Spanwise scale selection in plane mixing layers
Spanwise scale selection in plane mixing layers
复制标题
平面混合图层中的展向比例选择
DOI：
10.1017/s0022112093000485
复制
发表时间：
1993
影响因子：
3.7
通讯作者：
R. Moser
中科院分区：
文献类型：
--
作者：
M. M. Rogers;R. Moser
直接数值模拟的时间演变的平面混合层经历多达三个配对已被检查的展向尺度变化的证据。所有的模拟开始于一些低波数扰动，通常来自线性稳定性理论，除了平均速度。初始三维扰动的幅度从无穷小到足够大，足以触发快速过渡到湍流。在无穷小的三维扰动下，特征展向尺度的变化所需的时间很长，需要三个或更多的配对才能完成展向尺度的加倍。更强的三维性可以产生更快的尺度变化，但也可能引发向湍流的转变。没有证据表明，从一个展向尺度上有组织的肋涡阵列到一个更大展向尺度上的类似阵列的变化。
Direct numerical simulations of temporally evolving plane mixing layers undergoing as many as three pairings have been examined for evidence of spanwise scale change. All simulations were begun from a few low-wavenumber disturbances, usually derived from linear stability theory, in addition to the mean velocity. The amplitude of the initial three-dimensional disturbances varied from infinitesimal to large enough to trigger a rapid transition to turbulence. The time required for a change of characteristic spanwise scale with infinitesimal three-dimensional disturbances was found to be very long, requiring three or more pairings to complete a doubling of the spanwise scale. Stronger three-dimensionality can produce more rapid scale changes, but it is also likely to trigger transition to turbulence. No evidence was found for a change from an organized array of rib vortices at one spanwise scale to a similar array at a larger spanwise scale.