河口时变水流挟沙能力公式  

Formula of time-dependent sediment transport capacity in estuaries

作　　者：孙志林[1] 夏珊珊[1] 朱晓[1] 许丹[1] 倪晓静[1] 黄赛花[1] 

机构地区：[1]浙江大学水利与海洋工程学系,杭州310058

出　　处：《清华大学学报（自然科学版）》2010年第3期383-386,共4页Journal of Tsinghua University(Science and Technology)

基　　金：国家自然科学基金资助项目(40231017;50079025)

摘　　要：为反映河口输沙随潮作非恒定变化的特性,提出了时变挟沙能力的公式。当潮流在加速(减速)过程中由挟沙过剩(不足)的非平衡态向挟沙不足(过剩)的非平衡态转化时存在临界平衡点,此时含沙质量浓度达到极大(小)值。据此机理从若干河口实测非恒定水沙过程提取平衡点数据,结合量纲分析建立河口时变挟沙能力的通用公式。该式与悬移质微分方程的时变体积分数协调一致,避免了半潮平均挟沙能力公式与不平衡输沙之间的矛盾。A time-dependent sediment transport capacity formula was proposed to reflect the unsteady properties of sediment transport in estuaries. The maximum （or minimum） sediment concentration occurs at a critical equilibrium point between two non equilibrium states of sediment carrying excess （shortage） and shortage （excess） during acceleration （deceleration） of the tidal flow. The parameters at the critical equilibrium points are then chosen from the unsteady flow and sediment transport data in several estuaries to develop a general time dependent sediment transport capacity model using dimensional analysis. The formula avoids the contradictions in the semi-tide-averaged concept and non-equilibrium sediment transport with a time dependent sediment concentration in the differential equation for the suspended load. The formula provides a method for numerical simulations of non-equilibrium sediment transport and bed deformation in tidal estuaries.

关 键 词：挟沙能力 时变 平衡机理 河口 

分 类 号：TV143.4[水利工程—水力学及河流动力学]