本文在验证了光声效应实验的可行性和正确性的基础上,逐一通过改变某一个变量来探究影响光声效应的因素,并利用Cool Edit Pro V2.1等声音分析软件将产生的声音收录起来进行定量的测量,分析影响光声效应实验产生声音音量和频率和相关影...本文在验证了光声效应实验的可行性和正确性的基础上,逐一通过改变某一个变量来探究影响光声效应的因素,并利用Cool Edit Pro V2.1等声音分析软件将产生的声音收录起来进行定量的测量,分析影响光声效应实验产生声音音量和频率和相关影响因素的关系。同时,设计光声信号产生装置,并搭建了光声信号测量系统,进而对该装置进行了进一步研究,最终设计出了基于光声效应的"光琴"演示装置。展开更多
Thermoacoustically-driven pulse tube cooler can provide cryogenic cooling power with no moving com-ponents. Up to now, pulse tube cooler is directly coupled with the thermoacoustic engine and obtainable pressure ratio...Thermoacoustically-driven pulse tube cooler can provide cryogenic cooling power with no moving com-ponents. Up to now, pulse tube cooler is directly coupled with the thermoacoustic engine and obtainable pressure ratio for the pulse tube cooler is limited by the capability of the ther-moacoustic engine. The authors propose here the concept of acoustic amplifier, which is actually a long tube connecting the engine with the pulse tube cooler. Theoretical calculation shows that suitable length and diameter of the tube can lead to a pressure wave amplification effect which means that pressure wave amplitude coming from the thermoacoustic engine can be much amplified to drive the pulse tube cooler. Based on this, a 2.8 m long copper tube with 8 mm inner diameter is used as the acoustic amplifier in experiments. The experimental results show that due to the amplification effect, pressure wave amplitude at the inlet of the pulse tube cooler is over 2.5 times of that at the engine outlet. Typically, with 1.67 kW heating power, the pressure ratio provided by the engine is 1.11 while at the inlet of the pulse tube cooler the pressure ratio is 1.32, which leads to a lowest no-load temperature of 65.7 K.展开更多
文摘本文在验证了光声效应实验的可行性和正确性的基础上,逐一通过改变某一个变量来探究影响光声效应的因素,并利用Cool Edit Pro V2.1等声音分析软件将产生的声音收录起来进行定量的测量,分析影响光声效应实验产生声音音量和频率和相关影响因素的关系。同时,设计光声信号产生装置,并搭建了光声信号测量系统,进而对该装置进行了进一步研究,最终设计出了基于光声效应的"光琴"演示装置。
基金supported by the Chinese Academy of Sciences(Project Number:KJCX2-SW-W12-l).
文摘Thermoacoustically-driven pulse tube cooler can provide cryogenic cooling power with no moving com-ponents. Up to now, pulse tube cooler is directly coupled with the thermoacoustic engine and obtainable pressure ratio for the pulse tube cooler is limited by the capability of the ther-moacoustic engine. The authors propose here the concept of acoustic amplifier, which is actually a long tube connecting the engine with the pulse tube cooler. Theoretical calculation shows that suitable length and diameter of the tube can lead to a pressure wave amplification effect which means that pressure wave amplitude coming from the thermoacoustic engine can be much amplified to drive the pulse tube cooler. Based on this, a 2.8 m long copper tube with 8 mm inner diameter is used as the acoustic amplifier in experiments. The experimental results show that due to the amplification effect, pressure wave amplitude at the inlet of the pulse tube cooler is over 2.5 times of that at the engine outlet. Typically, with 1.67 kW heating power, the pressure ratio provided by the engine is 1.11 while at the inlet of the pulse tube cooler the pressure ratio is 1.32, which leads to a lowest no-load temperature of 65.7 K.
