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Journal of Hydrodynamics 2006年第1期18卷 63-69页

作者： FENG Xiu-fang TIAN Zhen-fu dai shi-qiang shanghai institute of applied mathematics and mechanics Shanghai University Shanghai 200072 China School of mathematics and Computer Science Ningxia University Yinchuan 750021 China

A new exponential-type weighted implicit difference schcme for solving the Burgers equation was developed and iterated by using the Alternating Group Explicit （Age） method which has the obvious property of parallelism. The stability of the method was analyzed with linearization procedure. A model problem was numerically solved with the proposed scheme. The results show that the method is superb or to some existing schemes.

关键词： Burgers equation exponential type alternating group explicit method stability

FLEXURAL-GRAVITY WAVES DUE TO TRANSIENT DISTURBANCES IN AN INVISCID FLUID OF FINITE DEPTH

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Journal of Hydrodynamics 2008年第2期20卷 131-136页

作者： LU Dong-qiang LE Jia-chun dai shi-qiang shanghai institute of applied mathematics and mechanics Shanghai University Shanghai 200072 China shanghai Key Laboratory of mechanics in Energy and Environment Engineering Shanghai 200072 China

The dynamic response of an ice-covered fluid to transient disturbances was analytically investigated by means of integral transforms and the generalized method of stationary phase. The initially quiescent fluid of finite depth was assumed to be inviscid, incompressible, and homogenous. The thin ice-cover was modeled as a homogeneous elastic plate. The disturbances were idealized as the fundamental singularities. A linearized initial-boundary-value problem was formulated within the framework of potential flow. The perturbed flow was decomposed into the regular and the singular components. An image system was introduced for the singular part to meet the boundary condition at the fiat bottom. The solutions in integral form for the vertical deflexion at the ice-water interface were obtained by means of a joint Laplace-Fourier transform. The asymptotic representations of the wave motion were explicitly derived for large time with a fixed distance-to-time ratio. The effects of the finite depth of fluid on the resultant wave pattems were discussed in detail. As the depth increases from zero, the critical wave number and the minimal group velocity first increase to their peak values and then decrease to constants.

关键词： waves ice-cover transient disturbances asymptotic group velocity

Study on One-Dimensional Model of Traffic Flow with Stochastic Deceleration via Lattice Boltzmann Method

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Journal of shanghai university(English Edition) 2001年第2期5卷 104-106页

作者： XUE Yu, DONG Li yun, dai shi qiang shanghai institute of applied mathematics and mechanics, shanghai university, shanghai 200072, china shanghai institute of applied mathematics and mechanics Shanghai University Shanghai China

One dimensional traffic model was studied with the consideration of stochastic deceleration by using the lattice Boltzmann method. The evolution equation for vehicle density was derived, which has the form of the Burgers equation exhibiting the effect of viscosity corresponding to the deceleration. The simulation with the model shows that the variation of vehicle density in space tends to a periodic one, which implies the existence of kinematic waves in the 1D traffic flow and coincides with theoretical prediction.

关键词： lattice Boltzmann method traffic flow Burgers equation

AN INTEGRAL EQUATION DESCRIBING RIDING WAVES IN SHALLOW WATER OF FINITE DEPTH

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Journal of Hydrodynamics 2003年第5期15卷 70-74页

作者： An Shu ping, Le Jia chun, dai shi qiang shanghai institute of applied mathematics and mechanics, shanghai university, shanghai 200072, china shanghai institute of applied mathematics and mechanics Shanghai University Shanghai 200072 China

An integral equation describing riding waves, i. e. , small-scaleperturbation waves superposed on unperturbed surface waves, in shallow water of finite depth wasstudied via explicit Hamiltonian formulation, and the water was regarded as ideal incompressiblefluid of uniform density. The kinetic energy, density of the perturbed fluid motion was formulatedwith Hamiltonian canonical variables, elevation of the free surface and the velocity potential atthe free surface. Then the variables were expanded to the first order at the free surface ofunperturbed waves. An integal equation for velocity potential of perturbed waves on the unperturbedfree surface was derived by conformal mapping and the Fourier transformation. The integral equationcould replace the Hamiltonian canonical equations which are difficult to solve. An explicitexpression of Lagrangian density function could be obtained by solving the integral equation. Themethod used in this paper provides a new path to study the Hamiltonian formulation of riding wavesand wave interaction problems.

关键词： surface waves water of finite depth hamiltonian formulation riding waves integral equation wave interaction

A human-sensitive frequency band vibration isolator for heavy-duty truck seats

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applied mathematics and mechanics(English Edition) 2024年第10期45卷 1733-1748页

作者： Qingqing LIU Shenlong WANG ge YAN Hu DING Haihua WANG qiang shi Xiaohong DING Huijie YU School of Mechanical Engineering University of Shanghai for Science and Technology State Key Laboratory of Mechanical System and Vibration School of Mechanical Engineering Shanghai Jiao Tong University shanghai Key Laboratory of mechanics in Energy Engineering Shanghai Frontier Science Center of Mechnoinformatics Shanghai Institute of Applied Mathematics and MechanicsSchool of Mechanics and Engineering Science Shanghai University State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body College of Mechanical and Vehicle Engineering Hunan University Yanfeng Adient Seating Co. Ltd. College of Mechanical and Electrical Engineering Jiaxing Nanhu University

In this study, a human-sensitive frequency band vibration isolator(HFBVI)with quasi-zero stiffness(QZS) characteristics for heavy-duty truck seats is designed to improve the comfort of heavy-duty truck drivers on uneven roads. First, the analytical expressions for the force and displacement of the HFBVI are derived with the Lagrange equation and d'Alembert's principle, and are validated through the prototype restoring force testing. Second, the harmonic balance method(HBM) is used to obtain the dynamic responses under harmonic excitation, and further the influence of pre-stretching on the dynamic characteristics and transmissibility is discussed. Finally, the experimental prototype of the HFBVI is fabricated, and vibration experiments are conducted under harmonic excitation to verify the vibration isolation performance(VIP) of the proposed vibration isolator. The experimental results indicate that the HFBVI can effectively suppress the frequency band(4–8 Hz) to which the human body is sensitive to vertical vibration. In addition, under real random road spectrum excitation, the HFBVI can achieve low-frequency vibration isolation close to 2 Hz, providing new prospects for ensuring the health of heavy-duty truck drivers.

关键词： human-sensitive frequency band quasi-zero stiffness (QZS) heavy-duty truck seat real random road spectrum low-frequency vibration isolation O328 ISOLATION SYSTEM DESIGN

THE VOF METHOD FOR STUDY OF WAVE RUN-UP AND BREAKING ON A SLOPING STRUCTURE

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Journal of Hydrodynamics 1997年第4期9卷 88-96页

作者： Wan De-chengshanghai institute of applied mathematics, and mechanics shanghai university,shanghai200072, P. R. china.Miao Guo-pingDepartment of Naval Architecture and Ocean Engineering, shanghai Jiao Tong university,shanghai 200030,P. R. china.dai shi-qiangshanghai institute of applied mathematics and mechanics, shanghai university,shanghai200072, P. R. china.

The volume of fluid method (VOF method) for numerical simulations describing wave run-up on a sloping structure including the overturning. breaking and merging phenomena is presented. The flow motions are governed by the classical, two-dimensional Navier-Stokes equation for incompressible fluid. Computational results concerning the time evolution of the free surface and pressure distribution along water bed and slope boundary are given, showing how an initial solitary wave undergoes run-up, overturning, breaking and merging on the slope. It is found that most of the wave energy is lost after the wave breaking and merging.

关键词： VOF method wave run-up wave breaking sloping structure

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关于振荡型的界面孤立波

水动力学研究与进展（A辑） 1992年第1期7卷 1-6页

作者：戴世强上海工业大学上海市应用数学和力学研究所上海200072

当计及表面张力时,对于二流体系统中两层流体深度比的一种临界情形,界面孤立波可用推广的KdV方程来描述,这一方程难以解析地求出孤立波解。本文采用作者提出的推广的PLK方法求得了三阶近似孤立波解,并采用Lindstedt-Poincare方法对所得... 详细信息

当计及表面张力时,对于二流体系统中两层流体深度比的一种临界情形,界面孤立波可用推广的KdV方程来描述,这一方程难以解析地求出孤立波解。本文采用作者提出的推广的PLK方法求得了三阶近似孤立波解,并采用Lindstedt-Poincare方法对所得的结果作了验证,从而首次解析地证实了振荡型界面孤立波的存在性。

关键词：二流体系统界面波孤立波 PLK法

Stabilization of traffic flow in an extended car following model

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Stabilization of traffic flow in an extended car following m...

有限深水中骑行波的显式Hamilton描述

第十八届全国水动力学研讨会

作者： ge hong-xia dai shi-qiang Dong Li-yun Meng Qing-xun shanghai institute of applied mathematics and mechanics, shanghai university, shanghai 200072

＜正＞An extended car following model was proposed by incorporating a cooperative driving system. The stability condition of the model was obtained using the linear stability theory. The results show that considering more than one vehicle ahead leads to stabilization of the system. The modified Korteweg-de Vries equation （the mKdV equation, for short） near the critical point was derived by using the reductive perturbation method. The traffic jam was proved to be described by kink-anti-kink solution obtained from the mKdV equation.

关键词： traffic flow phase transition modified KdV equation (mKdV equation) car following model

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力学季刊 2002年第3期23卷 331-336页

作者：安淑萍乐嘉春戴世强上海市应用数学和力学研究所上海大学上海200072

小尺度波(扰动波)迭加在大尺度波(未受扰动波)上形成的波动一般称之为“骑行波”。研究了有限可变深度的理想不可压缩流体中的骑行波的显式Hamilton表示,考虑了自由面上流体与空气之间的表面张力。采用自由面高度和自由面上速度势构成的... 详细信息

小尺度波(扰动波)迭加在大尺度波(未受扰动波)上形成的波动一般称之为“骑行波”。研究了有限可变深度的理想不可压缩流体中的骑行波的显式Hamilton表示,考虑了自由面上流体与空气之间的表面张力。采用自由面高度和自由面上速度势构成的Hamilton正则变量表示骑行波的动能密度,并在未受扰动波的自由面上作一阶展开。运用复变函数论方法处理了二维流动。先用保角变换将物理平面上的流动区域交换到复势平面上的无限长带形区域,然后在复势平面上用Fourier变换解出Laplace方程,最后经Fourier逆变换求出了扰动波速度势所满足的积分方程。作为特例考虑了平坦底部的流动,导出了动能密度的显式表达式。这里给出的积分方程可以替代相当难解的Hamilton正则方程。通过求解积分方程可得出Lagrange密度的显式表达式。本文提出的方法为研究骑行波的Hamilton描述以及波的相互作用问题提供了新的途径,有助于了解海面的小尺度波的精细结构。

关键词：显式Hamilton 表面波有限深水骑行波不可压缩流体动能密度小尺度波海洋动力学