碳纳米管薄膜扬声器设计及有源噪声控制

摘要

碳纳米管薄膜扬声器是近几年发展起来的一种基于热声效应的新型扬声器.以探究碳纳米管薄膜扬声器作为次级声源的可行性为目的,研究了碳纳米管薄膜远场声压及主要影响因素,进而设计出可调节的并联结构薄膜扬声器;首次提出将碳纳米管薄膜应用于有源噪声控制中,将其作为次级声源构建有源消声模型,以初、次级声源的总声功率最小为目标,推导出薄膜声源的最优控制电压;设计了5个不同的薄膜扬声器作为次级声源对单极子初级声源实施控制,计算有源控制效果,分析控制效果的主要影响因素.%Carbon nanotube film loudspeaker is a new kind of speaker constituted by the superaligned carbon nanotubes based on thermoacoustic effect in recent years.For the purpose of probing the feasibility of carbon nanotube film loudspeaker as secondary sound source,the main factors which affect the far-field sound pressure of carbon nanotube film are analyzed.According to the characteristics,a simple and adjustable carbon nanotube film loudspeaker is designed to facilitate the practical application.The application of carbon nanotube film loudspeaker in active noise control has been proposed for the first time in this paper and the model of active noise control is constructed with the film as secondary source.For the target of the least total sound power of primary and secondary source,the optimal control voltage of the film is sovled.Five different carbon nanotube film loudspeakers are designed to control monopole acoustic radiation as the secondary source respectively.The active control effect is calculated and the main factors are analyzed.