Fundamental Study for the Solution of Thermoacoustic Phenomenon Using Numerical Calculation: Relationship between the Stack Installation Position and Heat Flow

Abstract

Thermoacoustic systems have several advantages owing to their simple structure driven by heat energy such as waste heat and solar heat. However, because their energy conversion efficiency is low, they have not been developed for practical use. Therefore, to improve energy conversion efficiency, a method of system design development is examined in this report using numerical calculations. First, calculation results obtained using the transfer-matrix methods are compared with experimentally obtained results, which confirms their good agreement. Secondly, calculated results of each heat flow element in the stack show that heat flow proportional to the temperature gradient QD, which decreases the performance of the system, is dominant. Finally, the installation position of the stack is changed to reduce the ratio that QD occupies in the heat flow. Results show a decrease in the ratio obtained by moving the stack installation position closer to the center of the tube. Energy conversion efficiency was increased eight times.