On pressure-velocity correlation of steady and oscillating flows in regenerators made of wire screens

A facility capable of generating steady and oscillating flows was constructed and experiments were conducted to investigate the pressure-drop characteristics of regenerators packed with wire screens. Both the velocity and pressure-drop across the regenerator were measured. To accurately determine the correlation between pressure-drop and velocity, the experiments covered a wide range from very low to very high Reynolds numbers, Re-h. The steady flow results reveal that a three-term correlation correlation will fit best to the data. This Re-h(-1/2) term accounts for the boundary correlation with a term proportional to Re-h(-1/2) in addition to the Darcy-Forchheimer two-layer effect at intermediate Reynolds number: The results also show that the correlation for oscillating flows coincides,with that for steady flows in I < Re-h < 2000. This suggests that the oscillating flows in the regenerators behave as quasi-steady at the frequency range of less than 4.0 Hz, which is the maximum operable oscillating flow frequency of the facility.