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Scenarios of Local Tsunamis in the China Seas by Boussinesq Model

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China Ocean Engineering 2014年第3期28卷 303-316页

作者：赵曦刘桦王本龙 Department of Engineering Mechanics MOE Key Laboratory of HydrodynamicsShanghai Jiao Tong University

The Okinawa Trench in the East China Sea and the Manila Trench in the South China Sea are considered to be the regions with high risk of potential tsunamis induced by submarine earthquakes. Tsunami waves will impact the southeast coast of China if tsunamis occur in these areas. In this paper, the horizontal two-dimensional Boussinesq model is used to simulate tsunami generation, propagation, and runnp in a domain with complex geometrical boundaries. The temporary varying bottom boundary condition is adopted to describe the initial tsunami waves motivated by the submarine faults. The Indian Ocean tsunami is simulated by the numerical model as a validation case. The time series of water elevation and runup on the beach are compared with the measured data from field survey. The agreements indicate that the Boussinesq model can be used to simulate tsunamis and predict the waveform and runup. Then, the hypothetical tsunamis in the Okinawa Trench and the Manila Trench are simulated by the numerical model. The arrival time and maximum wave height near coastal cities are predicted by the model. It turns out that the leading depression N-wave occurs when the tsunami propagates in the continental shelf from the Okinawa Trench. The scenarios of the tsunami in the Manila Trench demonstrate significant effects on the coastal area around the South China Sea.

关键词： tsunami Boussinesq model Indian Ocean Okinawa Trench Manila Trench

WATER ENTRY OF A WEDGE BASED ON SPH MODEL WITH AN IMPROVED BOUNDARY TREATMENT

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Journal of Hydrodynamics 2009年第6期21卷 750-757页

作者： GONG Kai LIU Hua wang ben-long Department of Engineering Mechanics Shanghai Jiao Tong University Shanghai 200240 China State Key Laboratory of Ocean Engineering Shanghai Jiao Tong University Shanghai 200240 China

The hydrodynamic problem of a two-dimensional wedge entering water is studied based on Smoothed Particle Hydrodynamics （SPH） model. A non-reflection boundary treatment for SPH method is proposed to reduce the reflection of sound waves. The boundary pressure is obtained using an improved coupling boundary treatment approach, which is validated by comparing the simulation results with experimental and analytical results in literature. A series of cases with different initial entering velocities are simulated. The maximum force on the wedge and the corresponding time required to reach it for the different cases of initial entering velocities of the wedge are obained and fitted into formulas against the initial entering velocity of the wedge. The maximum drag coefficients of the wedge for the different cases with Froude number greater than 2 are all near the value of 0.91.

关键词： water entry Smoothed Particle Hydrodynamics (SPH) non-reflection boundary

Numerical simulations of wake signatures around high-speed ships

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Journal of Hydrodynamics 2014年第6期26卷 986-989页

作者：王本龙郭晓宇刘桦何辰 School of Naval Architecture Ocean and Civil Engineering and MOE Key Laboratory of Hydrodynamics Shanghai Jiao Tong University Xi’an Precision Engineering Institute

Navier-Stokes equations are solved to obtain the near field flow and to reveal the generation of droplets due to the breaking of the bow wave. With an adaptive refinement of the Octree mesh, the fine scale flow characteristics, the wave breaking and the splashing are well simulated. For high-speed ships, the V-shape ship wave pattern with the angle smaller than the classical Kelvin angle is confirmed by the present numerical results, which can also be applied to the catamaran. Comparisons of the vertical velocity distributions induced by the mono-hull ship and the catamaran are made at different locations in the wake regions.

关键词： bow wave breaking wave volume of fluid method

一种适用于非均匀地形的高阶Boussinesq水波模型

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应用数学和力学 2005年第6期26卷 714-722页

作者：王本龙刘桦上海交通大学工程力学系上海200240

　推导了适用于变地形情况的高阶Boussinesq波浪模型·　该模型采用自由表面边界条件作为时间步进方程,利用势函数满足的Laplace方程的解析解形式建立了自由表面边界速度和底面边界速度之间的关系,使得问题封闭·　以0.5倍相对水深处的... 详细信息

　推导了适用于变地形情况的高阶Boussinesq波浪模型·　该模型采用自由表面边界条件作为时间步进方程,利用势函数满足的Laplace方程的解析解形式建立了自由表面边界速度和底面边界速度之间的关系,使得问题封闭·　以0.5倍相对水深处的速度为基本未知量,在对Laplace方程解析解进行级数求逆时保留水深梯度的高阶项,改进了速度场的Taylor展开式·　对于线性特性,进行了线性浅化和Booij反射的验证性计算·　为了检验有背景流动情况下拓展的Boussinesq模型的性态,对波_流相互作用问题进行了数值模拟·　数值计算结果与现有理论解或其他完全势流的数值解吻合良好。

关键词：高阶Boussinesq方程波流相互作用变地形

关于采用高阶Boussinesq方程求解波浪散射问题的注记

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力学季刊 2005年第3期26卷 346-353页

作者：王本龙刘桦上海交通大学工程力学系上海200030

本文讨论了采用高阶Boussinesq方程模拟波浪散射时对基本速度变量位置的局部光滑处理方法。通过光滑局部基本速度变量的取值深度,减小其高阶导数项的量值、加快级数收敛速度进而改善模型方程求解深水波浪散射问题的能力。对于底部边界... 详细信息

本文讨论了采用高阶Boussinesq方程模拟波浪散射时对基本速度变量位置的局部光滑处理方法。通过光滑局部基本速度变量的取值深度,减小其高阶导数项的量值、加快级数收敛速度进而改善模型方程求解深水波浪散射问题的能力。对于底部边界具有一阶导数不连续的情况,通过局部光滑,可以将基本速度变量取值深度尖角转化为圆角过渡,从而改善速度分布。对于其它任意变化的底部边界,为了减少高阶底坡导数项的影响,在曲率和高阶底坡导数项与斜率具有相同量级的情况下亦需要对基本速度变量的取值深度局部光滑。数值计算结果表明本文提出的光滑技术可以很好地改善Boussinesq方程模拟浅水波和深水波在斜坡地形上散射问题的能力。

关键词： Boussinesq方程 Laplace方程精确解波浪散射反射散射问题方程求解高阶波浪光滑处理收敛速度

A review of studies of mechanism and prediction of tip vortex cavitation inception

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Journal of Hydrodynamics 2015年第4期27卷 488-495页

作者：张凌新张娜彭晓星王本龙邵雪明 State Key Laboratory of Fluid Power Transmission and Control Department of Mechanics Zhejiang University China Ship Scientific Research Center School of Naval Architecture Ocean and Civil Engineering Shanghai Jiao Tong University

The inception of the tip vortex cavitation（TVC） is a very important problem in cavitation researches. The study of the mechanism of the TVC inception is not only conducive to its prediction, but also helps to suppress or suspend the occurrence of cavitation. In this paper, the research progresses on the TVC inception including theoretical, experimental and numerical studies mainly in the last two decades are reviewed. It is shown that the TVC inception is affected by complicated factors, such as the water quality, the average pressure and the fluctuating pressure. In the scaling law for the determination of the TVC inception, all these factors are considered. To precisely describe the scaling law, more investigations are needed to understand the effects of the water quality and the fluctuating pressure.

关键词： tip vortex cavitation inception scaling law

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基于谱元法的梢隙涡流场高保真隐式大涡模拟

水动力学研究与进展（A辑） 2021年第3期36卷 453-461页

作者：王昭予王本龙徐辉上海交通大学上海200240

该文采用谱元法结合基于谱消去黏性的隐式大涡模拟对水翼梢隙涡流场进行了数值计算,研究了在两种无量纲间隙宽度τ=0.3和τ=1时,梢隙内部及尾缘下游的梢隙涡演化过程。研究发现,τ=0.3时,梢隙内部流动形态为横向射流,水翼压力面梢部的... 详细信息

该文采用谱元法结合基于谱消去黏性的隐式大涡模拟对水翼梢隙涡流场进行了数值计算,研究了在两种无量纲间隙宽度τ=0.3和τ=1时,梢隙内部及尾缘下游的梢隙涡演化过程。研究发现,τ=0.3时,梢隙内部流动形态为横向射流,水翼压力面梢部的流体在分离后以附着涡形式附着在水翼梢部端面处。吸力面的梢隙涡在形成后独立向下游发展,其结构保持了轴对称的形态。而τ=1时,水翼压力面的分离涡在压差作用下向吸力面发展,并在尾缘附近和梢隙涡发生融合。融合过程中产生的二次涡破坏了梢隙涡的对称性。研究还发现,两种梢隙宽度下的梢隙涡核内均存在轴向速度亏损,其强度也在演化过程中不断下降,同时水翼梢部端面附近湍动能远高于端壁边界层内的对应值,涡核区域的雷诺偏应力和剪切应变空间分布存在相位差。

关键词：梢隙涡谱元法隐式大涡模拟谱消去黏性法

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海沟内海底地震激发的表面波动

力学季刊 2007年第2期28卷 195-202页

作者：赵曦王本龙刘桦上海交通大学船舶海洋与建筑工程学院上海200030

通过底面运动学边界条件引入底面运动影响,采用高阶Boussinesq方程计算了光滑海底变形引起的表面波动形态。对于线性问题,与线性势流波浪理论进行了比较,二者结果符合良好。运用高阶Boussinesq波浪模型,针对冲绳海沟的实际地形,模拟海... 详细信息

通过底面运动学边界条件引入底面运动影响,采用高阶Boussinesq方程计算了光滑海底变形引起的表面波动形态。对于线性问题,与线性势流波浪理论进行了比较,二者结果符合良好。运用高阶Boussinesq波浪模型,针对冲绳海沟的实际地形,模拟海沟内不同震级的海底地震激发的海啸,分析了不同强度地震引起的表面波扰动形态及其非线性和色散效应。

关键词：海啸传递函数 Boussinesq方程海沟海底地震

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SPH固壁边界处理方法的改进

力学季刊 2008年第4期29卷 507-514页

作者：龚凯刘桦王本龙上海交通大学工程力学系上海200240

提出一种适用于光滑质点水动力学(SPH)方法的改进的边界处理方法。在这种方法中,边界粒子的压力可通过其周围的流体粒子的压力插值得到,从而改进了耦合边界法在边界上压力不准的问题。运用这种改进的边界处理方法模拟了二维方形水箱中... 详细信息

提出一种适用于光滑质点水动力学(SPH)方法的改进的边界处理方法。在这种方法中,边界粒子的压力可通过其周围的流体粒子的压力插值得到,从而改进了耦合边界法在边界上压力不准的问题。运用这种改进的边界处理方法模拟了二维方形水箱中的非线性晃荡问题以及二维楔形体自由入水问题。模拟结果与实验结果吻合较好,证明了此改进的边界处理方法是有效的。

关键词：光滑质点水动力学(SPH) 边界处理晃荡人水