Experimental and numerical investigation on the seakeeping performance of a pentamaran with tilting aft side hulls

Significant potential remains for investigating the seakeeping performance of pentamarans both experimentally and numerically. In this study, a numerical model is developed on STAR-CCM+(R) platform, utilizing the dynamic fluid body interaction module and overset mesh technology to integrate the vehicle model with the numerical wave tank. The numerical model is validated by experimental data for a pentamaran moving in regular head waves. Numerical simulations, as well as spectrum analysis-based short-term forecasts, are performed under various cases with different wavelengths, forward speeds, wave encounter angles, and the inclination angles of the aft side hulls. The results demonstrate that the increase in forward speed can lead to the enhancement of added resistance and motion responses and a leftward shift of the resonance range, especially in head waves. The pentamaran experiences extreme added resistance and roll when encountering beam waves and extreme pitch and heave in head waves. The optimal inclination angle of the aft side hulls is 105 degrees. For pentamaran sailing in irregular waves, the Froude number of 0.5 and the wave encounter angle of 135 degrees are advisable in order to achieve minimal heave and pitch responses and moderate roll responses.