基于弱非线性假定的船舶波浪增阻数值计算

基于船舶在波浪中运动的势流理论的弱非线性假定,对于船舶在迎浪下的波浪增阻进行了数值计算.数值计算将Maruo波浪增阻理论与非线性船舶运动理论相结合.非线性的船舶运动响应采用时域切片法计算,考虑了Froude-Krylov力与静水压力的非线性影响,辐射力与绕射力则保持线性.在船舶运动结果的基础上应用Maruo公式计算波浪增阻.S175集装箱船的计算结果验证了所采用方法的准确性,同时表明所采用方法能够有效考虑波陡对于波浪增阻的影响.在此基础上进一步探究了航速对波浪增阻的非线性特性的影响.

Numerical Calculation of Added Resistance of Ships in#br# Waves Based on Weakly Nonlinear Assumption

Abstract： The added resistance of ships in head waves is calculated under the assumption of weak nonlinearity in potential theory of ship motions. Maruo’s added resistance theory and the nonlinear ship motion theory are combined. The nonlinear ship motions are calculated using a time domain strip method, in which the Froude Krylov force and hydrostatic force are nonlinear while the radiation force and diffraction force are still linear. Then the added resistance is obtained according to Maruo’s formula using the motion results. The computational results for S175 containership are used to validate the accuracy of the implemented methods and the results prove that the influence of wave steepness can be considered effectively. The influence of ship speed on the nonlinearity of added resistance is further investigated.