The effect of spanwise wavelength of surface heterogeneity on turbulent secondary flows

Non--type behaviour of roughness when in-plane wavelength approaches the boundary layer thickness

“…2018; Yang & Anderson 2018; Wangsawijaya et al. 2020). These same studies also show that the size of the secondary flows is dependent on the spanwise length scale , with finer spanwise spacing confining the secondary flows and subsequent spanwise variations to the region closer to the wall, while when the secondary flows become space filling and the spanwise variations in the mean extend throughout the majority of the boundary layer.…”

Channel flow with large longitudinal ribs

“…Wangsawijaya et al. 2020; Zampiron et al. 2020) and this is clearly a topic that merits further work.…”

“…The dynamics of these kinds of flows compared with those in regular channels have begun to be studied (e.g. Wangsawijaya et al 2020;Zampiron et al 2020) and this is clearly a topic that merits further work. The black and red lines have d/h = 0 and 0.34, respectively, and the dashed line is the modified log-law (as in figure 2a).…”

Parametric Study on Ridges Inducing Secondary Motions in Turbulent Channel Flow

“…Recent studies show that these turbulent secondary flows alter important flow quantities such as the streamwise velocity and the skin-friction drag [2]. It is known that the secondary motion strength is strongly dependant on the spanwise structural wavelength S [3]. The present contribution presents a detailed parametric study of a channel flow with streamwise ridges, adding a systemic variation of the ridge geometry and the resulting flow topology to the present understanding of secondary flows over spanwise inhomogeneous surfaces.…”