基于三维势流理论的耐波性数值预报

摘要

准确预报船体运动响应对于砰击等波浪载荷的计算以及合理结构设计具有重要意义。船舶在大幅波浪中的运动呈明显的非线性，而现阶段耐波性预报多采用线性切片方法。三维水动力分析软件 WASIM基于时域势流理论，采用 Rankine面元法预报船舶在波浪中的运动响应，并考虑了多种非线性因素。本文以标模 DTMB5512为对象，采用 WASIM预报其在不同航速下的耐波性，并与基于线性切片理论的计算结果和模型试验结果进行对比。结果表明：利用 WASIM计算得到的船体运动响应比其他方法更接近试验值，合理体现了船舶在风浪中的实际耐波性能。因此，利用 WASIM能够较好地评估船舶在波浪中的非线性耐波特性。%Accurate seakeeping perediction is of great significance to the calculation of slamming and other ship wave loads. Though the motion response of ship in large amplitude waves presents obvious nonlinearity, the linear strip theory is still adopted for most seakeeping predictions at the present stage. WASIM is a three dimensional hydrodynamic analysis software based on potential flow theory in time domain, it can predict ship motion response in waves with rankine panel method and takes many nonlinear factors into consideration. In this paper software WASIM was used to predict the seakeeping performance of standard model DTMB5512 at different speed, meanwhile the calculation results by WASIM were compared with those by the linear strip method and those by experiment. As a result, it indicated that the data of ship motion response calculated by WASIM are much closer to experimental value than others and reflected the actual seakeeping characteristics in waves. Therefore, it can be concluded that WASIM can give a better evaluation of the nonlinear seakeeping characteristics of ship in large amplitude waves.