Abstract
When using point measurement for environmental or sediment laden flows, there is well-recognised risk for not having aligned measurements that causes misinterpretation of the measured velocity data. In reality, these kinds of mismeasurement mainly happen due to the misinterpretation of bed orientation caused by the complexity of its determination in natural flows, especially in bedload laden or rough bed flows. This study proposes a novel bed realignment method to improve the measured data benchmarking by three-dimensional (3D) bed profile orientation and implemented it into different sets of experimental data. More specifically, the effects of realignment on velocity profile and streamwise turbulence structure measurements were investigated. The proposed technique was tested against experimental data collected over a water-worked and an experimentally arranged well-packed beds. Different from the well-packed rough bed, the water-worked bed has been generated after long sediment transport and settling and hence can be used to verify the proposed bed-alignment technique thoroughly. During the flow analysis, the corrected velocity, turbulence intensity and Reynolds stress profiles were compared to the theoretical logarithmic law, exponential law and linear gravity (universal Reynolds stress distribution) profiles, respectively. It has been observed that the proposed method has improved the agreement of the measured velocity and turbulence structure data with their actual theoretical profiles, particularly in the near-bed region (where the ratio of the flow measurement vertical distance to the total water depth, z/h, is limited to ≤0.4).
Highlights
There is a well-known fact that a lot of observed data cannot achieve good accuracy in natural and real-world flow conditions
The flow velocity distributions within different well-packed rough bed and sediment transport-induced water-worked bed experiments were analysed, where the studied flow region was focused on z/h ratios of
For the rough bed flow, κ = 0.44, Br = 7.4 and Π = 0.0792 were used, while κ = 0.44, Br = 6.3 and Π = 0.0767 pwere set for the water-worked bed flow [18]
Summary
There is a well-known fact that a lot of observed data cannot achieve good accuracy in natural and real-world flow conditions. This is typically difficult to monitor in the natural flow streams where the local bed profile orientation cannot be clearly observed. Can result from the bed orientation that displaces the actual measured line from the expected measured line The water-worked rough bed is achieved by long sediment transport and settling processes, where it was introduced by Cooper and Tait [14] With these tests, this study can fully validate and identify the performance of the proposed bed realignment approach in correcting streamwise velocity and turbulence structure profiles. The investigation of this study will be concentrated at the near-bed flow region (z/h ratio of
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
