Abstract
In order to understand the aspect of the mutual interference flow from two circular cylinders, the visual observation experiment was performed. The steady case experiment was performed by making three kinds of distance ratios (L/d=1.5, 2.5 and 5.5), and seven kinds of arrangement angles(α=0, 15, 30, 45, 60, 75 and 90 degrees) into experiment parameters. The oscillating case experiment was performed by making two kinds of amplitude ratios(2α/d=0.25 and 0.5), and the oscillation frequency ratio f/f_K in 24 steps. The Reynolds number was about 640. As the result of experiment, even if the distance ratio was the same, the vortex shedding characteristics changed with arrangement angles. The mutual interference will become remarkable if the distance ratio is small. In the arrangement angle, 30 degrees and 45 degrees are carrying out mutual interference most. Even when a forced in-line oscillation was performed under the conditions in which two circular cylinders are carrying out mutual interference, it was found that a lock-in phenomenon occurs. The vortex shedding characteristic was obtained.
