A211 プレートから放射される離散周波数音の基本特性について

概要

論文の詳細を見る
In order to investigate the aerodynamic sound generated from plates which have various chord-to-thickness ratios (c/t=1∿35) and four types of edge shapes consist of semi-circular and square, wind tunnel test is conducted in our low noise wind tunnel with □200mm×200mm nozzle. In this study, some basic characteristics of aerodynamic sound, which are (i) Peak Strouhal Number (St), (ii) effect of edge shapes on priority of Peak SPL, (iii) increase in Peak SPL with wind velocity, (iv) radiation directivity, are investigated. As a result, it is found that St and priority of Peak SPL depend on leading edge shape and Peak SPL isn't proportional to U^6 under the condition that chord-to-sound wave length ratio (c/λ) becomes greater than 1/3. Moreover, the radiation directivity from the dipoles is biased toward upper stream side, as c/λ becomes large regardless of edge shapes.
日本流体力学会の論文
2000-07-25