Modified theoretical model for thermoacoustic couples

The theoretical model of thermoacoustic couples is modified to incorporate more realistic physical processes that are acoustic dissipation within the stack, and the heat exchange between the stack and its surroundings, which were not considered in the previous models. The results show good agreement between the present and previous models at high thermal conductivity of the stack. However, at low stack thermal conductivity, the previous models not only significantly overestimate stack temperature difference (ΔTs) but at certain stack positions they predict values of ΔTs greater than the theoretically possible values. The comparison of ΔTs values predicted by the present and previous theoretical models with the experimental results shows a good agreement between the present model and the experiments while, the previous models significantly overpredict ΔTs for the given range of drive ratios. It is shown that the incorporation of realistic physical processes significantly improves the accuracy of the theoretical model for the thermoacoustic couples.