引入声汇的相位共轭方法进行声场识别

在时间反转方法中引入声汇概念的基础上，提出两种方法计算引入的声汇幅值：第一种方法是直接推导出相位共轭阵列在声源聚焦处的幅值，将其作为声汇的幅值；第二种方法是在近场引入一个测量球面计算声汇的幅值，并讨论引入测量球面半径对声场重建结果的影响。数值计算结果表明：引入声汇之后，在一定的测量距离上，采用两种计算方法都能突破声波的衍射极限；通过引入的测量球面方法，采用封闭的球形阵列在远场也能突破声波的衍射极限，得到结果更精确，与点声源理论解吻合较好；根据倏逝波传播性质，引入的测量球面半径需小于一个波长。

Sound Identification using Phase Conjugation by Introducing the Acoustic Sink

Two methods for calculating the amplitude of the acoustic sink, by introducing the concept of the sink in time reversal method, are proposed. The first method is to derive the amplitude of the phase conjugation array in the focusing location of the acoustic sources directly, which is employed as the amplitude of the acoustic sink. The second method is to calculate the amplitude of the acoustic sink by introducing the measurement spherical surface. The effect of the spherical radius on focusing properties is also discussed. The numerical results show that the diffraction limit can be broken through at a certain distance by introducing the acoustic sink for the two methods. The best reconstruction can be obtained by considering the spherical measurement surface, that can yield more accurate results which agree well with the theoretical solution of the point source. The radius of the spherical measurement surface must be less than the wavelength according to the properties of the evanescent waves.