Author(s): Ying-Sung Hsu; Yu-Ting Lee; Sheng-Yo Lin; Yung-Ping Huang; Yong-Huang Wu
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Keywords: Resonance frequency; Bed-load transport; Vibration tube
Abstract: Hydrological and sediment monitoring is important for river management. Accurate monitoring of suspended load and bed-load transport facilitatesan understanding of river bed changes for flood and disaster prevention control. Numerous techniques can be employed to measure suspended load, whereas few strategies exist for monitoring and measuringbed-load transport. Measurement limitations necessitate using a certain proportion of suspended load to estimatethe bed-load transport. The principles of an acoustic vibration tube were adopted in this study, and energy changeswere employed to estimatethe bed-load transport for further discussions. Under an identical impact environment, the resonance frequency of the vibration tube does not change with various impact objects. However, differences exist in the intensity of the fixed resonance frequency. Therefore, glass and steel beads with differing particle diameters were used to conduct impact tests in a laboratory channel. The experiment control criteria included placing a vibrationtubein air or flowing water, varying the particle diameter and number, and adjusting the channel slope. The resonance frequency of the vibrationtube upon impact was recorded using a high frequency strain gauge, and the energy spectrum was used to conduct a fast Fourier transform analysis. The results indicate that the size of the impact particles have a more significant influence on energy than the other parameters. The energy produced by particle impact significantly increased with the channel slope and flow velocity. The results of this study were used to establish a relationship trend for sediment discharge and vibration tube energy to serve as a reference for future studies.
Year: 2013