低流速における円柱の振動と流体力

抄録

Many studies about flow induced vibration of a single cylinder have been conducted and a lot of problems were cleared. However, most of these studies are concerning to the velocity, at which the vortex resonant vibration will occur. Recently, cylinders in a high-density fluid have vibrated in a very low velocity range. Several studies have been conducted but many unknown points are remained. Vibration tests of a single cylinder in water were conducted to make the vibrations clear. These tests revealed that the vibration starts at the reduced velocity of about 1.4 and ceases at the reduced velocity of about 4.1. Most of the vibrations are in drag direction but some of them vibrated in locus of a character 8 of Arabic mumerals. Unsteady fluid dynamic forces acting on the cylinder at the low velocity were also measured and ensured the existence of the vibrations in a low flow velocity.