Visualization of separated shear layer streaks generated by micro vortex generators based on tomographic PIV

Three-dimensional flow fields downstream of micro VGs in backward-facing step (BFS) flow are experimentally investigated by time-resolved tomographic particle image velocimetry (PIV). Streaks within the separated shear layer are visualized by time-averaged velocity field. Complex streamwise vorticity fields are analyzed by proper orthogonal decomposition (POD) and coherent vortex structures are reconstructed by predominant POD mode pairs.Graphical Abstract