Allafchi Farzam, Valeo Caterina, Chu Angus, He Jianxun, Lee Waltfred, Oshkai Peter, Neumann Norman
Mechanical Engineering Department, University of Victoria, Victoria, BC V8W 2Y2, Canada.
Department of Civil Engineering, Schulich School of Engineering, University of Calgary, Calgary, AB T2N 1N4, Canada.
Sensors (Basel). 2020 Dec 16;20(24):7204. doi: 10.3390/s20247204.
A velocity meter was designed and built in order to meet market needs for an affordable instrument that measures the range of velocity magnitudes and direction experienced in medium- to large-sized water bodies. The velocity meter consists of a graduated plate with an injector protruding from the center and a camera held downward above the plate. Once the Dye Injection Velocity (DIV) meter is in the flow, dye is injected and the camera records the dye fluid transport. The recorded video is analyzed to determine the local flow velocity and direction. The DIV was calibrated for a range of velocities between 0.0094 m/s and 0.1566 m/s using particle image velocimetry (PIV) in a flow visualization flume. The accuracy of the instrument was found to be +6.3% and -9.8% of full scale. The coefficient of determination of the calibration curve was equal to 98%. Once calibrated, the DIV was deployed to the Inverness Stormwater pond in Calgary, Canada, for validation tests against an Acoustic Doppler Velocity (ADV) meter. During the validation tests, both flow velocity magnitude and direction were measured at several spatial points. The velocity magnitude results showed good agreement and the Mann-Whitney test showed no statistically significant difference (-value > 0.05). At two spatial points, the differences between direction data were significant, which could be caused by the random errors involved in the validation test. However, the averaged data showed good agreement.
为满足市场对一种价格合理、能测量中大型水体中流速大小和方向范围的仪器的需求，设计并制造了一种流速仪。该流速仪由一个刻度盘和一个摄像头组成，刻度盘中心有一个注射器伸出，摄像头向下悬于刻度盘上方。一旦染料注入流速（DIV）仪置于水流中，染料被注入，摄像头记录染料流体的传输情况。对记录的视频进行分析以确定局部流速和方向。在流动可视化水槽中使用粒子图像测速技术（PIV）对DIV在0.0094米/秒至0.1566米/秒的一系列流速范围内进行了校准。发现该仪器的精度为满量程的+6.3%和-9.8%。校准曲线的决定系数等于98%。校准后，将DIV部署到加拿大卡尔加里的因弗内斯雨水池塘，与声学多普勒流速仪（ADV）进行验证测试。在验证测试期间，在几个空间点测量了流速大小和方向。流速大小结果显示出良好的一致性，曼-惠特尼检验显示无统计学显著差异（p值>0.05）。在两个空间点，方向数据之间的差异显著，这可能是由验证测试中涉及的随机误差引起的。然而，平均数据显示出良好的一致性。
