钱塘江河口弯道潮流场的数值模拟

Numerical simulation of tidal flow field in the Qiantang Estuary bends

钱塘江河口潮流错综复杂,依靠零星的实测潮流资料无法全面描述其流场特征.本文采用Deldt3D模型对钱塘江河口闻家堰至仓前河段的潮流场进行二维数值模拟,着重研究了河口弯道的流场特性.结果表明,河口弯道流场具有跟无潮河流弯道显著不同的特性,如弯道流速向下游递增;涨、落急主流线分歧;涨、落潮流对丁坝工程的响应不同,以及下游弯道水面横比降大于上游弯道.

Tidal flow in the Qiantang River estuary is very complex and cannot he fully described hythe measured da ta on water level and velocity of a few points. Delft3D Model is used to numerically simulate flow field ira the reach from Wenjiayan to Cangqian, especially in several bends of this estuary. The results indicate that flow field in the bends of tidal estuary differs obviously from that in the bends of non-tide river, including the downstream increase of velocities in the estuarine bends, the bifurcation of main streamlines and different response of tidal flow to groync in the ebb period and flood period, as well as larger transversal slope of water surface in the lower bend than in the up per bend.