柔性植物阻流特性研究

河流中的植物不仅影响河流的泄洪能力而且在生态的修复中起重要作用,因此对含植物明渠水流的阻力特性及紊流特性的研究显得非常重要。将河道中含柔性植物的水流视为充分发展了的紊流,在实验室中用特定材料模拟柔性植物,通过水槽试验用三维ADV对淹没柔性植物段紊流特性进行了测量研究,分析了含淹没柔性植物明渠水流的水力学特性及阻力特性并得出其曼宁糙率n的变化规律。对试验结果分析表明,含淹没柔性植物的垂向流速分布不再符合指数分布;其紊流具有明显的各向异性特性;植物冠层交界处,水流紊动交换强烈,该处紊流强度及雷诺应力出现最大值。

Flow resistance of flexible vegetation in open channel

Vegetations apply great effect not only on flood discharge but also on river restoration.It is important in studying the characteristics of flow resistance and turbulence reduced by vegetated flow.Vegetated open channel flow is considered as well developed turbulence.Flexible vegetation is modulated by a special material in laboratory.Flume experiments were taken on studying the vegetated turbulence by means of ADV.The results of hydraulics and resistance of vegetated flow are analyzed.And the Manny's n was acquired.The results show that the velocity profile is not accord with the exponential rule,the anisotropy is obvious.The flow exchange violently on the top of the vegetation.The turbulence intensity and the Renault stresses were achieved the maximum value.