The main reason of the stepped spillway having greater energy dissipation is tha there is big horizontal vortex in the inner angel of the steps and it makes momenbo exchange with outer mainstream then accelerates the theulence in the water 由于阶梯的存在，使得水流在阶梯凹角内产生强烈的水平横轴旋涡，旋滚水流与外部主流之间不断进行的动量交换加剧了水流内部的紊动，从而使阶梯溢流坝有较高的消能率。
On every step , the maximum of the turbulence dissipation rate is at the step tip . because the interaction between the skimming flow and the step tips causes the energy to dissipate continuously , so that the step can have better energy dissipation results 在每个阶梯上，紊动耗散率的最大值出现在阶梯的突角处，正是由于滑移主流与阶梯突角之间的相互作用使能量不断耗散，从而使阶梯具有良好的消能效果。
The potential problems related to the applications of k - model under the new coordinates are analyzed and the distribution formula of vertical turbulence viscidity coefficients is deduced on the base of logarithmic velocity of flow according to the characteristics of the model 分析了在新坐标系下应用k -模型可能存在的问题，并从模型的特点出发，以对数流速分布为基础，导出了垂向紊动粘性系数的分布公式。
2 , application of the modified k - e model by munk - anderson equation to gravity flow in reservoir shows that the modified model overestimates the turbulent intensity in reservoir . it results enhance of momentum exchange in vertical direction and large error in velocity 采用munk - anderson修正的-模型模拟水库重力下潜流，发现该修正模型过高地估计了水库的紊动强度，使垂向动量传递加大，流速误差明显增加。
By using the three - dimension acoustic doppler velocimeter to measure velocities of flow in an ecological river before and after arrangement of cropping loops , the velocity distribution , turbulence intensity and reynolds stress before and after arrangement of cropping loops are compared 摘要采用三维超声波多普勒测速仪对河道生态修复中种植圈布设前后的工况量测，比较了布设种植圈前后的流速分布、紊动强度和雷诺应力的变化。
The effect of groyne length and layout on water surface is analyzed in the paper . based on the results of simulation and experiment , the local energy loss of the flow due to the groyne is studied . consequently the surface variation and height of damming are also analyzed 论文分析了丁坝长度与布置对水面线的影响，根据流场、紊动场模拟结果和实验结果研abstract究丁坝造成的水流局部能量损失，并对水面变化和丁坝奎水高度进行了分析。
On the base of summarizing the results , the law of vertical turbulent mixing and transportation in the natural river is researched and applied in numerical model through the theoretical derivation combined with analysis of the data of measurement in this dissertation 本文在总结分析前人研究成果的基础上，通过理论推导、现场资料分析和数值模拟相结合的方法，着重研究天然河流中物质的垂向紊动混合、输移的基本规律，并将这些规律运用于数学模型的数值计算中。
Based on previous study of pollutant dispersion in vertical direction , an empirical formula for determining the mean value of turbulence viscosity coefficient in numerical simulation of tides in vertical direction was worked out and applied to 3 - d numerical simulation of tides for changxing island reach in yangtze river estuary 摘要在已有污染物垂向扩散过程研究的基础上，提出了确定潮流数值模拟中垂向紊动黏性系数的垂线平均值的经验方法，并将此方法应用到长江口长兴岛段的潮流三维数值模拟中。
P . r . c abstract the study of the turbulent mixing and transportation in the natural river is of theoretical and practical importance . plenty of indoor and outdoor experiments , theoretical analysis and application research on this object have been performed , and have bought about a lot of results by many investigators 天然河流中的紊动混合及输移规律，是一个在学术上及应用上都具有重要意义的研究课题，国内外学者曾进行大量的室内外的实验、理论分析和应用研究，取得许多研究成果。
A three - dimensional - acoustic doppler velocimeter is used to measure the velocity components of the flow field in all three coordinate directions for different discharge and measurement site . the influence of measurement site and the depth / vegetation height ratio on the measured velocity profile and turbulence intensity and the renolds stress is analyzed . the characteristics of the measured velocity distributions and the results of the previous investigators are used to select an analytical expression for the shape of the velocity profile 利用三维超声波多普勒流速仪( adv )量测不同位置、不同流量下的瞬时流场。分析了测点位置和水深与植被高度比对时均流速分布的影响。本文还给出了种树段紊动强度及雷诺应力的垂线分布。
