Third Symposium on Turbulence and Shear Flow Phenomena
DOI: 10.1615/TSFP3
STRUCTURE OF TURBULENT CHANNEL FLOW WITH SQUARE BARS ON ONE WALL
pages 123-128
DOI: 10.1615/TSFP3.210
RÉSUMÉ
The organised motion in a turbulent channel flow with a succession of square bars on the bottom wall has been investigated using direct numerical simulations. Four values (1,3,7,19) of the ratio ω/k, where k is the bar height and ω is the longitudinal separation between consecutive bars have been examined in detail. Relative to a smooth surface, the streamwise extent of the near-wall structures is decreased while their spanwise extent is increased. As ω/k increases, the coherence decreases in the streamwise direction and increases in the spanwise direction. Reynolds stresses and their anisotropy invariants show a closer approach to isotropy over the rough wall than over a smooth wall.