风杯式风速传感器启动风速校准方法及实验箱设计

发布时间：2018-02-09 15:23

  本文关键词： 风杯式风速传感器 启动风速 校准方法 实验箱 数值仿真　出处：《南京信息工程大学》2016年硕士论文　论文类型：学位论文

【摘要】：测风仪器中使用最为广泛的是风杯式风速计,但由于长期在户外使用,受各种天气因素影响,风杯组件老化,启动风速增大,传统校准启动风速的方法是将其送到专业风洞实验室进行校准,费事费力,达不到现场校准的目的,因此,需采用新的方法对启动风速进行现场校准。本文针对风杯式风速传感器启动风速现场校准的问题,分析了启动风速影响因素,推导了启动风速公式,对影响因素中的风压系数进行拟合,提出了可以现场测量启动风速的方法,设计了启动风速校准实验箱；实验箱设计主要包括两部分工作,一是实验箱结构设计部分,二是实验箱硬件电路设计部分。实验箱结构设计是本文的主体部分及难点,在采用有限元方法进行实验箱结构设计前,研究了计算流体动力学基础理论,主要包括：三种基本控制方程,讨论常用湍流模型,说明本仿真分析选取S-A湍流模型原因,并确定湍流模型的仿真参数；阐述对CFD仿真具有关键作用的网格划分,说明本仿真选取非结构化网格原因,详细论述CFD工作流程,确定本仿真实验的具体过程。实验箱结构设计中,利用三维CAD软件建立多种实验箱结构模型,选取合适湍流模型、计算模型及仿真参数,采用有限元软件fluent进行大量数值仿真实验,对求解结果进行可视化处理,对比分析结构不同的风扇动力段,整流段,收缩段对实验箱内流场形态的影响,选取合适结构,在不同风扇转速下对稳定出口段流场形态进行研究,并同时考察整体实验箱流场形态。实验箱硬件电路设计包括：风扇动力段采用PWM直流电机调速,检测风速计是否启动的光电控制开关,以及对实验箱稳定出口段风速实时测量的闭环恒温式热线测风速部分,介绍了各部分的工作原理,给出硬件电路原理图。总结实验箱各部分设计,实验箱整体结构仿真分析结果表明：实验箱出口段流场形态及速度稳定,满足校准要求,硬件电路功能完整,可以达到现场校准的目的。
[Abstract]:The wind-cup anemometer is the most widely used in the wind measuring instrument. However, due to the long-term outdoor use and the influence of various weather factors, the wind cup component is aging and the starting wind speed is increasing. The traditional method of calibrating start-up wind speed is to send it to the professional wind tunnel laboratory for calibration. A new method is needed to calibrate the starting wind speed. In this paper, the factors influencing the starting wind speed are analyzed, and the formula of the starting wind speed is deduced, aiming at the problem of the field calibration of the starting wind speed of the wind speed sensor. By fitting the wind pressure coefficient of the influencing factors, the method of measuring the starting wind speed on the spot is put forward, and the test box for the calibration of the starting wind speed is designed. The design of the experimental box mainly includes two parts, one is the structural design of the experimental box, and the other is the design of the structure of the experimental box. The second part is the hardware circuit design of the experimental box. The structure design of the experimental box is the main part and the difficulty of this paper. Before adopting the finite element method to design the experimental box structure, the basic theory of computational fluid dynamics (CFD) is studied. It mainly includes three kinds of basic control equations, discusses the common turbulence models, explains why S-A turbulence model is selected in the simulation analysis, and determines the simulation parameters of the turbulence model, and expounds the grid division which plays a key role in the CFD simulation. The reason why unstructured grid is selected in this simulation is explained, the working flow of CFD is discussed in detail, and the concrete process of this simulation experiment is determined. In the structural design of experimental box, many kinds of structural models of experimental box are established by using 3D CAD software, and appropriate turbulence model is selected. In order to calculate the model and the simulation parameters, the finite element software fluent is used to carry out a large number of numerical simulation experiments, and the results are visualized, and the effects of the fan power segment, rectifier section and contraction section of different structure on the flow field in the experimental box are compared and analyzed. At the same time, the flow field pattern of the whole experimental box is investigated. The hardware circuit design of the experimental box includes: the fan power section is regulated by PWM DC motor. The photoelectric control switch for detecting whether the anemometer is started, and the closed loop constant temperature hot-wire wind speed measuring part for the real time measurement of the wind speed at the stable exit section of the experimental box are introduced. The working principle of each part is introduced. The schematic diagram of the hardware circuit is given. The design of each part of the experimental box is summarized. The simulation results of the whole structure of the experimental box show that the flow field form and velocity of the outlet section of the experimental box are stable, the calibration requirements are satisfied, and the function of the hardware circuit is complete. The purpose of field calibration can be achieved.
【学位授予单位】：南京信息工程大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：P414.7;TP212
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本文编号：1498241