非漫滩高含沙洪水异常传播机理和临界条件  

Amplification of non-inundating hyper-concentrated flood waves and criterion of its occurrence

作　　者：钟德钰[1] 姚中原[1] 张磊[1] 刘磊[1] 

机构地区：[1]清华大学水利水电工程系水沙科学与水利水电工程国家重点实验室,北京100084

出　　处：《水利学报》2013年第1期50-58,共9页Journal of Hydraulic Engineering

基　　金：国家自然科学基金项目(50979041)国家自然科学基金重点项目(51039004)

摘　　要：黄河下游发生高含沙洪水时常伴随洪峰增值的异常现象,给黄河下游的防洪安全带来了极大的影响。本文基于高含沙水流床面附近存在流凝现象并可能形成具有屈服应力的黏性底层的事实,建立了高含沙洪水分层模型和流动的波系方程,对多沙河流非漫滩洪水洪峰沿程增值现象的机理进行了研究,并给出了发生洪峰增值的临界条件。论文还应用该结果对2004年、2010年发生的黄河下游高含沙洪水增值现象进行了分析。结果表明,当洪水的Froude数大于临界Froude数时,动力波形成的逆扩散导致洪水中的扰动被扩大、集中,从而导致流动失稳,这是这两场洪水洪峰增值的根本原因。Amplifications of flood waves carrying heavy sediment load are often observed in the middle and lower reaches of the Yellow River. The uncertainties of their occurrences and magnitudes have long been threatens to the safety of the residents along the river. In this paper, a two-layer model for the hyper-concentrated flow is developed accounting for the sub-viscous layer with yields stress due to the rheopectic property of hyper-concentrated flows, and a wave hierarchy equation for hyper-concentrated flood is obtained. Two representative flood amplifications occurred in the year of 2004 and 2010, respectively, are examined. Analysis shows that the flood application is closely related to the instabilities of hyper-concentrated flows as a result of the inverse diffusion induced by the dynamic waves, when the Froude number exceeds a certain criterion.

关 键 词：高含沙洪水 洪峰增值 流凝 流动稳定性 

分 类 号：TV143[水利工程—水力学及河流动力学]