【作者】 张康乐； 范敏； 刘士和； 罗秋实；

【Author】 ZHANG Kang-le~1,FAN-Min~1,LIU Shi-he~1,LUO Qiu-shi~2 (1.College of Water Resources and Hydroelectric Engineering,Wuhan University,Wuhan 430072 2.Yellow River Engineering Consulting Co.,Ltd.Zhengzhou 450003)

【机构】 武汉大学水利水电学院； 黄河勘测规划设计有限公司；

【摘要】 突跌流动在自然界与工程技术中大量存在,通过实验和数值模拟对突跌流动的自由面变形及相关水力要素变化进行了研究,研究成果表明:(1)在壁面突跌条件下,随着跌坎下游水位的不同,跌坎附近存在缓流衔接、急流衔接与水跃衔接三种衔接形式。(2)跌坎下游存在稳定的回流区,在缓流衔接条件下,回流区纵向长度约为5.5倍的跌坎高度,但在急流衔接与水跃衔接条件下,受自由面变形影响回流区纵向长度有所缩短。(3)在三种衔接形式下,跌坎附近槽底处的时均压强变化以急流衔接形式最为急剧。更多还原

【Abstract】 Flow near the backward facing step occurs in both nature and engineering.In this paper,the deformation of water surface and hydraulic characteristics near the backward facing step have been investigated experimentally and numerically.The results show that:(1)for the backward facing step flow,there are three kinds of flow connection types near the step with different water levels at downstream,that are subcritical flow connection;supercritical flow connection and hydraulic jump connection.(2) there is a steady separation zone just behind the backward facing step, and the length of the separation zone is 5.5 times that of the step height in the condition of subcritical flow connection; however,this length is shorten in the condition of the supercritical flow connection and hydraulic jump connection under the effect of the deformation of water surface.(3) the mean pressure at the channel bottom near backward facing step of supercritical flow connection changes most sharply for all three flow connection types.更多还原