Large eddy simulation of turbulent statistical and transport properties in stably stratified flows
Large eddy simulation of turbulent statistical and transport properties in stably stratified flows
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稳定分层流中湍流统计和输运特性的大涡模拟
DOI：
10.1007/s10483-009-0203-x
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发表时间：
2009
期刊：
影响因子：
--
通讯作者：
卢志明
中科院分区：
文献类型：
--
作者：
卢志明
采用三维大涡模拟（LES）研究了具有尖锐热界面的稳定分层湍流。主要结果集中在湍流的特征尺度，统计性质，输运性质，时间和空间演化的标量场。结果表明，浮力尺度先增大，然后趋于某一定值。平均切变越强，浮力尺度越大。倾覆尺度随流量的增大而增大，平均切变使倾覆尺度增大。温度的平坦因子在相当大的区域内偏离高斯分布，其统计性质明显不同于强分层情况下的速度涨落。湍流混合从小尺度运动开始，然后扩展到大尺度运动。
Three dimensional large eddy simulation (LES) is performed in the investigation of stably stratified turbulence with a sharp thermal interface. Main results are focused on the turbulent characteristic scale, statistical properties, transport properties, and temporal and spatial evolution of the scalar field. Results show that the buoyancy scale increases first, and then goes to a certain constant value. The stronger the mean shear, the larger the buoyancy scale. The overturning scale increases with the flow, and the mean shear improves the overturning scale. The flatness factor of temperature departs from the Gaussian distribution in a fairly large region, and its statistical properties are clearly different from those of the velocity fluctuations in strong stratified cases. Turbulent mixing starts from small scale motions, and then extends to large scale motions.