Influence of hydraulic radius of regenerator on the optimization of phase difference

To reduce the viscous dissipation, the nonzero hydraulic radius of regenerator is adopted in practical thermoacoustic devices, which will lead to deviation of the phase difference between the oscillating temperature and the oscillating pressure because of the thermo-relaxation. For improving the thermoacoustic performance, the nonzero leading phase of oscillating pressure to oscillating velocity is necessary to match the phase deviation due to the thermo-relaxation. Based on the basic thermoacoustic formulas and numerical simulation, the influence of hydraulic radius of the regenerator on the optimization of the phase difference is discussed in this paper. Additionally, our theoretical results also show a good agreement with the experimental data[1], which indicates the validity of the analysis in this paper. Furthermore, the analysis in this paper further provides a more intensive understanding of these experimental results. The conclusions obtained in this paper are significant to guide for the design of new thermoacoustic devices.