Update on the evaluation of different correlations for the flow friction factor and heat transfer of Stirling engine regenerators

This paper is intended to update the overview of different correlations for the friction factor and heat transfer of Stirling engine regenerators given by the Oscillating-Flow Regenerator Test Rig data. For that purpose the data was recalculated using the general applicable set of equations for Reynolds number, friction factor, pressure drop, Nusselt number and heat transfer area. Based on these general definitions, the correlations can be shown in one plot for the flow friction factor and one plot for the Nusselt number, giving a good impression of their characteristics and the deviations among them, which are discussed in the body of this paper.