The hydrodynamic analysis of a new semi-small waterplane area twin hull (SWATH) suitable for various applications such as small and medium size passenger ferries is presented. This may be an attractive crossover con...The hydrodynamic analysis of a new semi-small waterplane area twin hull (SWATH) suitable for various applications such as small and medium size passenger ferries is presented. This may be an attractive crossover configuration resulting from the merging of two classical shapes: a conventional SWATH and a fast catamaran. The final hull design exhibits a wedge-like waterline shape with the maximum beam at the stem; the hull ends with a very narrow entrance angle, has a prominent bulbous bow typical of SWATH vessels, and features full stern to arrange waterjet propellers. Our analysis aims to perform a preliminary assessment of the hydrodynamic performance of a hull with such a complex shape both in terms of resistance of the hull in calm water and seakeeping capability in regular head waves and compare the performance with that of a conventional SWATH. The analysis is performed using a boundary element method that was preliminarily validated on a conventional SWATH vessel.展开更多
Based on the second order hydroelasticity theory of ships, the numerical methods and the calculated results of the non-linear hydroelastic responses of a ship traveling in rough seas were investigated. The non-linear ...Based on the second order hydroelasticity theory of ships, the numerical methods and the calculated results of the non-linear hydroelastic responses of a ship traveling in rough seas were investigated. The non-linear hydrodynamic actions induced by the rigid body rotations and the variations of instantaneous wetted surface area were included in the second order analysis. The first order wave potentials and responses, which are sure to make the major contributions to the second order hydrodynamic actions, were obtained by employing the translating and pulsating source Green function and the Kelvin steady wave flow solution based on the linear three-dimensional hydroelasticity theory. The influences of the forward speed and the steady wave flow on the responses, and the differences of the predicted non-linear responses were illustrated by the numerical examples of a SWATH ship traveling with forward speed of 12 kn in irregular waves.展开更多
文摘The hydrodynamic analysis of a new semi-small waterplane area twin hull (SWATH) suitable for various applications such as small and medium size passenger ferries is presented. This may be an attractive crossover configuration resulting from the merging of two classical shapes: a conventional SWATH and a fast catamaran. The final hull design exhibits a wedge-like waterline shape with the maximum beam at the stem; the hull ends with a very narrow entrance angle, has a prominent bulbous bow typical of SWATH vessels, and features full stern to arrange waterjet propellers. Our analysis aims to perform a preliminary assessment of the hydrodynamic performance of a hull with such a complex shape both in terms of resistance of the hull in calm water and seakeeping capability in regular head waves and compare the performance with that of a conventional SWATH. The analysis is performed using a boundary element method that was preliminarily validated on a conventional SWATH vessel.
文摘Based on the second order hydroelasticity theory of ships, the numerical methods and the calculated results of the non-linear hydroelastic responses of a ship traveling in rough seas were investigated. The non-linear hydrodynamic actions induced by the rigid body rotations and the variations of instantaneous wetted surface area were included in the second order analysis. The first order wave potentials and responses, which are sure to make the major contributions to the second order hydrodynamic actions, were obtained by employing the translating and pulsating source Green function and the Kelvin steady wave flow solution based on the linear three-dimensional hydroelasticity theory. The influences of the forward speed and the steady wave flow on the responses, and the differences of the predicted non-linear responses were illustrated by the numerical examples of a SWATH ship traveling with forward speed of 12 kn in irregular waves.