液滴冲击流动液膜的格子Boltzmann模拟

采用单相格子Boltzmann方法模拟了二维液滴冲击流动液膜的含自由面的流动过程。由定义的质量与密度的比例系数来追踪气液自由面的变化。表面张力通过计算界面格点处作用在流体上的汽液相间作用力加入到模型中。数值模拟了速度比(液膜流动速度与液滴撞击速度的比值)和液膜相对厚度(液膜实际厚度与液滴直径的比值)不同时,液滴冲击流动液膜的过程。与液滴冲击静止液膜时的计算结果和理论分析结果进行对比,分析了液滴冲击流动液膜后产生的流动现象及其内在机理,产生的水花的铺展半径和溅起高度随时间的变化规律,并讨论了飞溅产生条件。     

水泵吸水管和进水池内三维湍流的数值模拟

建立了泵站中水泵吸水管和进水池内部三维湍流流场的数学模型,针对泵站中布置了多台机组的多个吸水管和进水池中三维流场的计算边界条件作了深入分析,提出了合理的边界条件。根据分区划分网格的思想,构造了任意形状的水泵吸水管和进水池的贴体计算网格,在任意坐标系中对三维湍流流场的控制方程进行离散,编制了水泵吸水管和进水池内部三维湍流流场数值模拟的计算程序。数值模拟计算了泵站中水泵吸水管和进水池内部三维湍流流场。在数值模拟基础上,可对泵站中水泵吸水管和进水池内部流态进行评估。     

马路坪矿深部红页岩底鼓形成机理研究

针对马路坪矿深部红页岩巷道底板出现的底鼓问题,对深部软岩巷道的底鼓成因和机理进行了分析,从而得出随着巷道掘进深度的增加,巷道底板弹性区的应力增长梯度及其静水压力增长梯度呈线性关系,与巷道底板的塑性区呈现近似线性相关关系,研究结果为马路坪矿探部红页岩软岩巷道底鼓的防治提供了理论依据.     

Numerical research on the mechanism of contaminant release through the porous sediment-overlying water interface

After the pollutant discharged into the river or lake has been reduced, the release of the contaminant from the sediment to the overlying water may cause the river and lake be contaminated again. On the condition that the overlying water flow does not lead to sediment suspension, numerical researches are carried out for the mechanism of contaminant release through the sedimentoverlying water interface. The overlying water flow is calculated as turbulence. The sediment is regarded as isotropic homogeneous porous medium, therefore the seepage field in the porous sediment layer is obtained by solving Darcy＇s equations. Coupled two dimensional steady flows of the overlying water and the pore water in the sediment are calculated. Based on the flow fields obtained, the unsteady contaminant solute transportation process in the pore water in the sediment and the overlying water is numerically simulated, as the shapes of the sediment-overlying water interface are flat or periodic triangular respectively. Numerical results show that the exchange of the pore water and the overlying water is an important factor which decides the release flux of the contaminant from the sediment to the overlying water. The pressure distribution produced by the overlying water flow along the sedimentoverlying water interface, as it is not flat, may induce the seepage of the pore water in the sediment and through the sedimentoverlying water interface, which may increase the release flux of the contaminant from the sediment to the overlying water.     

液压水闸纠偏运行的计算机监控系统设计

本文提出了水闸纠偏运行的计算机监控系统的设计方案；根据液压水闸升降运行特点和偏差控制要求，建立了液压水闸纠偏运行的控制原理和模式；根据液压水闸液压系统的结构组成和运行方式，运用液压流体力学分析方法，建立了闸门液压系统安全运行的控制要求和模式；系统整体结构设计采用开放式分层分布计算机系统，系统整体性能优越．能精确、快速、安全地完成闸门纠偏运行计算机监控的各项要求．     

Parametric instability of a liquid metal sessile drop under the action of low-frequency alternating magnetic fields

A 2-D mathematical model is developed in order to simulate a parametric electromagnetic instability oscillation process of a liquid metal droplet under the action of low frequency magnetic field. The Arbitrary Lagrangian-Eulerian (ALE) method and weak form constraint boundary condition are introduced in this model for implementation of the surface tension and electromagnetic force on liquid droplet free surface. The results of the numerical calculations indicate the appearance of various regimes of oscillation. It is found that according to the magnetic field frequency various types of oscillation modes may be found. The oscillation is originated from an instability phenomenon. The stability diagram of liquid metal droplet in the parameter space of magnetic frequency and magnetic flux density is determined numerically. The diagram is very similar to that found in the so-called parametric instability.     

吸水口前自由表面旋涡的LBM模拟

作者采用单相自由面格子Boltzmann模型,数值模拟了水槽底部吸水装置在科氏力诱导下自由表面旋涡的生成和演化过程。计算结果表明本文采用的方法能够较好地捕捉自由表面旋涡流动的大幅度变化的气液两相界面,同时通过对自由表面旋涡生成与演化过程中不同水平面的速度矢量分布,切向速度、径向速度、环量以及涡核半径的变化规律的分析,说明计算结果与实验结果是一致的。     

格子Boltzmann方法模拟双液滴同时冲击固体表面液膜

采用单相自由面格子Boltzmann方法数值模拟了两个液滴撞击同种薄膜的流动过程。计算格子的液体比例系数来追踪气液界面的形状,表面张力效应通过分布函数的重构来引入。数值模拟中分别考虑了液滴以不同速度、不同中心间距撞击液膜的情况。数值计算了两个液滴同时撞击液膜产生水花、发生飞溅,水花相遇并发生碰撞后的流动现象。分析了液滴冲击速度及其水平距离对上述流动现象的影响。     

斜流泵轴向推力的数值计算

对斜流泵叶轮内部流动进行了数值解析 ,翼面和轮毂表面的压力分布 ,数值计算开放型斜流泵的轴向推力 ,所得结果与试验值对比基本吻合     

周期性振荡湍流的壁函数研究和数值实验

目前二阶湍流模式已被广泛运用于湍流的计算中，壁面和主湍流之的近壁区通常采用壁函数来近似计算，目前常采用的壁函数基于流动准稳态和充分发展等条件，对于周期性振荡湍流这类非定常湍流已不适应。本文基于周期性振荡湍流条件。推导了适用于周期性振荡湍流条件的近壁函数。采用Ｋ－ε模式，结合本文推导的周期性振荡湍流近壁函数，计算了一个二维直管周期振荡湍流流场，计算结果表明用本文推导的周期性振荡湍流近壁函数所得结果与