基于二维半理论的船舶水动压力预报方法研究

  目的  为了研究船舶在波浪中运动预报的非线性切片方法，从线性时域切片方法出发进行初步探究。  方法  在切片假设前提下，推导二维剖面满足的边界条件，求解二维剖面的水动力系数，进而求解全船的受力及运动响应，并采用方向导数的数值差分方法计算速度势沿船长的偏导数。计算Wigley I船的水动力系数及KVLCC2船、8 000 TEU集装箱船的运动响应，并与其他相关方法的计算值及试验值开展对比研究。  结果  结果显示，所得结果与模型试验结果总体上吻合良好，具有良好的适用性。  结论  所做研究对后续开展船舶非线性时域切片运动预报具有一定的借鉴意义。

Theory and calculation of ship responses in regular waves

  Objectives  In order to study the nonlinear strip method for prediction of ship motions in waves, this paper develops a linear time-domain strip method to make a preliminary exploration.  Methods  Under the assumptions of strip theory, the boundary conditions for 2D section are established, and after the calculation of hydrodynamic force coefficient of 2D section, the force and motion response of the whole ship are solved. The numerical differentiation algorithm is used to solve the partial derivative of velocity potential along the ship length direction. The calculated hydrodynamic force coefficient of Wigley I ship and the calculated motion response of KVLCC2 and a 8 000 TEU container ship are compared with the calculated and test values of other related methods.  Results  It is found that the results are generally consistent with the model test results, and can be applied in practice.  Conclusions  This study, to some extent, lays a basis for the future research on the nonlinear time-domain strip method for ship motion prediction.