Boundary-layer disturbances subjected to free-stream turbulence and simulation on bypass transition
Boundary-layer disturbances subjected to free-stream turbulence and simulation on bypass transition
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自由流湍流下的边界层扰动及旁路转变模拟
DOI：
10.1007/s10483-016-2111-8
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发表时间：
2016-07
期刊：
影响因子：
--
通讯作者：
Dong Ming
中科院分区：
文献类型：
--
作者：
Qin Hong;Dong Ming
与自由流湍流（FST）夹带到边界层流动中有关的现象与许多学科有关。一般认为，Orr-Sommerfeld（O-S）/Squire方程的连续谱描述了卷吸过程，因此，在模拟旁路转捩时，它们被用来确定入口条件。然而，Dong和Wu（Dong，M.和Wu，X. On continuous spectrum of the Orr-Sommerfeld/Squire equations and entrainment of free-stream vortical disturbances.Journal of Fluid Mechanics，732，616-659（2013））指出，由于忽略了非平行性，连续谱表现出若干非物理特征。他们进一步提出了一种大雷诺数渐近方法，并表明即使对于响应集中在边缘层的短波长扰动，非平行性也是一种领先阶效应。本文通过研究不可压边界层中的渐近解的演化，对渐近解进行了数值验证。结果表明，渐近解能准确地预测数值结果，这意味着后者适用于中等雷诺数。通过引入一系列这样的解决方案，作为入流扰动，通过直接数值模拟（DNS）的旁路过渡进行了研究。转捩过程，包括条纹的演变，二次不稳定模式的放大，和湍流斑的出现，与实验观察。
The phenomena associated with the entrainment of free-stream turbulence (FST) into boundary-layer flows are relevant for a number of subjects. It has been believed that the continuous spectra of the Orr-Sommerfeld (O-S)/Squire equations describe the entrainment process, and thus they are used to specify the inlet condition in simulation of bypass transition. However, Dong and Wu (Dong, M. and Wu, X. On continuous spectra of the Orr-Sommerfeld/Squire equations and entrainment of free-stream vortical disturbances.Journal of Fluid Mechanics,732, 616–659 (2013)) pointed out that continuous spectra exhibit several non-physical features due to neglecting the non-parallelism. They further proposed a large-Reynolds-number asymptotic approach, and showed that the non-parallelism is a leading-order effect even for the short-wavelength disturbance, for which the response concentrates in the edge layer. In this paper, the asymptotic solution is verified numerically by studying its evolution in incompressible boundary layers. It is found that the numerical results can be accurately predicted by the asymptotic solution, implying that the latter is adequate for moderate Reynolds numbers. By introducing a series of such solutions as the inflow perturbations, the bypass transition is investigated via the direct numerical simulation (DNS). The transition processes, including the evolution of streaks, the amplification of secondary-instability modes, and the emergence of turbulent spots, agree with the experimental observations.
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DOI：
10.2514/6.2011-3292
发表时间：
2011-06
期刊：
--
影响因子：
--
作者：
Yongmin Zhang;T. Zaki;S. Sherwin;Xuesong Wu
通讯作者：
Yongmin Zhang;T. Zaki;S. Sherwin;Xuesong Wu
DOI：
10.1007/s11433-010-0120-3
发表时间：
2010-02
期刊：
Science China Physics, Mechanics and Astronomy
影响因子：
--
作者：
M. Dong;Heng Zhou
通讯作者：
M. Dong;Heng Zhou
影响因子：
3.7
作者：
P. Ricco;Ji-sheng Luo;Xuesong Wu
通讯作者：
P. Ricco;Ji-sheng Luo;Xuesong Wu
DOI：
10.1201/9781420050288
发表时间：
1999-11
期刊：
--
影响因子：
--
作者：
T. Papanastasiou;G. Georgiou;A. Alexandrou
通讯作者：
T. Papanastasiou;G. Georgiou;A. Alexandrou
影响因子：
4.1
作者：
STEGER, JL;WARMING, RF
通讯作者：
WARMING, RF