河流水面成像测速研究进展

Research progress on river surface imaging velocimetry

大尺度粒子图像测速(LSPIV)是一种用于测量大面积(数百平方米)水体表面流速的非接触式全场流速测量技术。不仅可用于常规条件下明渠紊动特性和时均特性的研究,更具有极端条件下河道水流监测的应用潜力。然而受复杂现场环境的影响,该技术在天然河流的应用中面临着诸多挑战。从水流示踪方式、流场图像采集、水面目标增强、运动矢量估计、时均流场重建、水面流场定标及不确定度评估七个方面综述了国内外对河流水面成像测速(RSIV)方法的研究进展。通过对现有方法的总结和讨论,提出改进技术方法的研究需求,以使其成为水动力学和水文学中有力的测量工具。

Large-scale image velocimetry （LSPIV） is a non-intrusive technique to measure whole-field velocities at the free-surface of a water body spanning large flow area （ up to hundreds of square meters）. It not only can be used to study the turbulence and time-aver- aged characteristics of open-channel flows under normal conditions, but also the great potential is exhibited for river flow monitoring un- der extreme conditions. However, due to the complex field conditions, it is faced with quite a number of challenges in the application of natural rivers. The research progress on river surface imaging velocimetry （RSIV） is reviewed from the seven respects, including： flow tracing, image capturing, target enhancement, motion vector estimation, time-average flow field reconstruction, flow field calibration and uncertainty evaluation. Results and a critique of existing methods are discussed to propose research requirements and to improve its capabilities to be a promising measurement tool for hydraulics and hydrology.