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本文提出了具大尺度比(长度:深度)区域上流动的二维数值模型,该模型在静压分布假设,鲍辛涅斯克(Boussinesq)假设和刚盖假设基础上求解二维纳维-斯托克斯(Navier-Stokes)方程和能量方程,同时利用可变的涡动系数考虑素流动量及热扩散。流动由表面风剪应力及热输运所引起。文中对矩形域计算了二种情况,计算条件是当表面和底部分别保持为常温时,表面上突然施加一个剪应力,二种计算情况的差别仅仅在于预测涡动粘性和涡动扩散系数时所用的公式不同。文中给出了流速和温度随时间的变化。计算表明,在达到恒定态之前而在一个初始缓慢变化的时期以后,流速和温度均有突然迅速的变化。文中根据对流和扩散的时间尺度的差异及控制方程彼此间的耦合性质解释了这一现象。
In this paper, a two-dimensional numerical model of flow over a large scale (length: depth) region is proposed. This model solves two-dimensional Navier-Stokes equations based on the hypothesis of static pressure distribution, the assumption of Boussinesq and the assumption of rigid- Navier-Stokes equations and energy equations while taking into account the elemental flow and thermal diffusion with variable eddy coefficients. Flow is caused by surface wind shear stress and heat transport. In the paper, two kinds of cases are calculated for the rectangular domain. The calculation condition is that when the surface and the bottom are respectively kept at normal temperature, a sudden shear stress is applied to the surface. The difference between the two kinds of calculation only lies in the prediction of eddy viscosity and eddy diffusion coefficient The formula is different. The paper gives the flow rate and temperature changes with time. Calculations show that there is a sudden and rapid change in flow rate and temperature after an initial slowly changing period before reaching a steady state. This paper explains the phenomenon according to the time scales of convection and diffusion and the coupling properties between control equations.