建闸河口闸下潮波变形数值模拟研究

Numerical simulation of tidal wave deformation downstream sluice in estuary

我国河口建闸之多,闸下河道淤积之严重,世界罕见。众多学者对建闸河口闸下淤积的机理进行了系统的分析和研究,认为潮波变形是造成闸下河道淤积的动力因素,闸下引河长度(河口到闸的距离)不同,潮波变形的特征也有所不同,淤积形态和特征也不相同。在潮波变形概化物理模型试验的基础上,建立了二维潮流数学模型,通过数值模拟计算,得出了不同引河长度时的潮波变形特征,为预测和分析不同闸址建闸所引起的淤积特性分析提供研究依据。

Siltation in the rivers downstream of floodgates is serious in China, making the discharge capacity of rivers decrease obviously and threatening the flood control in upper rivers. Tidal wave deformation is one conclusive dynamic factor leading to siltation downstream floodgates in estuaries. The hydrodynamic characteristics of tidal wave deformation are different with different river lengths downstream floodgates, so the fluvial processes and morphology characteristics are also different. A 2D numerical model is established to simulate the tidal wave deformation with different-length river downstream the floodgate. The changes of tidal level, flow velocity and phase difference are simulated before and after the construction of floodgate. The length of river downstream floodgates influences tidal wave deformation obviously, and several conclusions are obtained to provide a theoretical basis for the prediction and analysis of the siltation characteristics in the lower reach caused by floodgates with different lengths in estuaries.