Visualization of Three-dimensional Wake of a Two-dimensional Circular Cylinder

Abstract

The three-dimensionality of the wake of a two-dimensional circular cylinder is investigated by flow visualization experiments at low Reynolds numbers (Re-100). The experiment Ls conducted in a towing water tank with the aid of white dye as a tracer for visualization. The results are rather dependent on the initial status of the fluid, from which the cylinder starts to be towed in the tank. However, the three-dimensionality is always more or less discernible at low Reynolds numbers where the wake vortices seem to remain laminar until the decay at downstream. And this is still the case in the middle part of the cylinder span where the so-called end effects are considered as negligible.