复合形法在法兰支承液压缸优化设计中的应用

针对目前液压缸结构设计中主要结构参数依据经验方法确定的不足,基于复合形法编制了结构优化设计软件,并用此软件对某型号法兰支承液压缸进行了优化设计。结果表明,采用该结构优化设计软件优化后的液压缸重量相对减少了很多,优化效果明显。     

小波包特征熵神经网络在尾水管故障诊断中的应用

为精确诊断水轮机尾水管涡带，该文提出一种基于小波包特征熵的神经网络故障诊断新方法。对采集到的尾水管压力脉动信号进行三层小波包分解，提取小波包特征熵，然后构造信号的小波包特征熵向量，并以此向量作为故障样本对三层BP神经网络进行训练，实现智能化故障诊断。试验结果表明训练成功的BP网络能够很好地诊断机组尾水管是否发生涡带以及涡带的严重程度，为水轮机故障诊断开辟新的途径。     

混流式水轮机过渡过程数值模型研制

文章给出了作者所采用的水轮机综合特性曲线的数值化工作的基本原理及几个实例,并就作者建立的一维管道瞬态流计算,混流式水轮机调保计算,以及小波动过程的动态模拟等程序的工作原理和功能进行了介绍,还提供了几个计算结果作为例证。     

液压机工况显示的总线复用

以总线复用思想为指导 ,结合PLC的工作特点 ,论述了动态显示的软硬件设计方法 ,并用较大篇幅对软件设计技巧进行了探讨。     

Numerical simulation and analysis of power consumption and Metzner-Otto constant for impeller of 6PBT

Majority of non-Newtonian fluids are pseudoplastic with shear-thinning property, which means that the viscosity will be different in different parts of the stirred tank. In such mixing process, it is difficult to predict accurately the power consumption and mean shear rate for designing novel impeller. Metzner-Otto method is a widely accepted method to solve these questions in mixing non-Newtonian fluids. As a result, Metzner-Otto constant will become a key factor to achieve an optimum way of economical mixing. In this paper, taking glycerine and xanthan gum solutions as research system, the power consumption, stirred by the impeller composed of perturbed six-bent-bladed turbine （6PBT） with differently geometrical characteristics in a cylindrical vessel, is studied by means of computational fluid dynamics （CFD）. The flow is modeled as laminar and a multiple reference frame （MRF） approach is used to solve the discretized equations of motion. In order to determine the capability of CFD to forecast the flow process, the torque test experiment is used to measure the glycerine solution power consumption. The theological properties of the xanthan gum solutions are determined by a Brookfleld rheometer. It is observed that the power consumption predicted by numerical simulation agrees well with those measured using torque experiment method in stirring glycerine solution, which validate the numerical model. Metzner-Otto constant is almost not correlated with the flow behavior index of pseudoplastic fluids. This paper establishes the complete correlations of power constant and Metzner-Otto constant with impeller geometrical characteristics through linear regression analysis, which provides the valuable instructions and references for accurately predicting the power consumption and mean shear rate of pseudoplastic fluids in laminar flow, comparatively.