基于LabVIEW的互相关流速.docVIP

基于LabVIEW的互相关流速测量系统的设计 摘 要 两相流在自然界和工业过程中是普遍存在的，其中离散相的运动速度、尺寸、位置等参数的监测是一个非常重要的测量研究课题。 两相流相关测速系统主要由上、下游传感器把流动噪声信号的变化转化为电信号的变化，然后通过放大，滤波，A/D转换电路将数字信号送到互相关器处理，最后输出渡越时间，进行流速的计算。 本设计采用虚拟仪器技术和互相关原理相结合，设计了互相关流体流速测量仪。该方法利用了上、下游流动噪声信号的相关性，通过求两通道中信号与信号的互相关函数，得到两个信号的时延，在已知两传感器间距L的情况下，知道两个信号的时延可以求出流体的流速。设计中用LabVIEW语言编制程序，模拟生成随机流动噪声信号，将数据送入数据采集卡中，之后再将数据采集出来做各种相关运算。本设计阐述了基于虚拟仪器技术和互相关原理流体流速测量仪的实现过程，给出了使用LabVIEW语言的核心程序，并对结果误差进行了分析。 关键词：两相流；互相关；虚拟仪器；流速测量 The System of Cross-correlation Velocity Measurement Base on LabVIEW Abstract The two-phase flow is widespread in nature and industrial processes.The measurement of parameters of multiphase flow，such as velocity，size and position of bubbles is a very important investigation subject. Two-phase cross-correlation flow velocity measurement system changes the flow noise signal into electrical signal by the upper and under sensors，through the amplification，filtering，A/D converter circuit，and the digital signal will be sent cross correlator.Finally output is the transit time and the velocity. This systemic designed to inter-related fluid flow measuring instrument virtual instrument technology and the principle of combining cross-correlation.This method got delay of two signals by cross-correlation function between two signals.The fluid flow can be exceed by the delay value of the two signal in case of the distance of L between two sensors is known.System carry the data which is a random noise signal simulation by LabVIEW，and then acquisition the data to various computing.This system shows fluid flow rate measuring instrument achieve process based on LabVIEW and Cross-correlation which shows core procedures of LabVIEW and analysed the error of the result. Key words：two-phase flow；cross-correlation；virtual instrument；velocity measurement 摘 要 I Abstract II 第一章 引言 1 1.1两相流测量的应用背景 1 1.2我国流量仪表的发展及现状 1 1.2.1概述 1 1.2.2我国流量仪表的发展回顾 2 1.2.3流量仪表总体的技术发展方向 3 1.2.4对流量测量技术的展望 3 第二章 相关流量测量技术 4 2.1相关流量测量技术简介 4 2.2相关测量技术的发展简史 4 2.3互相关知识简介 5 2.3.1测量原理 5 2.3.