Single bubble motion in two and three phase systems
Sprache des Vortragstitels:
(Bio)Process Engineering ? a Key to Sustainable Development
Sprache des Tagungstitel:
Accurate scale-up of two and three-phase reactors hinges on the accurate prediction of gas hold-up because heat and mass transfer are strongly dependent on the fluid dynamics and they are quantifying via equations in which gas hold-up plays a vital role. Accordingly, numerical simulations must be performed to investigate the behavior of the gas phase. In this work, we investigated CO2 and air bubbles in two Newtonian (water and kerosene) and a non-Newtonian (aqueous solutions of Carboxymethyl cellulose (CMC)) liquids numerically and experimentally to understand the effects of gas type and liquid type on the behavior of each size of bubbles.
The results indicate that the CO2 and air bubbles showed nearly identical trajectories and velocity at small bubble sizes there the form drag is insignificant. By increasing the bubble size, the differences between the velocity of them become more significant so that the differences between the velocity of large CO2 and air bubbles (d ? 6 mm) become clearly visible there the form drag plays a major role and brings about a noticeable change in drag coefficient. The trajectories instead are still identical.