摘要
内流场和调制面积的准确测量是大功率调制气流声源实验研究中的关键问题,传统测量技术具有明显的局限性。采用光电检测方法以实现速度场和声源调制面积的非接触测量,通过粒子速度成像技术获取声源气路系统中的速度场,通过CCD系统实现对声源振动系统位移输出和调制面积变化的实时监控。实验结果与数值模型结果的比较验证了测试方法的可行性。速度场结果表明,典型工况下受限射流靠近内侧壁面,流动分离出现在外侧壁面附近,声源内部形成的剪切层位于主流与回流之间。音圈位移实测结果说明所选择的驱动参数可实现对喷口射流的满调制。
Internal flow and modulation area measurements are crucial for the experimental study of air-modulated speaker （AMS）. Complex physical process such as unsteady flow, high frequency vibration and flow-structure interaction exists in the narrow space of vocal tract. In this paper, contacttess opto-electronic testing methods are utilized to record the velocity field and modulation area data. Velocity result in steady flow of 2D AMS model is obtained by using particle image velocimetry （PIV）, while real time monitor of the modulation area is carried out by the displacement testing system based on CCD. Corresponding testing results are compared with the CFD and FEM simulation results in order to validate the methods feasibility. Dominant steady flow characteristics are observed including pressure recovery, flow separation on the out wall and vortex appearance in the shear layer between the main and reverse flow. Modulation area testing results are used to investigate the driving signal parameters corresponding to the full-modulation status of voice coil component.
出处
《光学与光电技术》
2010年第5期61-66,共6页
Optics & Optoelectronic Technology
关键词
测量
调制气流声源
粒子图像测速
电荷耦合器件
measurement
air-modulated speaker
particle image velocimetry
charge coupled device
