【作者】 张可新；

【导师】 庞永杰；

【作者基本信息】 哈尔滨工程大学 ， 船舶与海洋结构物设计制造， 2009， 硕士

【摘要】 一直以来,水面高性能船舶的水动力性能研究都是大家关注的热点问题,而作为高性能船舶的一种,对水面滑行艇的相关研究也一直都在进行。滑行艇高速滑行时水动力性能的计算研究是目前船舶水动力计算领域中的一个难点。本论文旨在对棱柱式滑行艇在一定的纵倾状态下,以恒定的速度滑行前进时所受的垂向作用力和纵倾力矩的计算进行初步的研究,为滑行艇的稳定性分析奠定基础。本文采用Faltinsen等人提出的2D+t理论对棱柱式滑行艇的垂向水动力系数和纵倾力矩系数进行数值计算。应用二维的入水分析方法,在随体坐标系内进行定常流动的2D+t分析,将所研究的固连于大地坐标系的平面内的流动,等价于二维变形截面入水所造成的流动。本文中,以势流理论为基础,采用边界元法在时域内求解二维楔形以恒定速度入水的问题,求得楔形体表面的压力分布,对得到的压力分布进行积分,来计算滑行艇体的垂向作用力和纵倾力矩。在二维楔形入水问题的求解计算中,考虑重力的影响、采用线性边界元、四阶龙格-库塔的时间步进模式对问题进行处理,应用伯努利方程来计算楔形体表面的垂向作用力。本文将数值计算的结果与Troesch的模型实验结果进行了比较,验证了文中所采用的方法在滑行艇的水动力计算研究中的可行性,为该问题后续的深入研究指明了方向。更多还原

【Abstract】 The research of the hydrodynamics of the high performance marine vehicle is the hotspot for quite a long time. As a kind of the high performance marine vehicle, the research of the planing hull has been paid a lot of attention by the researchers.The hydrodynamics computation of the planing hull in the state of planing with a high speed is a hard problem in the field of hydrodynamics calculation of marine vehicle. This dissertation aims at the elementary research of the prediction of the vertical force and pitch moment of a prismatic planing hull which is planing forward with a constant high speed and with a constant trim angle, and also provide the basis for the stability analysis of a planing hull.The 2D+t theory that is put forward by Faltinsen is used to numerically calculate the vertical force coefficient and trimming moment coefficient of prismatic planing hulls.The method of two dimensional water entry analysis is used for the steady 2D+t analysis in ship-fixed coordinate system, the flow that is researched in a plane in an earth-fixed coordinate system is equivalent to the flow generated by the water entry of a two dimensional deformable cross section. In this dissertation, the two dimensional water entry problem of a wedge with a constant vertical speed is solved by the boundary element method in the time domain based on the potential theory, and the force distribution on the surface of the wedge is acquired, then the force distribution is integrated to calculate the total vertical force and the pitch moment of the planing hull. In the simulation of the two dimensional water entry problem, the influence of gravity is considered, the linear boundary element and the fourth-order Runge-Kutta time stepping mode is used to solved the problem, in addition, the Bernoulli’s equation is used to calculated the vertical force on the wedge surface.In this dissertation, the numerical results are compared with the Troesch’s experiments results, the feasibility of the numerical method which is used in the dissertation is verified, and the direction for further research in the future is pointed out.更多还原