Electric field distribution in 75 kA drained aluminum reduction cell

Current distribution in a drained aluminum reduction cell is critical due to its influence on the current efficiency, electrolysis stability, anodes and cathodes integrity. A finite element model was developed to simulate the electric field in a 75 kA drained aluminum reduction cell. The current distribution and influences of the cathode inclination angle and anode-cathode distance (ACD) were studied. The results show that relatively large horizontal current density appears in the aluminum film, and the max...     

Numerical simulation on electrolyte flow field in 156 kA drained aluminum reduction cells

Based on the commercial CFD software CFX-4.3, two-phase flow of electrolyte in 156 kA drained aluminum reduction cells with a new structure was numerically simulated by multi-fluid model and k-ε turbulence model. The results show that the electrolyte flow in the drained cells is more even than in the conventional cells. Corresponding to center point feeding, the electrolyte flow in the drained cells is more advantageous to the release of anode gas, the dissolution and diffusion of alumina, and the gradient reduction of the electrolyte density and temperature. The average velocity of the electrolyte is 8.3 cm/s, and the maximum velocity is 59.5 cm/s. The average and maximum velocities of the gas are 23.2 cm/s and 61.1 cm/s, respectively. The cathode drained slope and anode cathode distance have certain effects on the electrolyte flow.     

稀土氧化物电解槽电场的计算机模拟

建立了稀土氧化物电解槽电场计算的数学模型,并采用有限差分方法对电解槽的电场进行了计算机模拟,为电解槽的设计提供了理论依据。     

微机自适应控制系统及其应用实例

介绍无需人参与的微机自适应控制系统的组成和运作过程，并以硅铁炉为例从硬件和软件两个方面详细叙述实现这一控制方案的方法。     

Alternating electric field actuated oscillating behavior of liquid metal and its application

As a class of newly emerging functional material, Gallium based liquid metals have attracted increasing attentions in many fields, such as chip cooling, printed electronics and microfluidics, etc. Particularly, the motion control of liquid metal droplet has been recently tried for its importance in microelectromechanical system (MEMS), microfluidics and potential use in micro-machine or reconfigurable soft robot. This paper is dedicated to explore the motion behavior of liquid metal droplet under AC electric field. The quickly induced oscillation phenomena of liquid metal droplet and surrounding electrolyte solution were observed and the major factors to influence such behaviors are theoretically interpreted and experimentally investigated, including the size of the liquid metal droplet, electrode voltage, electrolyte solution concentration and AC signal frequency etc. Moreover, some typical features to distinguish AC filed actuation with DC field are observed, such as intensive fluid waving induced by the resonance stimulation, and the efficient inhibition of solution electrolysis. Finally, two important applications of adopting AC induced surface oscillation of liquid metal droplet to develop solution mixer as well as fluidic pump were demonstrated which successfully avoid gas generation inside electrolyte environment. The bulk oscillation effects of liquid metal as clarified here could be very useful in a variety of areas such as solution disturbance and mixing, and fluid oscillator or pump etc.     

基于两相流动的铝电解槽磁流体流场数值仿真

为了对铝电解槽内磁流体的两相流动和界面波动进行深入了解,通过ANSYS和CFX相结合的方法,把洛伦兹力作为动量源相,对160kA铝电解槽内的磁流体流动进行了两相流数值仿真.仿真结果表明：铝液和电解质的流动均呈两个漩涡;铝液的平均流速为0.1476m/s,最大流速为0.2879m/s;电解质的流速偏小,平均流速为0.1165m/s,最大流速为0.286.6m/s;电解质和铝液的界面变形范围为-0.029~0.035m.将流速计算结果与实测值进行了对比,表明对基于两相流动的铝电解槽内磁流体进行数值仿真可以帮助了解铝电解槽内的流场,为进一步优化研究提供了依据.     

智能预焙铝电解槽系统的硬件软件实现

铝电解是迄今规模最大的熔盐电解工业.首先介绍了电解槽硬件电路的整体实现,系统包括数字电路和模拟电路2种方案,以保证系统能够连续运行和软件设计的整体思路.然后介绍了各个模块的具体实现和软件设计.最后介绍了系统的抗干扰设计,提高了系统的稳定性和可靠性.     

遗传算法及其应用

介绍了遗传算法的定义,内容,及其应用.重点介绍了遗传算法中数字图像的目标函数的确定,以确保图像的保真.介绍了选择、交换、变异算子在遗传算法中的应用.展望了遗传算法在各行业的应用.     

渐开线齿轮廓线生成动态仿真及其应用

渐开线齿轮廓线难以精确绘制,尤其是存在齿根过渡曲线变化较大的问题。为此,提出一种基于VBA和AutoCAD ActiveX技术的动态模拟齿轮加工方法,通过动态绘制齿轮坯与齿条刀具问的相对位置,形象演示齿轮渐开线和齿根过渡线的形成过程。用动态模拟的方法得到的齿轮廓线精确度高,可直接用于齿轮三维的精确造型。     

双转子电机及其在混合电动汽车中的应用

双转子电机相对于传统电机,增加了一个旋转部件,可实现两路机械能量的独立传递,不仅具有更高的功率密度和效率,而且可实现多动力源机电能量耦合输出,应用于混合动力汽车驱动系统中,通过内外电机的协调控制使发动机工作在最佳效率区,实现多种工作模式和无级变速,具有广泛的工业应用前景.介绍了双转子电机的发展,分析了几种主要类型双转子电机结构、工作原理及其在混合电动汽车驱动系统的应用特点,并针对其结构设计、系统控制等方面的技术难点和现有不足,探讨了双转子电机及其混合电动汽车领域应用的发展趋势和研究方向.     

喷射流场及其辐射声场数值模拟

为研究喷管结构对射流噪声的影响,采用大涡模拟对不同截面形状喷口形成的非定常湍射流场进行了数值模拟.在流场计算的基础上,结合Ffowcs Williams-Hawkings积分方程对远场声场进行了计算,得到不同喷管结构对应的湍射流场的流动结构及其辐射噪声的频谱特性.计算结果表明,椭圆形截面喷管的出口附近存在大量的旋涡结构,增大了射流边界层处的气流掺混,从而降低了射流核心区的长度,有效抑制了喷射噪声,在5种不同结构的喷管中,椭圆形截面的喷管对应的辐射声压最低,而矩形喷管对应的辐射声压最高;在射流方向的30°～75°扇形区域内,辐射声信号最强且存在明显的指向性.     

N×N无规随机网络电阻的改进算法及仿真

针对现有无规电阻的近似计算模型提出了改进的方法并且在此基础上进行了仿真验证,在通过实验方法得到了等效电阻值下,通过数理统计假设检验的方法比较了实验数据和计算数据,结果很好地说明了改进模型计算的精确性和可行性,这对实际生产有一定的积极作用.     

Improved PSO algorithm and its application

The mechanism of particle swarm optimization algorithm is studied, and one can draw the conclusion that the best particle found by the swarm falling into local minima is one of the main reasons for premature convergence. Therefore, an improved particle swarm optimization algorithm is proposed. This algorithm selects the best particle with roulette wheel selection method, so premature converging to local optima is avoided. At last, the improved particle swarm optimization algorithm is applied to optimization of time-sharing power supply for zinc electrolytic process. Simulation and practical results show that the global search ability of IPSO is improved greatly and optimization of time-sharing power supply for zinc electrolytic process can bring about outstanding economic benefit for plant.     

Improved PSO algorithm and its application

The mechanism of particle swarm optimization algorithm is studied, and one can draw the conclusion that the best particle found by the swarm falling into local minima is one of the main reasons for premature convergence. Therefore, an improved particle swarm optimization algorithm is proposed. This algorithm selects the best particle with roulette wheel selection method, so premature converging to local optima is avoided. At last, the improved particle swarm optimization algorithm is applied to optimization of time-sharing power supply for zinc electrolytic process. Simulation and practical results show that the global search ability of IPSO is improved greatly and optimization of time-sharing power supply for zinc electrolytic process can bring about outstanding economic benefit for plant. Foundation item: Project (2002CB312200) supported by the National Key Research 973 Program of China     

近似RLS算法及其应用

本文提出了一种新的自适应均衡算法——近似RLS算法,并把该算法应用于短波信道、判决反馈均衡器。分析和计算机模拟表明:近似RLS算法在收敛性能上近似于RLS算法,在计算效率和稳定性方面性能优于RLS算法。总之,该算法是一种简单而实用的自适应均衡算法。     

自适应蚁群算法及其在边坡工程中的应用

蚁群算法目前多用于求解组合优化问题，为了让蚁群算法能求解复杂的边坡稳定性分析问题，对基本蚁群算法的结构形式和蚂蚁转移概率的计算进行了改进，针对蚁群算法在演化过程中存在停滞和过早收敛的现象，引入一种自适应搜索算子，改变蚂蚁的选择机制，提高蚂蚁选择的多样性，并由此构建了一种新的蚁群算法——自适应蚁群算法(AACA)，研究了AACA在边坡非圆弧临界滑动面搜索中的应用，所给出的算例结果表明：与基本蚁群算法相比，可有效地防止停滞和过早收敛现象，并总能搜索到问题的全局最优解，且搜索效率也有较大的提高。     

Modified electromagnetism-like algorithm and its application to slope stability analysis

In the view of the disadvantages of complex method (CM) and electromagnetism-like algorithm (EM), complex electromagnetism-like hybrid algorithm (CEM) was proposed by embedding complex method into electromagnetism-like algorithm as local optimization algorithm. CEM was adopted to search the minimum safety factor in slope stability analysis and the results show that CEM holds advantages over EM and CM. It combines the merits of two and is more stable and efficient. For further improvement, two CEM hybrid algorithms based on predatory search (PS) strategies were proposed, both of which consist of modified algorithms and the search area of which is dynamically adjusted by changing restriction. The CEM-PS1 adopts theoretical framework of original predatory search strategy. The CEM-PS2 employs the idea of area-restricted search learned from predatory search strategy, but the algorithm structure is simpler. Both the CEM-PS1 and CEM-PS2 have been demonstrated more effective and efficient than the others. As for complex method which locates in hybrid algorithm, the optimization can be achieved at a convergence precision of 1×10⁻³, which is recommended to use.     

电性拓扑指数m D及其应用

构建了电性拓扑指数^mD．用^mD的0、1阶指数分别与16种碱金属卤化物的熔点Tmp、磁化率Xm、键长Bd、20种碱金属卤化物的晶格能U1、20种碱土金属卤化物的晶格能U2、19种金属氧化物、硫化物和氟化物的晶格能U3和80种离子标准生成热△fHm^θ关联,拟合的回归方程的相关系数(复相关系数)分别为0．9445、-0．9873、-0．9914、0．9972(0．9973)、0．9839(0．9881)、0．9952(0．9955)和0．9780,基本上满足优级或良级标准．预测取得较好的结果．     

基于神经元自适应调节的液压伺服系统滑模变结构控制

基于滑模特点和神经元的学习特性 ,提出一种基于神经元自适应调节的滑模变结构控制策略 ,并把它应用于一液压非线性伺服系统的位置控制 .仿真实验结果表明 ,所提出的控制策略可行 ,对进一步改善滑模变结构控制系统的动态特性和鲁棒性 ,以及削弱滑模控制抖振现象具有明显积极作用 ,是一种有效的控制方法