A linear process in wall-bounded turbulent shear flows
A linear process in wall-bounded turbulent shear flows
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DOI：
10.1063/1.870437
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发表时间：
2000-07
影响因子：
4.6
通讯作者：
John Kim;Junwoo Lim
中科院分区：
文献类型：
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作者：
John Kim;Junwoo Lim
通过数值实验研究了壁面湍流剪切流中的线性过程。结果表明，线性耦合项，这增强了非正规的线性化的Navier-Stokes系统，起着重要的作用，在充分的顺应性，因此，非线性流。近壁湍流衰减没有线性耦合项。研究还表明，如果Navier-Stokes方程中没有非线性项，近壁湍流结构就不能在合适的尺度上形成，从而表明通常观察到的近壁湍流结构的形成本质上是非线性的，但其维持依赖于线性过程。线性过程的其他影响也进行了讨论。
A linear process in wall-bounded turbulent shear flows has been investigated through numerical experiments. It is shown that the linear coupling term, which enhances non-normality of the linearized Navier–Stokes system, plays an important role in fully turbulent—and hence, nonlinear —flows. Near-wall turbulence is shown to decay without the linear coupling term. It is also shown that near-wall turbulence structures are not formed in their proper scales without the nonlinear terms in the Navier–Stokes equations, thus indicating that the formation of the commonly observed near-wall turbulence structures are essentially nonlinear, but the maintenance relies on the linear process. Other implications of the linear process are also discussed.