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 with a term proportional to Re_h^−1/2 in addition to the Darcy-Forchheimer two-term correlation will fit best to the data. This Re_h^−1/2 term accounts for the boundary layer effect at intermediate Reynolds number. The results also show that the correlation for oscillating flows coincides with that for steady flows in 1 < 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.