文献类型：期刊文献

中文题名：湍流热对流大尺度环流反转时的角涡特性

英文题名：Corner vortex characteristics at the reversal of large scale circulation in turbulent Rayleigh-Bénard convection

作者：包芸[1];宁浩[2];徐炜[1]

机构：[1]中山大学力学系;[2]广东海洋大学海洋与气象学院

年份：2014

期号：15

起止页码：287

中文期刊名：物理学报

外文期刊名：Acta Physica Sinica

收录：CSTPCD、、北大核心2011、EI(收录号：20143218042751)、Scopus(收录号：2-s2.0-84905252619)、北大核心、CSCD、CSCD2013_2014

基金：国家自然科学基金(批准号:11372362)资助的课题~~

语种：中文

中文关键词：热对流;大尺度环流;反转现象;角涡特性

外文关键词：Rayleigh-Benard convection； large scale circulation； reversal； corner vortex

中文摘要：本文采用DNS方法计算二维方腔Rayleigh–Bénard热对流.在软湍流区热对流场呈现大尺度环流和两个反向转动的角涡,并出现了大尺度环流的反转现象.连续的温度等值线和流线图清晰地描述了反转现象的全过程.在反转过程中,角涡的大小尺度变化起到重要的作用.对角涡大小尺度变化的分析发现,在反转现象中其角涡尺度随时间的变化出现剧烈的振荡,而没有反转现象的热对流场中角涡尺度变化只有小幅的脉动.对反转过程前后的角涡大小尺度、典型位置速度及角点附近温度等流动特性进行了探讨和分析,发现反转是在瞬间完成的,角涡内速度脉动较小、温度较高,反转前角涡尺度与角涡侧壁垂向速度变化具有同步性.

外文摘要：The two-dimensional Rayleigh-Benard convection is calculated by DNS method. A large scale circulation and two corner vortices with reverse rotation are presented in soft turbulent convection, and the reversal phenomenon of the large scale circulation appears. Continuous temperature contour and the streamline chart describe the whole process of the reversal clearly. In the process of the reversal, the changes of the corner vortex size play an important role. Analysis of the corner vortex size change shows that the changes appear violent oscillation in the thermal flow field with the reversal, but only slight pulsation is found without the reversal. Corner vortex size, velocity at the typical position, and the temperature near the angle location in the process of reversal are discussed. The reversal is found to be done in an instant, and the velocity pulse is smaller and the temperature is higher in the corner vortex. The corner vortex size and the vertical velocity on the side wall vary synchronistically before the reversal.