Disturbance growth rate in turbulent wall flows
Disturbance growth rate in turbulent wall flows
复制标题
湍流壁流中的扰动增长率
DOI：
10.1134/s0015462809050032
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发表时间：
2009
期刊：
影响因子：
0.9
通讯作者：
Nikitin N
中科院分区：
文献类型：
--
作者：
Nikitin N
对湍流壁流中的扰动发展进行了数值研究。考虑了圆管和平面流道中的流动。在沿主流具有周期性的条件下，对Navier-Stokes方程进行时间积分，直到得到统计上平稳的“湍流”流型。然后对解进行扰动，通过比较并行计算的有扰动和无扰动两种解来确定扰动的进一步演化。结果表明，在线性阶段，解的平均发散性为指数型。研究的主要结果是，由壁面时间尺度归一化的小扰动增长率被证明是恒定的，即既不取决于所考虑的范围内的雷诺数，也不取决于流动的类型：λ+≈0.021。对扰动增长率的估计与前人关于下游扰动增长的结果以及对平面渠道湍流计算的最高Lyapunov指数的估计是一致的。
Disturbance development in turbulent wall flows is numerically investigated. The flows in a circular tube and in a plane channel are considered. The Navier-Stokes equations subjected to the condition of periodicity along the main flow are integrated in time until a statistically stationary “turbulent” flow regime is attained. Then the solution is disturbed and the further evolution of the disturbance is determined by comparing the two solutions, i.e., with and without the disturbance, which are calculated in parallel. It is shown that in the linear stage on average the solutions diverge exponentially. The main result of the study is that the small disturbance growth rate normalized by the wall time scale turns out to be constant, that is, dependent on neither the Reynolds number on the range considered nor the type of the flow: λ+≈ 0.021. The estimate of the disturbance growth rate is consistent with the previously obtained results concerning downstream disturbance growth and the estimate for the highest Lyapunov exponent calculated for turbulent flow in a plane channel.
影响因子：
3.7
作者：
L. Keefe;P. Moin;John Kim
通讯作者：
John Kim