北部湾潮汐潮流的数值模拟

Numerical simulation of the tide and tidal current in Beibu Bay

基于正交曲线坐标的ECOMSED三维水动力模式,对北部湾的潮汐潮流进行数值模拟。选用不同的海底摩擦系数、海底粗糙度系数以及水平湍流摩擦系数进行数值试验。试验结果表明,当海底摩擦系数取2×10-3～3×10-3,海底粗糙度系数取1×10-3～2×10-3m,而水平湍流摩擦系数取1×102～5×103m2/s时,模拟所得潮汐、潮流结果与实测数据吻合较好;并由此对北部湾的潮汐、潮流和潮余流等特征进行了分析。还给出了垂直湍流黏滞系数呈抛物型的分布特征。对该海域的水动力状况有了进一步的了解,为该海域的环境保护规划提供了科学依据。

The model ECOMSED with the orthogonal curvilinear grid system is applied to simulating the tide and tidal current in Beibu Bay. We use different coefficients such as bottom friction, bottom roughness and horizontal turbulent friction for the numerical test. The results show that, when coefficient of bottom friction is 0.002 to 0.003, coefficient of bottom roughness is 1×10^-3-2×10^-3m and coefficient of horizontal turbulent friction is 1×10^2-5×10^3m^2/s, the simulations of the tide and tidal currents agree generally with the observation. The characteristics of the tide, tidal current, and residual current in Beibu Bay are investigated based on the simulation. The vertical turbulent coefficients were found to display a parabolic structure. This study offers more understanding about the hydrodynamic condition in Beibu Bay and provides a scientific basis for the program of environmental protection.