HEAT TRANSFER AND FLOW-FRICTION CHARACTERISTICS IN PERIODICALLY REVERSING FLOW FOR THERMAL REGENERATORS
A thermal regenerator consisting of randomly packed metal spheres of uniform diamter was tested in periodically reversing flows using air as the working gas. The flow cycling rate was varied from 5.6 to 27 reversals per second, and the rate of pressure fluctuation was varied from 180 to 1,200 psi per second. The enthalpy flux method was used to determine the heat transfer in the regenerator, and a mathematical model, based on assumptions of sinusoidally varying mass flow rate and pressure, was used to obtain correlations for the heat transfer and flow-friction coefficients. Temperature dependent fluid properties were used in the analysis. The results were compar.ed to those of other investigators.