1. China Jiliang University, Hangzhou, Zhejiang 310018, China;
2. Hangzhou Institute of Calibration and Testing for Quality and Technical Supervision, Hangzhou, Zhejiang 310019, China
Abstract：According to the ISO 748, when the uncertainty of open channel discharge measurement was evaluated, the sufficient measurements and verticals need be set in the crosssection, but velocity interpolation to the edge and in the top/bottom layers are not taken into account. In order to solve the problems, a new approach is introduced for evaluating the uncertainty. The vertical velocity and transversal mean velocity distribution model of crosssection were achieved with FLUENT. In the experiment, the uncertainty caused by limited number of velocity measurements points and measurement verticals were computed with the velocity distribution models respectively. The uncertainty components are analyzed to calculate the uncertainty of discharge measurements. The experiment results showed that the method improves the accuracy of the measurement uncertainty.
［1］Pelletier P M. Uncertainties in the single determination of river discharge: a literature review ［J］. Canadian Journal of Civil Engineering, 1988, 15: 834-50.
［2］Simpson M R. Discharge measurement using a broad band acoustic Doppler current profiler［R］.United States Geological Survey, Open File Report, 2001, 50-53.
［3］Le Coz J, Camenen B,Peyrard X. Uncertainty in openchannel discharges measured with the velocityarea method［J］. Flow Measurement and Instrumentation, 2006, 26: 18-29.
［4］Nezu I, Nakagawa H.Turbulence in Open Channel Flows［J］. Journal of Hydraulic Engineering ,1993, 120(10): 1234-1237.
［5］ISO 748—2007. Hydrometry measurement of liquid flow in open channels using currentmeters or floats［S］. 2007.
［6］孙东坡, 王二平, 董志慧,等.矩形断面流速分布的研究及应用［J］.水动力学研究与进展, 2004, 19(2): 144-152.
［7］胡云进, 万五一, 蔡甫款,等.窄深矩形断面明渠流速分布的研究［J］.浙江大学学报(工学版), 2008, 42(1): 83-88.
［8］张海滨, 王中宇, 刘智敏.测量不确定度评定的验证研究［J］.计量学报, 2007, 28(3): 193-197.
［9］谢少锋, 陈晓怀, 张勇斌.测量系统不确定度分析及其动态性研究［J］.计量学报, 2002, 23(3): 237-240.
［10］崔孝海, 区璐. 蒙特卡罗方法在微波功率测量不确定度分析中的应用［J］.计量学报, 2008, 29(1): 77-79.
2015, Vol. 36 
