Energy Conversion from Sound to Heat Using Lamination Mesh on the Thermoacoustic System

Abstract

Experimental investigations have been carried out to improve the energy conversion efficiency of the loop tube: a thermoacoustic cooling system. Generally, increasing the proportion of thermal boundary layers in a stack improves the energy conversion efficiency of a thermoacoustic cooling system. Decreasing the channel radius of the stack is necessary to increase the proportion of the thermal boundary layer in the cross section of the stack. It is difficult for a ceramic stack to reduce the channel radius of the stack because of the present manufacturing techniques. Thus, we use a lamination mesh formed by piled up stainless mesh to do so. Nevertheless, the lamination mesh cooling property is unclear, as it is related to ωτ, which is a parameter for determining heat exchange. In this expression, ω is the angular frequency of the sound wave and τ is the time required for thermal equilibrium in the cross section of the stack channel. Using the acoustic tube, experiments were carried out by changing the mesh number of the lamination mesh and the insertion position to assess the cooling characteristics of the lamination mesh. Experimental results reveal a tendency resembling that shown by a ceramic stack. Moreover, the ωτ and channel radius of the lamination mesh were estimated using the result in our previous work. Results show that this design method can be adapted to the use of the lamination mesh and ceramic stack.