A Review on Acoustic Reconstruction of Temperature Profiles: From Time Measurement to Reconstruction Algorithm

Acoustic tomography is a technique widely used in nonintrusive temperature measurement. The time of flight (TOF) of acoustic waves can be used to estimate the temperatures of a measurement area. After obtaining the TOF of some transmitter-receiver pairs, the temperature profile of the probed area can be estimated by some reconstruction algorithms. Temperature profiles play a critical role in the safe operation and efficient control of thermal-related mechanical systems. This article aims to present a systematic review of the acoustic reconstruction of the temperature profile, including TOF measurements and reconstruction algorithms. First, time-domain, Fourier-domain, and hybrid-domain methods for the TOF measurement are revisited and discussed. Second, algorithms for the solution of the reconstruction model are reviewed from three groups of regularization methods. We also discuss how to choose the regularization parameter and form a good preconditioner for fast calculation. Third, some extensions in TOF measurements and reconstruction methods and potential errors that may affect acoustic reconstruction are also discussed. Finally, some applications are presented. A framework for the whole reconstruction process can be a useful resource to help researchers select a proper method for specific applications.