MECHANISM OF WIND-INDUCED ROTATION IN FERRIS WHEEL GONDOLAS

Abstract

 The purpose of this study is to elucidate the mechanism of the rotational motion induced by strong wind in Ferris wheel gondolas. It is found that this rotational motion is caused by the galloping oscillation induced by the wind blowing to the front face of a gondola. This galloping oscillation is amplified with increasing wind speed, and changes into the rotational phase when the angular amplitude exceeds 180 degrees. The induced galloping converges to steady-state amplitude, while it is necessary to exceed a threshold of the gondola response amplitude to induce the galloping. This steady-state amplitude is determined by wind speed, and especially the angular velocity amplitude is proportional to wind speed. This proportional relation is shown in the rotational phase as well as the oscillatory phase.