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两相流是自然界最广泛存在的流态之一 ， 在工业生产和日常生活中有着重要的作用。然而 ， 两相流系统是一个复杂的非线性动态系统 ， 相间存在界面效应和相对速度 ， 检测难度较大。两相流参数的实时准确测量成为工程和科研领域尚未得到有效解决的问题。两相流的测量方法有很多 , 其中的电阻层析成像技术 (Electrical Resistnaec Tomgoarphy, 简称 ERT) 通过测量敏感场内电导率变化 , 得到对象的流动特性 , 具有非侵入 , 无辐射 , 可视化等特点 , 在工业过程中有广泛的应用前景。本文设计了一套基于 FPGA 的 ERT 电阻率测量系统并 采用相邻电流激励 ， 相邻电压测量的四电极测量电阻的方式，采用 幅值恒定的双极性电流信号作为激励信号。本课题中完成的工作如下：1. 总结了 ERT 技术的发展过程及研究现状。了解了电阻率测量系统的总体设计及工作原理，各模块实现的功能。2. 设计并实现基于 FPGA 的气液两相流的电阻率测量系统 ，设 计 编写了驱动程序，程序包括按键消抖模块，直流电流与交流电流变换模块 , 电极切换模块 ， 程控放大模块 ， 串口发送模块 ， AD 转换模块 。 详细介绍了电阻率测量系统各软件模块设计。3. 设计了基于 LabVIEW 的 ERT 测量系统上位机软件。 上位机实现数据的采集，并对数据进行实时显示，以便观测数据59930
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毕业论文关键词： 两相流 电阻率测量系统 FPGA LabVIEW
Title Gas-liquid two-phase flow resistivity measurementsystem design-the software partAbstract Abstract Abstract AbstractT he two-phase flow is one of nature's most widespread flow pattern playsan important role in industrial production and daily life . However, thetwo-phase flow system is a complex nonlinear dynamic system , and whiteinterface effect and the relative velocity detection difficult .Real-timeand accurate measurement of two-phase flow parameters become the field ofengineering and scientific research has not yet been an effective solutionto the problem .Many methods have been applied on measuring two 一 phase flow the one withgreat perspective is Electrical Resistance Tomography(ERT) which canobtain the flow characteristic of two-Phase flow by measuring the changeof the conductivity in the sensing field that estbalished by injectingexciting current into measured cross-section.The characteristic of thistechnique is non-intursive,non 一 radiant,visualization and etc.This paper designs a set of FPGA-based ERT resistivity measurement systems and usesthe adjacent current excitation , adjacent four-electrode voltagemeasurement measuring resistance , the use of constant amplitude bipolarcurrent signal as the excitation signal .The work done in this topic are as follows:1 ． summarizes the the ERT technology development process and researchstatus . Understand the resistance tomography system design and operatingprinciple of the function of each module .2. design and implement resistivity measurement system based on FPGA gas-liquid two-phase flow, specially designed for the driver, the programincludes the key debounce modules, DC current, AC current transformationmodule, the electrode switching module, program-controlled amplifiermodule, serial port to sendmodule, AD conversion module. Details of theresistivity measurement system software module design.3. Designed PC software the ERT measurement system based on LabVIEW . Hostcomputer for data collection , and the data is displayed in real time inorder to monitor data
Keywords: The two-phase flow resistivity measurement systemFPGA LabVIEW
目 录
1 绪论 1
1.1 课题的研究背景及意义 1
1.2 ERT 应用系统设计的国内外研究的发展概况 . 3
1.3 课题的研究内容 .. 6
1.4 论文结构 .. 6
2 ERT 系统的硬件结构介绍 . 8
2.1 ERT 系统的原理及组成 . 8