Effect of Spacing between Two Adjoining Circular Cylinders on Flow around Two-Dimensional Circular Cylinder Rows by Elastic Support. (3rd Report. Two Rows in Side-by-Side Arrangement.

Abstract

In this paper we describe the effect of spacing between two adjoining circular cylinders on flow around two rows of two-dimensional circular cylinder bundles supported by wires. The experiment was carried out in an N.P.L. blow-down-type wind tunnel with a working section of 500mm×500mm×2000mm, and a Reynolds number of 9.4×103. The frequency of vortex shedding from the circular cylinder, the displacement of the vibrating circular cylinder, and the mean time and fluctuating surface pressure distributions on the circular cylinder were measured. The results were compared with those for the case of a fixed support. Consequently it was found that (i) vortex shedding from circular cylinders occurs in the range of spacing ratio S/D≥2, (ii) fluid elastic vibration occurs in the range of S/D<2 for the first row and S/D<2.3 for the second row, and (iii) the variation of fluctuating drag coefficient and fluctuating lift coefficient corresponds to that of displacement of a vibrating cylinder.