基于拍频测量的二维多普勒效应实验设计

An experimental design of two-dimentional Doppler effect based on beat frequency measurement

大学物理实验中传统多普勒效应实验装置多为一维的,本文将拍频与圆周运动应用于大学物理实验,设计并制作了一种声波人耳可听且可对多普勒频移量进行定量研究的二维多普勒效应实验装置.该装置中有两个同频声源作为被测声源与参考声源.被测声源因做匀速圆周运动而发出的变频声波与参考声源的声波相干叠加后形成可闻“拍”声,由收音装置转为电信号进入示波器后形成“拍”图像,实现多普勒效应的可视可听.该实验装置拓展了研究多普勒效应的实验教学内容,具有方案新颖、优化传统实验的特点,在实验教学方面具有一定实用价值.

Most of traditional Doppler effect experimental devices used in college physics experiments are one dimensional.In this paper,by applying beat frequency and circular motion,a two-dimensional Doppler effect experimental device is designed and produced,which let sound wave listened and make a quantitative study on Doppler effect shift.The device has two sound sources of the same frequency(the measured sound source and the reference sound source).Due to make a uniform circular motion,the frequency-frequency sound wave emitted by the measured sound source and the reference one meet and superimpose to form an audible beat sound,which is converted by the radio device into an electrical signal and then accepted by an oscilloscope to form a beat image.It makes the Doppler effect audible and visible.This experimental device expands the experimental teaching contents of studying Doppler effect,features novel scheme and optimization of traditional experiment,and has certain practical value in experimental teaching.