Secondary flow and streamwise vortices in three-dimensional staggered wavy-wall turbulence

The present paper simplifies the naturally formed dunes (riverbeds) as large-scale three-dimensional staggered wavy walls to investigate features of accompanying secondary flows and streamwise vortices via large-eddy simulation. A comparison between swirling strength mean velocities suggests where a flow induces upwash or downwash motions. Moreover, we propose pseudo-convex wall mechanism interpret directionality flow. centrifugal instability criterion is then used reveal generation vortices. Based on these analytical results, found that are generated in separation reattachment points both characteristic longitudinal–vertical horizontal cross-sections, which related curvature effect turbulent shear layer. Furthermore, maximum Görtler number characterized by ratio viscous effects that, for fixed spanwise- streamwise-wavelength cases, strongest occurring cross-section gradually dominates with increases amplitude. similar trend cases varied spanwise wavelength can also be found. It more readily transverse around crest near when equals 1.