弯道水流纵向流速剖面的试验研究

Experimental study on the vertical profiles of longitudinal velocity of flow in a curved conduit

弯道水流特性的研究一直备受重视,而弯道水流纵向流速的分布则是其重要研究课题之一。本文运用弯道概化模型试验,利用ADV采集三维流速数据,对弯道水流纵向流速沿水深的分布进行了系统研究,得到了纵向流速剖面沿程和沿河宽的变化。研究表明,由于弯道水流的复杂性,试图采用单一计算模式来描述弯道纵向流速沿水深的分布是难以实现的。合理的流速剖面公式应当考虑水流参数、弯道尺度和参照部位等的综合影响。研究为进一步深入探讨弯道水流特性奠定了基础。

Study of curved conduit flow and its velocity profiles is an important subject in hydraulics.This paper presents an ADV measurement of 3D velocity data of free-surface water flow in a curved conduit of rectangular cross sections,and makes a systematic analysis on the vertical profile of longitudinal velocity,including its variation along the concave and convex walls and the centerline,and its transverse variation at the inlet,middle section and outlet of the bend.Results show a complexity of the flow and it is difficult or even incorrect to use a single shape to represent the profiles.A rational formula should include factors of flow parameters,bend sizes and position of the reference point,etc.as well as their combination.The present work provides a basis for further study of the bend hydraulics.