The Effect of Voidage on the Drag Force on Particles, Droplets and Bubbles in Dispersed Two-Phase Flow
نویسنده
چکیده
In dispersed two-phase flow, experimental data indicate that the effective drag force on individual dispersed elements∗ is strongly influenced when the dispersed phase is present at high volume fractions. This appears to be true whether the DPEs are solid or fluid (i.e. droplets or bubbles). The paper first reviews the literature relating to the modelling of the drag force in densely dispersed solid-liquid, gas-liquid and liquid-liquid systems. The various models are then compared with an extensive set of data obtained from the literature in order to assess their validity. The paper will show that the various models often give widely different predictions and can even give the wrong trend. In order to improve the prediction capabilities, new correlations to express the influence of the value of phase fraction on the drag force in such systems are formulated. Theses are then validated by comparing their predictions for the slip velocity against available experimental data.
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