Estimation of Critical Uncertainty Sources in Discharge Measurements using Controlled Experimental Conditions

Abstract

Providing experimental results along with associated uncertainties is essential not only for ensuring confidence in the quality of the final results but also for guiding improved instrument design and the protocols for measurement acquisition. Moreover, if the uncertainty analysis is conducted in a controlled manner and over a wide range for the measured variables its results can serve as a decision-making aid in conducting new experiments. This paper provides three examples of end-to-end assessments of the impact of uncertainty sources involved in the discharge estimation in open channels using point velocities measured with Acoustic Doppler Velocimeter. The analyzed uncertainty sources are: a) the sampling duration for velocity measurement, b) the number of points in the verticals, and, c) the number of verticals across the measurement cross-section. The raw data for the uncertainty estimations were acquired at the KICT River Experiment Center (South Korea), an experimental facility designed for facilitiating quasi natural-scale experiments. The three sources of uncertainties are assembled in practical visualization means that can be used for planning the acquisition of new experiments with similar instruments.