A Summary: Dynamic and thermodynamic analysis of thermoacoustic and Stirling systems based on time-domain acoustic-electrical analogy

Abstract

A unified fast transient simulation method for thermoacoustic and Stirling systems has been developed, named time-domain acoustic-electrical analogy (TDAEA) method. From a thermoacoustic theory point of view, the method captures the main acoustic impedance characteristics of the components and simplifies the calculations reasonably by using lumped models for components, thus remarkably reducing the computation. The TDAEA models of common components in thermoacoustic and Stirling systems are summarised with detail derivation. Two case studies are then carried out on free-piston Stirling generator (FPSG) and heat-driven thermoacoustic refrigerator (HDTR). Model verifications demonstrate the effectiveness and accuracy of the method: for the FPSG, the average deviation between the calculations and experiments in operating frequency, electric power, LA efficiency and thermal-to-electric efficiency are 5.0%, 16.3%, 2.4% and 26.9%, respectively; as for the HDTR, the deviation in cooling power lies in 29.9%. Using this method, transient evolutions can be obtained, which contains both start-up and steady stages. For start-up analysis, the transient operating frequency, pressure–volume diagram and limit cycle, etc, can be exhibited. Regarding the steady stage, the method is available to give the distribution of acoustic field and the losses in components. Moreover, the infulences of operating and geometric parameters on system performance can aslo be obtained. This study provides a new perspective and an effective method for fast transient simulation of thermoacoustic and Stirling systems, as well as gives a deeper understanding on the transient evolution of self-sustained oscillation and dynamic & thermodynamic cycles in these systems.