Hodgson Murray, Guo Jingnan, Germain Pierre
School of Occupational and Environmental Hygiene and Department of Mechanical Engineering, University of British Columbia, 3rd Floor, 2206 East Mall, Vancouver, British Columbia V6T 1Z3, Canada.
J Acoust Soc Am. 2003 Dec;114(6 Pt 1):3201-10. doi: 10.1121/1.1628248.
Engine run-ups are part of the regular maintenance schedule at Vancouver International Airport. The noise generated by the run-ups propagates into neighboring communities, disturbing the residents. Active noise control is a potentially cost-effective alternative to passive methods, such as enclosures. Propeller aircraft generate low-frequency tonal noise that is highly compatible with active control. This paper presents a preliminary investigation of the feasibility and effectiveness of controlling run-up noise from propeller aircraft using local active control. Computer simulations for different configurations of multi-channel active-noise-control systems, aimed at reducing run-up noise in adjacent residential areas using a local-control strategy, were performed. These were based on an optimal configuration of a single-channel control system studied previously. The variations of the attenuation and amplification zones with the number of control channels, and with source/control-system geometry, were studied. Here, the aircraft was modeled using one or two sources, with monopole or multipole radiation patterns. Both free-field and half-space conditions were considered: for the configurations studied, results were similar in the two cases. In both cases, large triangular quiet zones, with local attenuations of 10 dB or more, were obtained when nine or more control channels were used. Increases of noise were predicted outside of these areas, but these were minimized as more control channels were employed. By combining predicted attenuations with measured noise spectra, noise levels after implementation of an active control system were estimated.
发动机试车是温哥华国际机场定期维护计划的一部分。试车产生的噪音传播到附近社区，干扰居民。有源噪声控制是一种相对于被动方法（如隔音罩）而言潜在成本效益更高的替代方案。螺旋桨飞机产生的低频音调噪声与有源控制高度匹配。本文对使用局部有源控制来控制螺旋桨飞机试车噪声的可行性和有效性进行了初步研究。针对不同配置的多通道有源噪声控制系统进行了计算机模拟，旨在采用局部控制策略降低相邻居民区的试车噪声。这些模拟基于先前研究的单通道控制系统的最优配置。研究了衰减区和放大区随控制通道数量以及源/控制系统几何形状的变化。在这里，飞机使用一个或两个声源进行建模，具有单极或多极辐射模式。同时考虑了自由场和半空间条件：对于所研究的配置，两种情况下的结果相似。在两种情况下，当使用九个或更多控制通道时，都获得了局部衰减为10分贝或更高的大三角形安静区。预计在这些区域之外会有噪声增加，但随着使用更多控制通道，这种增加被最小化。通过将预测的衰减与测量的噪声频谱相结合，估算了有源控制系统实施后的噪声水平。
