大颗粒粮食中声传播性质研究

 从颗粒介质模型出发，对粮食中声传播性质进行了研究．结果发现：大颗粒粮食介质的声学性质与动粘滞率有关，低频下，粘滞起主要作用，高频下，惯性起主要作用．其声传播都是频散的，并且随频率增加而增加，低频时接近于正比变化，扭曲率的存在使得声速变小．

Sound propagation characteristic in grain with large kernel

With kernel medium model,sound propagation character istic in grain i s studied． It shows that sound characteristic in grain with large kernel has to do with kinematic viscosity, viscosity plays a great role under low frequency an d inertia does under high frequency． Sound propagation velocity causes frequenc y dispersion and it increases with frequency, which does in direct proportion und er low frequency, tortuosity makes sound propagation velocity reduced． 