Experimental study on the heat transfer at the heat exchanger of the thermoacoustic refrigerating system

Oscillatory flow heat transfer at the heat exchanger of the thermoacoustic refrigeration system was studied. The study identified significant factors that influence this heat transfer as well as the construction of the system. The results from the experimental study were correlated in terms of Nusselt number, Prandtl number and Reynolds number to obtain a useful new correlation for the heat transfer at the heat exchangers. Results show that using straight flow heat transfer correlations for analyses and design of this system could result in significant errors. Results also show the relationship between the oscillatory heat transfer coefficient at the heat exchangers, the mean pressure and frequency of oscillation. Higher mean pressures result in greater heat transfer coefficients if the thermoacoustic refrigerating system operates at the corresponding resonant frequency. However, a compromise has to be reached to accommodate construction of the stack.