小颗粒粮食介质声传播性质研究

Sound Propagation Characteristic in Small Grain

从颗粒介质模型出发,对粮食介质中声传播性质进行了研究。结果发现:小颗粒粮食介质系统声学性质与动粘滞率和热效应都有关,除了在低频和高频情况下,空气有效压缩率趋于绝热压缩率外,在中间频率范围,系统的声学性质均受热效应影响,有效压缩率变成复数值,且与空隙的形状有关;粘滞和热效应对声传播速度都产生影响,相比之下,热效应影响更大。

With kernel medium model,sound propagation characteristic in grain is studied. It shows that sound characteristic in samall grain has to do with kinematic viscosity and heat effect, apart from uesful compressibility to thermal insulation compressibility under low frequency and inertia does under high frequency, heat exchange affects sound propagation characteristic and uesful compressibility becomes complex-value with void shape. Heat effect very affects sound propagation velocity.