD. Numerical methods solving unsteady RANS equations were adopted. Resistance and hull motions of a slim semi-planing wave-piercing craft in calm water and waves were calculated. Numerical results are compared to experimental results. Comparisons show that although the special hull shape and operation mode cause trouble, numerical simulations based on CFD are still suitable tools for hydrodynamics prediction of a semi-planing wavepiercing craft, and can offer vivid results of sufficient accuracy and reliability. In addition, a simulation in the steep wave was conducted to figure out how a semi-planing wave-piercing craft behaves in an adverse sea condition at high speed.
Wave-piercing boats, especially high-speed wave-piercing boats, are popular in recent years. When a wave is encountered, a wave-piercing boat pierces through the water rather than ride over the top. A bow of a wave-piercing boat is slender, and the freeboard is usually tumblehome or vertical rather than flared. This kind of bow shape can reduce the wave disturbance and make a hull move softly in waves. A semi- planing hull is a good alternative for a high speed craft. A semi-planing wave-piercing craft combines a semi-planing hull and a wave-piercing bow and tries to take advantages of both of them.
Published studies on mono wave-piercing boats focus on a wavepiercing tumblehome vessel published by the US Office of Naval Research (ONR). Studies on the ONR tumblehome hull were conducted mostly for safety consideration such as parametric roll (Mccue et al., 2007; Olivieri et al., 2008; Sadat-Hosseini et al., 2010), stability (Bassler et al., 2007a; Hashimoto, 2009), and some other topics (Carrica et al., 2008; Umedao et al., 2008). In addition, Bassler (2007b) experimentally measured the hydrodynamic coefficients on the ONR hull.
