Wake Characteristics of Two Circular Cylinders Arranged Perpendicular to Each Other

The turbulent fluid motion established in the wake of two long, smooth circular cylinders arranged perpendicular to each other has been investigated in a steady, low-turbulence, uniform flow at Reynolds numbers of 2×104 and 2×103 (based on cylinder diameter and freestream velocity). A complex three-dimensional regime was found at the center of the configuration, the precise nature of which is dependent upon the spacing of the cylinders. If the distance between the axis of each cylinder is less than three diameters, the fluid motion in the central near wake is dominated by secondary flows associated with trailing vortices and horseshoe vortices, whereas at spacings beyond this critical value there is a considerable reduction in the influence of secondary flow. The paper examines these spacing related regimes in detail and considers the extent of the associated interference effects.