失谐驻波管及其极高纯净驻波场性质的研究  

Dissonant standing-wave tube and the extremely nonlinear pure standing wave field

作　　者：闵琦[1,2] 刘克[1] 

机构地区：[1]中国科学院声学研究所噪声与振动重点实验室,北京100190 [2]红河学院,蒙自661100

出　　处：《物理学报》2011年第2期363-371,共9页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:10574135);中国科学院三期知识创新工程重要方向(批准号:KJCX2-YW-W02)资助的课题~~

摘　　要：由直径不同的两级直圆管连接而成的两级突变截面驻波管具有失谐性,即高阶共振频率不是一阶共振频率的整数倍.两级突变截面驻波管的失谐性质能够很好地抑制一阶共振频率激励下的大振幅非线性驻波畸变产生的高次谐波,从而获得大振幅纯净驻波场.通过对两级突变截面驻波管失谐性质的研究,采用大功率扬声器正接等措施,利用两级突变截面驻波管的失谐性质在一阶共振频率激励下获得了184dB的极高纯净驻波场,并对二至五阶共振频率激励下的声场进行了相应的实验研究.在二阶、四阶共振频率激励下分别获得了180和166dB波形比较规整的大振幅非线性驻波,并在三阶、五阶共振频率激励下观察到了谐波饱和现象和锯齿波.A standing-wave tube consisting of two tubes with abrupt changing diameters is dissonant,that is,its higher resonance frequencies are not integral multiples of the fundamental one. Using the dissonant property of the said standing-wave tube,the harmonics can be well suppressed and extremely pure nonlinear standing wave can be obtained at the first resonance frequency. Based on the study of the dissonant property of this standing-wave tube and by the straight connection of a high-power loudspeaker,184 dB extremely pure nonlinear standing-wave field was obtained at the first resonance frequency. Moreover,the nonlinear standing-wave fields were experimentally investigated separately for the second resonance frequency up to the fifth. Relatively regular nonlinear standing-wave field of 180 dB was obtained at the third resonance frequency,and that of 166 dB was obtained at the fourth resonance frequency. The harmonics saturation phenomena and zigzag waveforms were observed at the third and the fifth resonance frequency,respectively.

关 键 词：失谐驻波管 大振幅驻波 畸变 饱和 

分 类 号：O422.2[理学—声学]