Analysis of source models for two-dimensional acoustic systems using the transfer matrix method

The point sound source model calculating the transfer matrix of thin acoustic cavities has been extensively utilized in analyzing certain mufflers. However, the computational result of the transfer matrix is not valid due to the singularity of the point source model. In this paper, a surface source model for thin acoustic cavities is discussed for its convergence characteristic and pressure responses on the source surface, which shows that the pressure responses on the surface are not uniform and the computational results of the transfer matrix coefficient are questionable. Finally, the circular line sound source model is suggested. Through theoretical analysis and computational examples, it is shown that this model avoids the singularity of source and obtains the uniform pressure responses on the circular line. Compared to the circular surface source, it is more convenient and has approximate averaged pressure responses if the circular radius is reasonably selected.