Linearised Reynolds-averaged predictions of secondary currents in turbulent channels with topographic heterogeneity
Linearised Reynolds-averaged predictions of secondary currents in turbulent channels with topographic heterogeneity
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具有地形异质性的湍流通道中二次电流的线性雷诺平均预测
DOI：
10.1017/jfm.2022.478
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发表时间：
2022
影响因子：
3.7
通讯作者：
Zampino G
中科院分区：
文献类型：
--
作者：
Zampino G
本文提出了一种基于线性化雷诺平均纳维-斯托克斯方程的快速预测工具，用于研究湍流通道中由与流无关的表面地形调制产生的二次流。该工具是通过将Reynolds-average动量方程与Spalart-Allmaras输运方程耦合得到的，该输运方程用于紊流涡流粘度，使用雷诺应力的非线性本构关系来正确捕获二次运动。描述任意表面调制的稳定流动响应的线性化方程是通过假设表面调制是浅的推导出来的。由于方程是线性的，因此叠加原理成立，任意调制引起的流动响应可以通过在多个跨长尺度上对正弦调制得到的初等响应进行适当组合得到。该工具允许快速探索大参数空间，表征先前在文献中检查过的结构表面地形。这里考虑了具有正弦壁和纵向矩形脊的通道。对于正弦壁面，在内部和外部单元的两个跨展波长尺度上分别观察到较大的响应，反映了瞬态生长分析中观察到的湍流剪切流的放大机制。对于纵向矩形脊，该模型表明，使用脊宽和脊间间隙来代替文献中提出的其他组合，有助于分析响应和解释次级结构的拓扑结构。
A rapid predictive tool based on the linearised Reynolds-averaged Navier–Stokes equations is proposed in this work to investigate secondary currents generated by streamwise-independent surface topography modulations in turbulent channel flow. The tool is derived by coupling the Reynolds-averaged momentum equation to the Spalart–Allmaras transport equation for the turbulent eddy viscosity, using a nonlinear constitutive relation for the Reynolds stresses to capture correctly secondary motions. Linearised equations, describing the steady flow response to arbitrary surface modulations, are derived by assuming that surface modulations are shallow. Since the equations are linear, the superposition principle holds and the flow response induced by an arbitrary modulation can be obtained by combining appropriately the elementary responses obtained over sinusoidal modulations at multiple spanwise length scales. The tool permits a rapid exploration of large parameter spaces characterising structured surface topographies previously examined in the literature. Here, channels with sinusoidal walls and with longitudinal rectangular ridges are considered. For sinusoidal walls, a large response is observed at two spanwise wavelengths scaling in inner and outer units respectively, mirroring the amplification mechanisms in turbulent shear flows observed from transient growth analysis. For longitudinal rectangular ridges, the model suggests that the analysis of the response and the interpretation of the topology of secondary structures is facilitated when the ridge width and the gap between ridges are used instead of other combinations proposed in the literature.
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DOI：
10.1016/j.ijheatfluidflow.2019.108518
发表时间：
2020-02
影响因子：
2.6
作者：
A. Stroh;K. Schäfer;P. Forooghi;B. Frohnapfel
通讯作者：
A. Stroh;K. Schäfer;P. Forooghi;B. Frohnapfel
影响因子：
2.7
作者：
Abderrahaman-Elena, Nabil;Garcia-Mayoral, Ricardo
通讯作者：
Garcia-Mayoral, Ricardo
影响因子：
3.7
作者：
T. Medjnoun;C. Vanderwel;B. Ganapathisubramani
通讯作者：
T. Medjnoun;C. Vanderwel;B. Ganapathisubramani
湍流对体积力的线性响应：涡粘模型与 DNS 的比较
影响因子：
3.7
作者：
S. Russo;P. Luchini
通讯作者：
P. Luchini
影响因子：
3.7
作者：
A. Busse;N. Sandham
通讯作者：
A. Busse;N. Sandham