Characterizing length scales in the near wake of a circular cylinder using particle shadow velocimetry

The very near wake of a circular cylinder, at a Reynolds number of 61,000 was studied using two experiments in perpendicular orientations. Multiplane Particle Shadow Velocimetry (PSV), was used to obtain instantaneous velocity fields in both experiments for multiple planes perpendicular and parallel to the span of the cylinder. For both experiments, streamwise in-plane and spanwise correlations of these velocity fields were used to determine length scales corresponding to the size of the largest turbulent eddies downstream of the circular cylinder. These length scales are compared to those obtained by hotwire and pressure measurements reported in the literature.