Lift Coefficients of Clean Ellipsoidal Bubbles in Linear Shear Flows. (August 2020)

• Record Type: Journal Article
• Authors: Hayashi, Kosuke; Legendre, Dominique; Tomiyama, Akio
• Is Part Of: International journal of multiphase flow. Volume 129(2020)
• Publication Date: 2020-08
• Subjects: lift force -- lift reversal -- negative lift -- shape deformation; Multiphase flow -- Periodicals; Écoulement polyphasique -- Périodiques; Multiphase flow; Periodicals; 620.1064
• DOI: 10.1016/j.ijmultiphaseflow.2020.103350
• Languages: English
• ISSNs: 0301-9322

Abstract

Highlights: Scaling of the reversal of the lift acting on a bubble is presented. Drag and lift forces are connected with vorticity produced at the bubble surface. The bubble aspect ratio and Reynolds number are primal factors in the lift modeling. A lift correlation accounting for Morton number dependence is presented. Abstract: The lift force acting on an ellipsoidal bubble is known to change its sign, depending on the bubble aspect ratio. The lift reversal has often been modeled in terms of the Eötvös number defined by using the bubble major axis to account for the deformation effect on the negative lift component. This paper presents a physically reliable scaling accounting for the two mechanisms in competition related to the two sources of vorticity: the lift controlled by the shear flow and contribution from the interfacial vorticity source. This scaling is used for developing a correlation that makes possible the lift modeling with the reversal.