基于LDV的雨水管道流速检测的应用研究

Application of Laser Doppler Velocity in Velocity Measurement of Rainwater in Pipe

在分析雨水管道复杂流体成分的基础上,提出利用管道内的固体颗粒作为示踪粒子,采用激光多普勒测速的方法对管道流体进行速度测量。为了验证应用的合理性,根据条纹模型和散射机理建立了雨水管道内流体LDV的数学模型,并通过数值模拟,分析了雨水管道流体中示踪粒子和速度测量精度之间的关系。然后对模拟的信号进行时频分析,得到雨水管道中的流速。通过实验验证,实际效果和数值模拟结果符合良好,说明LDV能够精确地测量出雨水管道中的流体速度。

After analyzed the complex composition of fluid in the rain pipes, this paper uses solid particles within the existing pipe as the tracer particles, to measure the speed of the pipeline fluid using laser Doppler velocity method. In order to verify the feasibility of this method, in this paper, based on a theoretic model of fringes and the principle of light interfering and scattering, a mathematic model of LDV for tracer particles has been developed and we analyzes the relationship between the characteristics of the tracer particles and the measurement accuracy for velocity of the fluid in the rain pipes through computer simulation in details. Finally analog signals with time-frequency analysis method, we get the Velocity of Rainwater in Pipe. The results of experiment accord with the results of simulation exactly, the analysis leads to the conclusion that LDV system can measure precisely the speed of moving fluid after using our methord.