【作者】 邱翔； 张道祥； 卢志明； 刘宇陆；

【Author】 QIU Xiang ZHANG Dao-xiang LU Zhi-ming LIU Yu-lu Shanghai University,Shanghai Institute of Applied Mathematics and Mechanics,Shanghai 200072

【机构】 上海大学上海市应用数学和力学研究所；

【摘要】 本文采用大涡模拟方法研究了上下两层温度不同的稳定分层湍流,主要对其中的湍流混合层的演化进行了分析研究．结果表明在相同的剪切条件下,稳定分层对湍流脉动的产生起到了抑制作用,并加快了湍流脉动的衰减；在相同的分层条件下,剪切效应的促进了湍流脉动的产生,使得湍流度增大．同时还发现,由于剪切的存在,混合层呈现不对称性而向速度较小一侧偏移；稳定分层则抑制了混合层的发展,使得混合层变薄,说明分层抑制了垂向的温度扩散。更多还原

【Abstract】 In this paper,LES of the stably stratified turbulence,which has two different temperatures in up and down layers,was performed.Then evolution of turbulent mixing layer was analyzed in details.When the stratification intensity is fixed,the stable stratification suppresses the generating of turbulence,and accelerates the decaying of turbulent fluctuations.And under the same stratification, the shear strengthens the generating of turbulent kinetic,which means higher turbulent intensity.Due to the effect of shear,the mixing layer is deviated to the side with small inlet velocity and makes the mixing layer asymmetry.However,the stable stratification restrains the developing of the turbulent mixing layer,which means that the stratification suppresses the dispersion of temperature.更多还原