The structure of turbulent flow in a rectangular channel containing a cylindrical rod - Part 1: Reynolds-averaged measurements

Flow visualization and hot-wire anemometry were used to investigate the isothermal velocity field in a rectangular channel containing a single cylindrical rod, focussing on the gap region between the rod and a plane wall. Measurements reported in this paper, which is part 1 of a two-part series, include the variations of the Reynolds-averaged mean velocity, wall shear stress and turbulent stresses. The presence of large-scale, quasi-periodic structures in the vicinity of the gap, for a range of gap widths, has been demonstrated through flow visualization, spectral analysis and space-time correlation measurements. The above measurements appear to be compatible with the field of a street of three-dimensional, counter-rotating vortices, whose convection speed and streamwise spacing have been determined as functions of the gap width. (C) 2000 Elsevier Science Inc. All rights reserved.