明渠近壁区水流的紊动特性分析  

Analysis of Dynamical Characteristics of Turbulence in Near Bed Regions of Open Channel

作　　者：楚万强[1,2] 曹明伟 

机构地区：[1]小流域水利河南省高校工程技术研究中心,河南开封475003 [2]黄河水利职业技术学院,河南开封475003

出　　处：《水力发电》2014年第3期75-78,共4页Water Power

摘　　要：根据ADV采集的试验水槽中的三维流速,运用紊流统计理论,从流速概率分布、紊动强度、雷诺应力和紊动动能概率分布方面,对明渠近壁区水流的紊动特性进行了分析。可得:在近壁区,横向、纵向分流速及合成瞬时流速的概率分布与正态分布相似,而垂向上则偏差较大;横向的紊动强度和雷诺应力的分布形式与纵向相似,值略小,垂向趋于一个常数;利用试验数据统计得到的紊动动能概率分布与同性均匀湍流条件下理论推导的概率分布进行了对比,说明三维流场结构下,紊动动能的概率分布更符合卡方分布。进一步根据紊流的三维紊动特性,指出应该根据水流涡团运动在方向和大小上的瞬变性,从三维方向上考虑泥沙起动时的受力。According to three-dimensional velocity data collected by ADV, the turbulence statistical theory has been used to analyze the dynamical characteristics of turbulence in the near bed regions from the probability distributing functions of velocity, fluctuating intensity, Reynolds stress and turbulent kinetic energy. The results show that： （a） in the near bed regions, the velocity probability distribution functions in X-direction and Y-direction are similar to corresponding normal distributions, but the Z- direction velocity is different; （b） the distribution forms of fluctuating intensity and Reynolds stress in X-direction are similar to Y-direction, but the value is less, and the value in Z-direction tends to a constant; and （c） the probability of turbulent kinetic energy calculated from measured data is compared with the theoretical result under homosexual uniform turbulent condition, and the shape is similar to Chi-square distribution. Furthermore, by considering the transient of the direction and size of the flow vortex motion, the sediment stress should be calculated from three-dimensional direction.

关 键 词：紊动水流 紊动特性 ADV 统计分析 明渠近壁区 

分 类 号：TV133[水利工程—水力学及河流动力学]