Rankine panel methods have been studied for solving 3D seakeeping problems of a ship with forward speed and oscillatory motions. Nevertheless, there is a drawback in the numerical method for satisfying the radiation condition of outgoing waves at low frequencies, because the waves generated ahead of a ship reflect from the outward computational boundary and smear the flow around the ship. The so-called panel shift technique has been adopted in the frequency-domain Rankine panel method, which is effective when the generated waves propagate downstream of a ship. In this paper, in addition to this conventional panel shift method, Rayleigh’s artificial friction is introduced in the free-surface boundary condition to suppress longer wave components in a computational region apart from the ship. With this practical new method, it is shown that there is no prominent wave reflection from the side and/or upstream computational boundaries even in the range of low frequencies. As a consequence, the unsteady pressure, hydrodynamic forces, wave-induced ship motions, added resistance are computed with reasonable accuracy even in following waves and in good agreement with measured results in the experiment using a bulk carrier model which is also conducted for the present study.
Improvement of Rankine Panel Method for Seakeeping Prediction of a Ship in Low Frequency Region
- Views Icon Views
- Share Icon Share
- Search Site
Yasuda, E, Iwashita, H, & Kashiwagi, M. "Improvement of Rankine Panel Method for Seakeeping Prediction of a Ship in Low Frequency Region." Proceedings of the ASME 2016 35th International Conference on Ocean, Offshore and Arctic Engineering. Volume 7: Ocean Engineering. Busan, South Korea. June 19–24, 2016. V007T06A001. ASME. https://doi.org/10.1115/OMAE2016-54163
Download citation file: