复式河槽综合糙率计算方法比较与分析  

Analysis on methods for predicting composite roughness of river channel with compound cross section

作　　者：杨克君[1] 曹叔尤[1] 刘兴年[1] 

机构地区：[1]四川大学水力学与山区河流开发保护国家重点实验室,四川成都610065

出　　处：《水利学报》2005年第7期780-786,共7页Journal of Hydraulic Engineering

基　　金：国家自然科学基金资助项目(50279024);高等学校博士学科点专项科研基金资助课题(20030610039)

摘　　要：综合糙率是复式河槽水力计算的一个重要参数。本文系统地总结了推求综合糙率的各种典型方法,包括Pavlovskij方法,EinsteinBanks方法,Lotter方法,KrishnamurthyChristensen方法以及DracosHardegger方法。运用277组复式河槽水槽实验资料和野外实测资料,验证了上述各种方法的有效性。通过比较和分析,发现这些方法都不适用于估算复式河槽综合糙率。本文对这些方法产生误差的原因进行了分析,并指出产生误差的原因在于前四种方法忽略了滩槽动量交换;后一种方法虽然考虑了动量交换,但该方法并不普遍适用。本文对现有资料的分析,提出了一个滩槽糙率相同情况下的复式河槽综合糙率关系式。Experimental result and field observation data are used to check the validity of the currently used methods for predicting composite roughness of river channel including the Pavlovskij Method,Einstein-Bank Method, Lotter Method, Krishnamurthy-Christensen Method and Drasco-Hardegger Method.The comparison shows that the accuracies of the first four methods are poor and they are not suitable for predicting the roughness of river channel with compound cross section due to neglecting the momentum transformation. The last method cannot be used popularly since it is an empirical formula, in spite of the transfer of momentum is considered. Based on the data obtained an improved method for calculating the roughness of river having the same roughness in main channel and floodplain is proposed.

关 键 词：复式河槽 综合糙率计算方法 比较与分析 相对误差 方法改进 

分 类 号：TV133[水利工程—水力学及河流动力学]