并联石墨烯热声激励器的声场建模及实验研究

Acoustic field modeling and measurement of the parallel graphene based thermo-acoustic actuator

  • 摘要: 主动流动控制技术是提升航空航天飞行器气动特性的有效手段,其中激励器是这些控制技术的核心组件,如等离子体激励器、合成射流激励器以及振荡射流激励器等。本文提出了一种基于热声效应的并联石墨烯热声激励器,该激励器具有结构简单、输入功率低、控制频率宽以及结构适应性强等优点,能够适应飞行器各种复杂曲壁面安装环境和变飞行工况,具有良好的应用前景。具体而言,该热声激励器利用石墨烯材料比热容极低和热导率高的特性,通过焦耳加热原理向周围空气辐射周期性的声场以进行声激励控制。首先,通过热声理论对石墨烯热声激励器进行声场建模,建模中加入了组合声源叠加原理,优化了声波相位差和声场指向性计算方法;其次,改进了石墨热声烯激励器的电路连接方式,采用并联石墨烯薄膜有效提升了声场声压幅值;最后,搭建了石墨烯热声激励器的声压测试平台,验证并研究了并联石墨烯热声激励器的声场特征,分析了输入功率、频率、测试距离等因素的影响。

     

    Abstract: The active flow control technology is an effective method to improve the aerodynamic characteristics of aerospace vehicles, in which actuators are the core of these control technologies such as plasma actuator, synthetic jet actuator and oscillating jet actuator. Present study proposes a parallel graphene actuator based on the thermo-acoustic effect. The actuator has the advantages of simple structure, low input power, wide controlling frequency and strong structural adaptability. It can adapt to various complex curved wall installations of aircraft environment and variable working conditions, resulting in a good application prospect. Specifically, the thermo-acoustic actuator utilizes the extremely low specific heat capacity and high coefficient of heat conductivity characteristics of graphene materials. Through the Joule heating principle, the graphene films can radiate a periodic sound field to the surrounding air for acoustic excitation control. According to this principle, firstly this paper uses the thermo-acoustic theory to model the sound field of the graphene actuator, adds the principle of combined sound source superposition to the modeling, and optimizes the computation method of acoustic wave phase difference and sound field directivity. Secondly, it improves the circuit connection method of the parallel graphene actuator films so that it effectively increases the sound pressure amplitude of the sound field. Finally, by establishing a sound pressure test platform in a semi-anechoic chamber room and analyzing the influence of input power, frequency, test distance and other factors on output sound pressure, this paper studies and verifies the sound field of the parallel graphene thermo-acoustic actuator.

     

/

返回文章
返回