论文部分内容阅读
在均匀流条件下对多级复式断面河道中边滩上无植被及有植被情况下的水流特性进行了试验研究.在复式断面渠道的两级阶地上布设钢筋模拟刚性植被,采用三维多普勒超声流速仪(ADV)对三维流场进行了测量,并与无植被条件下的流速场进行了对比试验.根据实测结果,对横断面上的流速等值线图、纵向流速的垂线分布、水深平均纵向流速的横向分布,二次流分布及紊动能分布进行了分析.结果表明:植被的存在,加大了边滩的阻力,促使河道内主流速加速回归河道主槽,二次流主要发生在一级阶地处,最大紊动能亦出现在此处.与无植被多级复式断面比较而言,对数流速定律在二次流及强紊动的影响下,适用范围显著减小.
Under uniform flow conditions, the flow characteristics of vegetation without vegetation and vegetation in multi-level cross-section rivers were studied.Rock simulation rigid vegetation was laid on two terrace of multi-section channels, and three-dimensional Doppler The three-dimensional flow field was measured by ultrasonic flowmeter (ADV), and compared with the flow field under no vegetation condition.According to the measured results, the contour map of velocity, the vertical distribution of vertical flow velocity, The horizontal distribution, secondary flow distribution and turbulent energy distribution of average vertical flow velocity in water depth are analyzed.The results show that the existence of vegetation increases the resistance of side beach, accelerates the main flow velocity in river channel to return to the main channel of river channel, and the secondary flow mainly Occurred at the first terrace, the maximum turbulent energy also appears here.Compared with no vegetation multi-section, the logarithmic velocity law under the influence of the secondary flow and strong turbulence, the scope of application is significantly reduced.