Investigation on the pressure drop characteristics of cryocooler regenerators under oscillating flow and pulsating pressure conditions Original Research Article

This paper proposes a new oscillating flow model of the pressure drop in oscillating flow through regenerator under pulsating pressure. In this oscillating flow model, pressure drop is represented by the amplitude and the phase angle with respect to the inlet mass flow rate. In order to generalize the oscillating flow model, some non-dimensional parameters, which consist of Reynolds number, Valensi number, gas domain length ratio, oscillating flow friction factor and phase angle of pressure drop, are derived from a capillary tube model of the regenerator. Two correlations in the model are obtained from the experiments for the twill square screen regenerators under various operating frequencies and inlet mass flow rates. It is found that the oscillating flow friction factor is a function of Reynolds number while the phase angle of pressure drop is a function of Valensi number and the gas domain length ratio. Experiment also shows the effect of the mesh weave style on the oscillating flow friction factor and the phase angle. Proposed oscillating flow model can accurately describe the amplitude and the phase angle of the pressure drop through the regenerator.