Analysis on Mechanism of Mixing and Turbulent Diffusion in Tidal River Estuary

本课题的研究成果由Hiji潮河的现场实测、三层流态的实际验证和潮密度流的数值模拟组成。野外观测;利用双元电磁传感器系统对海鸡河口进行了潮汐口观测。另一套测量系统（螺旋桨仪、电导率和水温）同时搜索盐斜周围的测量范围。由A/ d转换器和可选放大器支持的16<beta>-个人计算机系统进行从模拟量到离散量的排列。实际的验证;首先，从平均值测量中获得时间平均速度和盐度。与这些结果相对应，对u‘u’、w‘w’、u‘w’、混合长度和涡流粘度进行了详细的分析。然后利用这些物理量成功地验证了三层流模型。其次，用Iwasaki数或Richardson数的幂函数分别表示界面上相互夹带的数值评价。数值模拟;用fdm模拟了垂直平面上的二维密度流

The results of this project are composed of field measurements in Hiji Tidal river, practical verification for Three-layered Flow Modal and Numerical simulation of tidal density flow.1. Field Observation; Tidal estuary observations were carried out by the electromagnetic sensor system with two-elements in Hiji river estuary. The range of measurement arround halocline were searched by the other system(propeller meter, electric conductivity and water temterature) simultaneausly. The arrangement from analogous to discrete quantity were coducted by 16<beta>-personal computer system supported by A/D-converter and optional amplifier.2. Practical Verification; First, time-averaged velocity and salinity were obsatined from the mean values measurements. Corresponding these results, the detailed analysis of turbulent fluctuations which were u'u', w'w', u'w',mixing length and eddy viscosity were fulfilled. And then, Three-layered flow model were verified with these physical quantities successfully. Second, numerical evaluation of mutual entrainments across the interfaces were represented by a power function with respect to Iwasaki number or Richardson number respectively.3. Numerical Simulation; Two-dimensional density flow in vertical plane were simulated by F.D.M.