Research on Numerical, Experimental and Method on Nonlinear

非线性数值、实验与方法研究

• 批准号: 13450403
• 负责人: NAITO Shigeru
• 金额: $ 10.56万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-13450403/
• 关键词: Particle Method; Strong Nonlinearity; Hydrodynamic Wave Force; Pressure; Time-Space Mean Value; Impulse; Large Amplitude Motion of Floating Body; Deck Wetness; Impulsive Force; 強非線形; 浮体の大振動幅動揺

The following is research conclusions in three-year research period.1.The effectiveness of MPS method is shown by comparison between experiments and calculations. We ourselves confirmed with experiments that MPS method can explain strong nonlinear impulsive phenomena, for example slamming and deck wetness.2.MPS method needs the enormously computational times. To solve this difficulty, we have developed two subjects. The first one is that for dividing calculation fluid field a wave absorbing system equipped with at a boundary of a calculation fluid field is developed. The second one is that to reduce computation times, w e completed parallel computational scheme. As a result we can make a new system that refraction waves are not in calculation fluid field.3.We expand the MPS computer code to 3-dimensional program, therefore we can make 3 dimensional nonlinear phenomena clear.4.By using it, we can calculate hydrodynamic force acting on ships with advance velocity. We showed some numerical examples on subjects. Although until now we've not been able to calculate porpoising phenomenon, with this MPS method we can calculate the phenomena.5.When we calculate hydrodynamic force acting on obstacles, the results have an unreasonable high frequency fluctuation. To decrease this fluctuation we introduced an auxiliary equation. As a result, the fluctuation can be reduced. We can open the new perspective to calculate nonlinear hydrodynamic forces acting on a body with high accuracy.6.To distribute the MPS method including our new developed results, we submitted papers, attended the international and domestic conferences and discussed on it. From all over the world we got discussions, questions on the new method.

通过三年的研究，得出以下研究结论：1.通过实验与计算的对比，验证了MPS方法的有效性。我们自己也通过实验证实了MPS方法可以解释强非线性的冲击现象，例如砰击和甲板潮湿。为了解决这个问题，我们开发了两个主题。第一种是为了划分计算流场，开发了在计算流场边界处配备的消波系统。二是为了减少计算时间，我们完成了并行计算方案。3.将MPS程序扩展为三维程序，使三维非线性现象更加清晰; 4.利用MPS程序可以计算船舶在前进速度下所受的水动力。我们展示了一些关于主题的数字示例。虽然目前我们还不能计算海豚现象，但利用MPS方法可以计算海豚现象。5.在计算作用于障碍物上的水动力时，计算结果存在不合理的高频波动。为了减少这种波动，我们引入了一个辅助方程。结果，可以减少波动。6.为推广MPS方法，包括我们的新发展成果，我们提交了论文，参加了国际和国内的会议和讨论，得到了来自世界各地的讨论和质疑。

项目成果

M.Sueyoshi, S.Naito: "Applications of MPS Method to Violent Free Surface Problems on Marine Engineering"Proceedings of 8^<th> Symposium on Nonlinear Free-Surface Flows. 53-55 (2002)

M.Sueyoshi、S.Naito：“MPS 方法在海洋工程中暴力自由表面问题中的应用”第 8 届非线性自由表面流研讨会论文集。

Makoto Sueyoshi: "A Numerical Study of Very Large Motion of Floating Body by Practicle Method"Proc. of Asia/Pacific Workshop on Marine Hydrodynamics. 146-150 (2002)

Makoto Sueyoshi：“浮体超大运动的实践方法数值研究”Proc。

末吉 誠, 内藤 林: "粒子法による流体の強非線形現象に関する大規模3次元計算-PCクラスタ上での百万点超の粒子数に対する並列処理-"関西造船協会誌. 第241号(印刷中). (2004)

Makoto Sueyoshi、Hayashi Naito：“使用粒子法对流体中的强非线性现象进行大规模三维计算 - 在 PC 集群上并行处理超过一百万个粒子 -”《关西造船协会杂志》第 241 期（目前发表于 2017 年）打印））（2004）。

Makoto Sueyoshi, Shigeru Naito: "A Numerical Study of Very Large Motion of Floating Body by Particle Method"Proc.of Asia Pacific Workshop on Marine Hydrodynamics. 146-150 (2002)

Makoto Sueyoshi、Shigeru Naito：“基于粒子法的浮体超大型运动的数值研究”亚太海洋流体动力学研讨会论文集。

S.Naito, M.Sueyoshi, T.Ohashi: "Study on Particle Method with Small Size Calculation Domain"Journal of Kansai Society of Naval Architects of Japan. 240. 109-114 (2003)

S.Naito、M.Sueyoshi、T.Ohashi：“小尺寸计算域的粒子法研究”日本关西造船学会会刊。