円形噴流・直管系での自励振動および共鳴に対する金網の影響

概要

論文の詳細を見る
The self-sustained oscillation is known to be excited by an axisymmetric jet impinging upon the sharp-leading edge of a ring. When a finite length of pipe, instead of a ring, is placed in a straight line with the jet axis, longitudinal resonant modes of the pipe are produced under a certain flow and geometerical conditions. In this paper, the influence of the inserted screen on the self-sustained oscillation and resonance of the pipe column oscillation are studied when a screen is placed between the nozzle exit and the ring or the pipe. Two patterns of the feedback loop are formed by the interaction between the vortical structure in the shear layer and the screen, or by the interaction between the former and the ring or the pipe. In the case of the pipe there are three frequency modes, namely oscillations in the two feedback loops and a resonant mode of the pipe. The resonance of the pipe is excited or suppressed according to the relationship among the three modes. When the screen is placed near the nozzle exit, the screen prevents the self-sustained oscillation and the resonance of the pipe dose not appear.
一般社団法人日本機械学会の論文
1998-03-25