Excitation Mechanism of Self--Induced Sloshing Caused by Horizontal Plane Jet

摘要

A self--induced sloshing is excited by flow without any other external force. In a rectangular tank having a horizontal plane jet, the 1 st or 2 nd mode sloshing grow in a certain condition of the inlet velocity and the water level. In this study, the experiment of this phenomenon was conducted and physical characteristics were examined in detail. The new sloshing conditions, i. e. "l st Stage Sloshing" and "2 nd Stage Sloshing", were discovered in a tank. The governing parameter of the sloshing growth, i. e. the modified Strouhal Number St_s, was derived approximately. When St. was nearly either 1.0 (1 st Stage) or 2 .0 (2 nd Stage), the sloshing excitation was arranged consistently. The dependency of the inlet velocity and tank geometry was revealed using St.. A sloshing mode shift or a jet mode (stage) transition was evaluated to give rise to, with varying the inlet jet velocity. Consequently, a feedback mechanism was considered to be validated, which was closed by the jet fluctuation and the sloshing motion. The overall physical oscillation mechanism of the self-induced sloshing was clarified.