窄深式矩形明渠紊流流速分布规律研究

针对目前明渠流速分布计算中所存在的问题，考虑窄深式矩形渠道流速分布受侧壁影响大，选取能反映侧壁处竖向流速分布规律的抛物线形式，根据三维雷诺方程，建立了矩形渠道的紊流数学物理模型，推导出了水流受侧壁影响下的全断面流速分布公式和平均流速横向分布公式。通过矩形水槽实验，验证表明，在y/h>0.2时，侧壁处的测点误差都在5%左右，渠道中心区域误差在3%以内；但在y/h<0.2误差比较大，最大误差达10%。与以往紊流公式相比，精度更高，物理意义更加明确，表明本文公式能较好地反映紊流流速分布特性，具有较高的理论意义和实用价值。

Study on Velocity Profile of Turbulent Fluid in Narrow Deep Type Rectangular Channel

To explore velocity distribution of turbulent flow in rectangular channel under the influence of sidewall, comparison and analysis of the main formula of velocity distribution which are applicable to rectangular channel in current were presented and the advantages and disadvantages were listed. Selecting the parabolic distribution form which reflects vertical velocity distribution near sidewall well. According to the three-dimensional Reynolds equation, a model of mathematical physics on turbulence was created. Cross-sectional velocity distribution formula and average velocity transverse distribution formula under the influence of side-wall were deduced. Calculation results by formula and measured velocity data in rectangular channel were compared. if y/h>0.2, The relative error between measured value and calculated value is less than or equal to 3% in channel central region, and the relative error is at about 5% in side-wall region; if y/h<0.2 , the maximal error is about 10%.The formula can reflect velocity distribution along the vertical and horizontal well, which has important theoretical significance and practical value.