对膜簧片型汽笛频率影响因素的研究

INFLUENCE FACTORS TO FREQUENCY OF BALLOONWHISTLE BASED ON MEMBRANE REEDS

本文对汽笛频率影响因素进行了理论与实验探究,在汽笛薄膜振动动力学方程中引入了附加质量的概念,并建立了薄膜振动模型。根据该模型研究了薄膜面密度,管子的长度与半径,容器的半径和进气质量流速对汽笛发声频率的影响;通过声音在管道内传播的波动方程给出了管内空气柱振动模型。实验研究结果表明,对声音信号基频的主要影响因素包括薄膜参数和管子参数。当薄膜张力增大时,声音信号的基频增大;但是当薄膜半径和薄膜面密度增大时,声音信号的基频却减小。当进气速率增大时,声音信号的基频增大;但是,当管子的长度和半径增大时,声音信号的基频却减小。截止目前,该项研究在国内外鲜见研究报道。

The factors to influence the frequency of the balloon whistle were studied theoretically and experimentally.The additional mass was considered in the dynamic vibration equation,and the film vibration model was presented.The influences of the film density,the length and radius of the tube,the radius of the container,and the inlet air mass spend to the frequency of the balloon whistle were studied based on the film vibration model.The air column vibration model was derived from the wave equation of sound propagation in the tube.The experimental results showed that the main influence factors to the base frequency are the film and tube parameters.The base frequency increased with the film tension increasing,but decreased with the film radius and surface density increasing.The base frequency increased with the inlet air mass speed increasing,but decreased with the tube length and radius increasing.The similar studies were less reported worldwide till now.