Study On Synchronization Of High Frequency Thermoacoustic Oscillators

Among those thermoacoustic energy convertors, high frequency thermoacousticoscillators were characterized as devices of small dimensions and high power output,while they can exploit low grade heat source better. However, the heat flux and acousticpower were limited by their dimensions, thus it’s difficult to meet the need of engineeringfor single oscillator. Arrays consisting of multiple thermoacoustic oscillators effectivelyincreased energy flux while preserving advantages of single oscillator. As an example ofself-sustained oscillators, coupling between thermoacoustic oscillators has a greatinfluence on the power output of array devices. Basis on the theory of synchronization,theoretical and experimental research on oscillators containing cavity were conducted interms of synchronization.Dynamic approach of synchronization between two self-sustained oscillators withsmall amplitude oscillation was described, averaged equations of phase and amplitudeunder the conditions of weakly coupling and weakly nonlinear oscillations respectively.Then an array device consisting of two thermoacoustic oscillators, operating near5kHz,was designed and simulated with regard to frequency, phase and amplitude usingTANetwork software. Experimental research on an array of oscillator driven by PZT wascarried out, demonstrating the relationship between phase difference and amplitude. Fromthe results of cavity experiment and acoustic coupling, experimental scheme about arrayof thermoacoustic oscillator was put forward.As a result, sound pressure of array devices was influenced by the character of cavity.The numerical simulation of two array thermoacoustic oscillator revealed the distributionof phase and sound pressure, contributing to energy utilization of thermoacoustic energyconvertor. Superposition principle of small amplitude oscillation was demonstrated fromthe experiment of sound coupling for two oscillators. The results and conclusions presented can be extended to arrays with larger number of oscillators.