The effect of roll-cells on mass transfer

✍ Scribed by E. Ruckenstein; C. Berbente

• Publisher: Elsevier Science
• Year: 1970
• Tongue: English
• Weight: 561 KB
• Volume: 25
• Category: Article
• ISSN: 0009-2509
• DOI: 10.1016/0009-2509(70)80045-8

✦ Synopsis

The hydrodynamic structures generated by turbulence (interfacial or bulk) is represented by means of roll-cells propagating in the main direction of motion with the average velocity of the liquid. An analytical expression is proposed for these structures and on its basis the unsteady convective diffusion equation is solved. The amplification of the mass flux with respect to that given by the penetration theory is obtained as a function of a single dimensionless quantity Q,, = Akuo/Dk12. For small values of (Ye the mass flux can be obtained from that resulting from the penetration theory by replacing the molecular diffusion coefficient by an apparent constant larger one. For large values of (Y~ arguments are adduced that the mass flux can be calculated from an equation similar to the one obtained on the basis of the renewal models.