Practical techniques for measurement and analysis of fluctuating components in large scale hydraulic model test in open air --- A case study of cut-off channel flow---

Abstract

This paper discusses practical techniques to measure fluctuation of velocity as well as of water surface level in a large scale hydraulic model test which is often carried out in open air. 1/70 scale model of a cut-off channel of actual river was used for the purpose. PIV measurement by using a fine resolution digital camera with short interval shooting was adopted for continuous velocity measurement in a wide area. A set of six servo level gauges was used for time series measurement of water level on each transect line. The data sets obtained separately by the methods mentioned above were synchronized by referring to a time series of water level measured at a fixed station. Correlation analysis of the synchronized data clarified the coherency of periodic fluctuation in time and space, and practical efficiency of the method was verified.