ダクテッドファンの回転音響モードの能動制御

概要

論文の詳細を見る
This paper describes fundamental experiments on active noise control applied to a ducted model fan. An acoustic modal cancellation is adopted for dealing with spinning modes in fan noise. Two experiments were carried out to verify the feasibility of reducing spinning modes. At first, the modal cancellation of single spinning mode was demonstrated by use of a modal fan as a noise source and acoustic driver units as anti-phased secondary sound sources. The spinning mode in a first blade passage frequency was attenuated by as much as 15 dB with little spillover of the secondary sound. Next, modal cancellation of multimodes was assessed by two approaches of simultaneously suppressing different spinnng modes. One approach is to separate secondary sound sources so that each sound source relaases corresponding spinning mode. The other is to superpose control signals for spinning modes and to release the superposed signal through single sound source. As a result, spinning modes in both a fundamental blade passage frequency and the higher harmonics could be suppressed with little spillover of secondary sound.
社団法人日本機械学会の論文
2000-01-25