固有周期下阻尼板对半潜式平台阻尼的影响

摘要

To research the free decay motion of a semisubmersible platform in its natural period,a numerical simu-lation was performed to analyze the free decay motion of the heave,rolling,and pitch of a semisubmersible platform using a computational-fluid-dynamics-based method with overlapped grid technology.The accuracy of the method was verified by comparing simulation results with the experimental data.Based on these results, the effect of the width and thickness of the damping plate on the heave, roll, and pitch damping of the semisubmersible platform were investigated at different initial decay positions.The effect mechanism of the damping plate was analyzed from a flow field perspective.The results were as follows:the greater the amplitude of the semisubmersible platform,the stronger the inhibitory effect of the damping plate.Increased damping of the semisubmersible platform is mainly due to the flow separation at the edge of the damping plate,and the width of the damping plate is positively correlated to the heave,roll,and pitch damping of the semisubmersible platform,whereas the thickness of the damping plate is negatively correlated with them.%为了研究半潜式平台在固有周期下的自由衰减运动,本文基于重叠网格技术的计算流体力学(CFD)方法对半潜式平台垂荡、横摇和纵摇自由衰减运动进行数值模拟.利用该方法分别研究了不同初始衰减位置下,阻尼板宽度和厚度对半潜式平台垂荡、横摇和纵摇阻尼的影响规律,并从流场角度分析了阻尼板的作用机理,通过与实验数据对比,验证该方法的准确性.研究结果表明:平台运动幅度越大,阻尼板起到的抑制作用越强,阻尼板边缘处的流动分离是平台阻尼增加的直接原因;阻尼板宽度与平台垂荡、横摇及纵摇阻尼呈正相关,而阻尼板厚度与其呈负相关.