黄河水流阻力及河床比降计算方法研究OA北大核心CSTPCD
Study on calculation of flow resistance and riverbed slope of the Yellow River
冲积河流动床阻力对洪水演进、河床冲淤变形分析有重要影响.本文首先利用黄河下游现场测验资料,分析了多个单水力因子及无量纲水力参数与糙率系数的相关关系,认为影响糙率的主要水力因素是水深、比降、含沙量及河道纵向稳定系数.之后,以张罗号流速一般表达式为基础,借助河流过程原理,确定了水深指数与比降指数,以反映流速梯度、河床稳定性及输沙强度等物理特性对水流阻力的影响;同时提出河床比降与能坡计算式,该公式不再采用观测误差较大的水面比降值直接替代水力坡度,从而提高了糙率计算精度.最后建立出适用于黄河,仅需较少实测参数即可推求水流阻力的计算式.经黄河干支流3188组实测资料验证表明:本文计算方法得到的糙率与实测值更为相近,相关系数0.894,相对误差16.5%.本文方法可为黄河水流阻力计算提供理论支持.
The study of flow bed resistance in alluvial river has a significant impact on flood evolution and riverbed deformation.Therefore,this article first analyzes the correlation between multiple single hydraulic factors,dimen-sionless hydraulic parameters and roughness coefficients using the field test data from the lower reaches of the Yellow River.It concludes that the primary hydraulic factors influencing roughness are water depth,slope,sedi-ment concentration,and longitudinal stability coefficient of the river channel.Subsequently,based on the general expression of Zhang's flow velocity and principles of river dynamics,the study determines indices for water depth and slope,which reflect the effects of physical characteristics such as velocity gradients,riverbed stability,and sediment transport intensity on hydraulic resistance.Then,a formula for calculating riverbed slope and hydraulic energy slope is proposed,which avoids using surface slope values with significant observation errors to directly sub-stitute the hydraulic gradient,thereby enhancing the accuracy of roughness calculations.Finally,a formula suitable for the Yellow River was established,which can be used to calculate the flow resistance with only a few measured parameters.Verified by 3188 sets of measured data from the main and tributaries of the Yellow River,the roughness calculated using this method is quite similar to the measured values,with a correlation coefficient of 0.894 and a relative error of only 16.5%.The method in this paper can provide theoretical support for the calcula-tion of water flow resistance in the Yellow River.
侯琳;张红武;李琳琪;李希稷
清华大学水沙科学与水利水电工程国家重点实验室,北京 100084山东潍坊抽水蓄能有限公司,山东潍坊 262600
水利科学
水流阻力河床比降黄河糙率河床纵向稳定系数
flow resistanceriverbed slopethe Yellow Riverroughnesslongitudinal stability coefficient of river-bed
《水利学报》 2024 (009)
1020-1032 / 13
国家重点研发计划项目(2016YFC0402500);国家自然科学基金青年科学基金项目(52009145);鄂尔多斯水利科技重点项目(20232000090)
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