著者

木村 貴裕 高山 佳久 維本 信哉 石川 諭

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会九州支部講演論文集

巻号頁・発行日

vol.2012, pp.103-104, 2012

著者

久野 翔太郎 石川 諭 雉本 信哉 木庭 洋介

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.854, pp.17-00305-17-00305, 2017 (Released:2017-10-25)

参考文献数

13

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Several adaptive feedforward control methods have been proposed in previous research on active noise control. In those methods, noise control is achieved by adding in a reverse-phase control sound of the same amplitude to noise near an error microphone. Because this method is aimed at controlling only noise near the error microphone, the control area is inherently narrow. Here, we propose an alternative method of noise control for an entire closed space. The proposed method is based on state feedback control and modeling of the acoustic space by the concentrated-mass model. The acoustic space is modeled as masses, connecting springs, and connecting dampers. Further, a loudspeaker as control source is also modeled as a mass-spring-damper system. We previously reported a method for simple one-dimensional acoustic space control. In this paper, we show the design of a control system for two-dimensional acoustic spaces. The acoustic space and loudspeakers are modeled in a concentrated-mass model, and the state feedback control system is realized as a Kalman filter with pole placement. The number of degrees of freedom is reduced by using modal analysis, which reduces the computation time of the controller. Experiments and numerical simulation of the coupled system were conducted to confirm the validity of the analysis model. Noise in the acoustic space was experimentally controlled, with the finding that noise in the entire acoustic space was reduced around the resonance frequencies. Furthermore, the limit of the control effect are considered within the proposed system.

著者

石川 諭 近藤 孝広 松崎 健一郎 榎元 啓允

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.80, no.814, pp.DR0166-DR0166, 2014 (Released:2014-06-25)

参考文献数

10

被引用文献数

1

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A pressure wave generated by a compressor propagates in an air-conditioner piping system and causes a noise problem. The flow condition in the air-conditioner piping system becomes often a one-component two-phase flow, and attenuation of the pressure wave in the one-component two-phase flow is larger than the two-component two-phase flow because of the effect of the mass transfer. It is also important for the safety of nuclear reactors to understand the characteristic of pressure wave problems in the one-component two-phase flow. In this paper, we propose a concentrated mass model to analyze the pressure wave problems in the one-component two-phase flow. This model consists of masses, connecting springs, connecting dampers, and nonlinear base support dampers. The connecting spring and the connecting damper are derived from the compressibility of the gas phase and the effect of the mass transfer when the phase-change occurs. And the nonlinear base support damper is derived from the pipe friction. Additionally, an experiment on an air-conditioner piping system is performed, and the experimental results are compared with the numerical result in order to confirm the validity of the model. The numerical computational results agree very well with the experimental results. Especially, the attenuation of the pressure wave generated by the phase-change is numerically reproduced. Therefore, it is concluded that the proposed model is valid for the numerical analysis of the pressure wave problem in the two-phase flow.