振動弾性板流れ発生機の特性に関する実験研究

摘要

Flow characteristics by a Vibrating Elastic Plate Flow Generator (VEPFG) was investigated experimentally. The device was a plate made vibrated perpendicularly to itself at the leading edge. The flow was found to be generated for a narrow range of frequency around the resonance frequency, with its maximum at the resonance frequency. The induced flow rate and its efficiency were experimentally determined. The performances were relatively low compared with the analytically expected ones. The efficiency turned out to be of 10 per cent. On the basis of the visualized flow patterns, one of possible causes for the difference is attributed to the existence of unsteady large-scale discrete vortices at both the trailing edge and the side edges. The side-edge vortices are seen to reduce drastically the induced flow rate by the factor of more than two.%振動弾性板流れ発生機（Vibrating Elastic Plate Fluid Generator略称VEPFG）は弾性薄板を加振すること により流れを発生させる装置で，古くはうちわや扇 子，最近では圧電フアン，攪拌用スターラ，実験的に はボートの推進器，等に利用され始めている．また 魚類や水棲動物の尾びれ推進のメカニズムにも共通 の部分がある．著者等はこれを流体機械として活用 することを目指して研究を続けている．