【作者】 梁书秀； 张怡辉； 孙昭晨；

【Author】 Liang Shu-xiu;Zhang Yi-hui;Sun Zhao-chen;State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology;

【机构】 大连理工大学海岸和近海工程国家重点实验室；

【摘要】 首先利用TurboMAP-9对渤海海峡北部进行了观测,给出了夏季该海域的温跃特征。基于实测的温度数据,采用三维水动力模型-FVCOM,对该海域进行了三维数值模拟,通过与实测混合系数的对比,初步分析了MY-2.5紊流封闭模式对该海域垂向混合特征的模拟能力。首先给出了垂向平均混合系数与流速的变化关系,可以发现模拟的Km、Kh呈现出显著的随流变化特征,且在时间上呈现出变化的滞后性。速度变化对混合系数垂向平均量级变化的贡献在等温场和温度分层下分别可达到1个和2个量级。在不考虑风的影响下,模拟的Km、Kh等温场下呈现表、底层略小,中间大的垂向分布特征;温度分层时,呈现上部量值很小,底部量值较大的垂向分布特征。不同温度条件和不同水深处均与实测的分布形态不同。量级上,模拟的Km、Kh的值,深水区与实测值差异较大。更多还原

【Abstract】 According to the field observation made use of the Turbulence Ocean Microstructure Acquisition Profiler(TurboMAP) in the Bohai Strait, the distribution of thermocline is analysed firstly in summer in this paper. Based on the measured temperature, the three dimensional numerical model based on the hydrodynamic module of FVCOM was established for the Bohai Strait and a preliminary analysis of simulation capabilities of vertical mixing characteristics using the MY-2.5 turbulence closure model has been made by comparing with the measured mixing coefficient. Firstly, the relationship between the simulative average mixing coefficient and the simulative velocity was analysed and the conclusion that the simulative vertical average mixing coefficient of Km and Kh showing a significant change with the flow velocity and having a time delay compared to the change of flow velocity could be found. Under the influence of the flow velocity changing, the changing magnitude of vertical average mixing coefficient was one order of magnitude in isothermality and two orders of magnitude in temperature stratification respectively. Without considering the effect of the wind, the magnitude of simulative vertical mixing coefficient is slightly larger in the middle under constant temperature; However, The magnitude of vertical mixing coefficient is small on the upper part and large at the bottom side in temperature stratification. The distribution shape of simulative mixing coefficient is distinguishing from that of measurement mixing coefficient under different temperature condition and depth of water. There is an obvious difference on magnitude between simulative mixing coefficient and measurement mixing coefficient in deep water.更多还原