On the viability of the complex-intensity-based near-field acoustical holography method

Because of the instrumentation difficulties of Fourier acoustical holography, it is desirable to find a holography method that does not require reference signals during array scanning. Among the methods that have been investigated to remove the need for references are those based on acoustic intensity measurements, including the complex-intensity-based near-field acoustical holography (CIBNAH) method [A. Nejade, J. Sound Vib. 333(16), 3598–3608 (2014); Appl. Acoust. 116, 348–356 (2017)]. The CIBNAH method has previously been applied to simple contrived sources and real-world machinery but has not been verified using analytical source models. This work shows the application of CIBNAH to an analytical model of a simply-supported plate, revealing key shortcomings of the method. The theory behind CIBNAH is discussed in light of these shortcomings. It is shown that while CIBNAH may be useful for finding radiation hot spots, it is not an adequate method to overcome the need for references in scan-based acoustical holography. [Work supported by NSF.] Because of the instrumentation difficulties of Fourier acoustical holography, it is desirable to find a holography method that does not require reference signals during array scanning. Among the methods that have been investigated to remove the need for references are those based on acoustic intensity measurements, including the complex-intensity-based near-field acoustical holography (CIBNAH) method [A. Nejade, J. Sound Vib. 333(16), 3598–3608 (2014); Appl. Acoust. 116, 348–356 (2017)]. The CIBNAH method has previously been applied to simple contrived sources and real-world machinery but has not been verified using analytical source models. This work shows the application of CIBNAH to an analytical model of a simply-supported plate, revealing key shortcomings of the method. The theory behind CIBNAH is discussed in light of these shortcomings. It is shown that while CIBNAH may be useful for finding radiation hot spots, it is not an adequate method to overcome the need for references in scan-based acoustic...