Influence of the Nonlinearity of Loudspeakers on the Performance of Thermoacoustic Refrigerators Driven by Current and Voltage

The influence of the nonlinearity of electrodynamic loudspeakers on the performance of thermoacoustic refrigerators with the loudspeakers as acoustic sources is studied by nonlinear equivalent circuit models of electrodynamic loudspeakers driven by current and voltage. The simulated results demonstrate that there are different nonlinear effects between current-drive and voltage-drive refrigerators, and the differences are mainly induced by the motional electromotive force caused by the coil moving in the magnetic field. With voltage driving, the influence of the nonlinearity of the loudspeaker on the diaphragm displacement and acoustic output power is much smaller than that with current driving. Therefore, considering the nonlinearity of the loudspeakers, a proper driving method must be chosen according to the practical applications although little difference is found with the linear models.