On the scalar turbulent/turbulent interface of axisymmetric jets
On the scalar turbulent/turbulent interface of axisymmetric jets
复制标题
轴对称射流的标量湍流/湍流界面
DOI：
10.1017/jfm.2022.825
复制
发表时间：
2022
影响因子：
3.7
通讯作者：
S. Gaskin
中科院分区：
文献类型：
--
作者：
Khashayar F. Kohan;S. Gaskin
研究了零平均流湍流环境对轴对称射流湍流/湍流界面（TTI）几何形状的影响，并与传统的湍流/非湍流界面（TNTI）进行比较。环境湍流是使用随机射流阵列产生的。利用平面激光诱导荧光捕获了受不同环境湍流强度和长度尺度影响的射流的正交截面。浓度从射流核心向界面的径向输运增强以及由环境湍流引起的射流内部标量波动的增加，分别导致TTI层的平均和均方根标量条件跳变比TNTI层更陡。与静态环境相比，背景湍流的平均效应是拉伸和波纹界面表面积，体现在界面径向位置的概率密度更大，零曲率表面元素的出现率更低，界面径向和法向单位矢量之间的偏差更大，扭曲度增加，分形指数的大小增加。
Abstract The effect of a zero-mean-flow turbulent ambient on the geometry of the turbulent/turbulent interface (TTI) of an axisymmetric jet is investigated and compared with the traditional turbulent/non-turbulent interface (TNTI). The ambient turbulence is generated using a random jet array. Orthogonal cross-sections of the jet subjected to different levels of ambient turbulence intensities and length scales are captured using planar laser-induced fluorescence. The enhanced radial transport of concentration from the jet core towards the interface and the increased scalar fluctuations within the jet caused by the ambient turbulence result in steeper mean and root-mean-square scalar conditional jumps across the TTI layer compared with those of the TNTI, respectively. When compared with the quiescent ambient, the mean effect of background turbulence is to stretch and corrugate the interface surface area as evident from the wider probability density of the interface radial position, the lowered occurrence of zero-curvature surface elements, the greater misalignment between the radial and normal unit vectors of the interface, the increased tortuosity and the increased magnitude of the fractal exponent.
湍流自由剪切流的湍流/非湍流界面区域中小尺度各向异性的重要性
影响因子：
2.7
作者：
Buxton O
通讯作者：
Buxton O
关于湍流/湍流界面的物理性质
影响因子：
3.7
作者：
Kankanwadi K
通讯作者：
Kankanwadi K