Bubble formation and rising dynamics analises

Abstract

The main purpose of this dissertation is to contribute to improve the knowledge of the bubble dynamics behavior and to develop appropriate tools to allow the study and description of the bubble formation phenomenon and its subsequent ascending motion under different situations . In this sense , the study has been focused on the generation of bubbles under intermediate injection conditions , i.e. conditions where neither the gas flow rate nor the feeding pressure remain constant during the bubble formation process. Additionally, the bubble ascension motion has been analyzed numerically, characterizing the bubble shape, path and wake as functions of the fluids properties and bubble size. Thus, the neutral curve that defines the transition from a stable to an unstable ascending motion has been established by means of Linear Stability Analysis and Direct Numerical Simulations