Resolvent-based predictions for turbulent flow over anisotropic permeable substrates
Resolvent-based predictions for turbulent flow over anisotropic permeable substrates
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基于溶剂的各向异性渗透基底上的湍流预测
DOI：
10.1017/jfm.2020.1169
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发表时间：
2021
影响因子：
3.7
通讯作者：
Luhar, M.
中科院分区：
文献类型：
--
作者：
Chavarin, A.;Gómez-de-Segura, G.;García-Mayoral, R.;Luhar, M.
最近的模拟表明，流向优先的多孔材料有可能减少壁面湍流中的阻力（戈麦斯-德-塞古拉和加西亚-马约拉尔，《流体机械杂志》。，第875卷，2019年，pp. 124-172）。本文扩展了求解公式，研究了各向异性渗透性基质对湍流槽道流动的影响。在此预解式下，将傅立叶变换的Navier-Stokes方程解释为线性强迫响应系统。非线性项被认为是系统中引起速度和压力响应的内生强迫。一个基于增益的分解的强制响应传递函数-预解算子-识别响应模式（预解模式），已知重现重要的结构和统计特征的壁边界湍流。在这个框架中引入的渗透性基板的效果，使用体积平均的Navier-Stokes方程和广义形式的达西定律。具有高流向渗透率和低展向渗透率的基板被发现抑制的强迫响应增益的预解模式，作为一个替代的充满活力的近壁周期。这种模式增益的减少被证明是一致的理论预测和数值模拟中观察到的减阻趋势。模拟结果表明，减阻是有限的展向辊类似开尔文-亥姆霍兹涡的出现超过壁面法向渗透率的阈值。预解式框架还预测了这种充满活力的展向相干辊出现的条件。这些研究结果表明，一组有限的预解模式可以作为构建模块的计算效率高的模型，使被动湍流控制的可渗透基板的设计和优化。
Recent simulations indicate that streamwise-preferential porous materials have the potential to reduce drag in wall-bounded turbulent flows (Gómez-de-Segura & García-Mayoral, J. Fluid Mech., vol. 875, 2019, pp. 124–172). This paper extends the resolvent formulation to study the effect of such anisotropic permeable substrates on turbulent channel flow. Under the resolvent formulation, the Fourier-transformed Navier–Stokes equations are interpreted as a linear forcing–response system. The nonlinear terms are considered the endogenous forcing in the system that gives rise to a velocity and pressure response. A gain-based decomposition of the forcing–response transfer function – the resolvent operator – identifies response modes (resolvent modes) that are known to reproduce important structural and statistical features of wall-bounded turbulent flows. The effect of permeable substrates is introduced in this framework using the volume-averaged Navier–Stokes equations and a generalized form of Darcy's law. Substrates with high streamwise permeability and low spanwise permeability are found to suppress the forcing–response gain for the resolvent mode that serves as a surrogate for the energetic near-wall cycle. This reduction in mode gain is shown to be consistent with the drag reduction trends predicted by theory and observed in numerical simulations. Simulation results indicate that drag reduction is limited by the emergence of spanwise rollers resembling Kelvin–Helmholtz vortices beyond a threshold value of wall-normal permeability. The resolvent framework also predicts the conditions in which such energetic spanwise-coherent rollers emerge. These findings suggest that a limited set of resolvent modes can serve as the building blocks for computationally efficient models that enable the design and optimization of permeable substrates for passive turbulence control.
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影响因子：
1.9
作者：
M. Luhar;Ati S. Sharma;B. McKeon
通讯作者：
M. Luhar;Ati S. Sharma;B. McKeon
影响因子：
2.7
作者：
Abderrahaman-Elena, Nabil;Garcia-Mayoral, Ricardo
通讯作者：
Garcia-Mayoral, Ricardo
预测湍流通道流对变相反对控制的响应：溶解分析作为流量控制设计的工具
影响因子：
2.7
作者：
Simon S. Toedtli;M. Luhar;B. McKeon
通讯作者：
B. McKeon
影响因子：
3.7
作者：
C. Manes;D. Poggi;L. Ridolfi
通讯作者：
C. Manes;D. Poggi;L. Ridolfi
影响因子：
3.7
作者：
Jiménez, J;Pinelli, A
通讯作者：
Pinelli, A