南黄海辐射沙洲西洋水道垂向流速分布计算研究  

Study of vertical velocity distribution calculation of tidal current in Xiyang Channel of radial sandbanks in South Yellow Sea of China

作　　者：肖千璐 李瑞杰[1,2] 

机构地区：[1]河海大学海岸灾害及防护教育部重点实验室,江苏南京210098 [2]河海大学港口海岸与近海工程学院,江苏南京210098

出　　处：《人民长江》2015年第3期9-13,共5页Yangtze River

基　　金：国家自然科学基金项目(41276017);国家海洋局公益项目(201205005-2)

摘　　要：利用传统对数分布描述潮流垂向流速分布时,常与现场实测资料有所偏差。考虑到悬沙垂向分布不均造成的水体分层效应,引入水体分层参数对动量传递系数进行修正,将悬沙垂向指数分布公式应用到流速分布计算中,推导出悬沙梯度引起水体分层效应时的垂向流速分布公式。与南黄海辐射沙洲西洋水道实测流速数据的对比分析表明,该分布与实测数据的相关程度明显高于传统对数分布,垂向流速分布结构更加符合实际情况。由于悬沙在水体底层的减阻作用,得到的摩阻流速小于由对数分布得到的摩阻流速,可以真实反映西洋水道内潮流底部的摩阻特性。The calculated tidal flow velocity profile that is expressed with the usual logarithmic law always departed from the observed data. Stratified flow effect induced by the uneven distribution of suspended sediment is considered and the flux Richardson Number is adopted to modify the coefficient of momentum transfer. The power- type vertical distribution of suspended sediment concentration is applied to the derivation of the vertical distribution,in which,the stratified flow effect induced by the gradient of suspended sediment concentration is taken into account. Through the comparison of the calculated and measured data in Xiyang Channel of radial sandbanks,it is concluded that the new formula of vertical velocity distribution reveals better correlation and consistency with measured data in each layer than the usual logarithmic profile,and conforms more to the actual situation.The vertical density stratification owing to the suspended sediment distribution plays a significant role in the vertical velocity profile. The friction velocity calculated by the formula is smaller than that by the logarithmic profile,because the presented formula considers drag reduction effect of bottom sediment,which reflects the friction characteristic of the bottom in Xiyang Channel.

关 键 词：分层效应 流速垂线分布 摩阻流速 西洋水道 辐射沙洲 

分 类 号：TV14[水利工程—水力学及河流动力学]