hydrodynamic study of a rising bubble in the presence of cetyltrimethylammonium bromide surfactant

The performance of surfactants especially in two-phase systems, depends on their type, hydrophile-lipophile balance (hlb) number, concentration, and whether the surfactant is ionic or non-ionic. the current work was conducted to study the effect of the presence of cetyltrimethylammonium bromide (ctab), a cationic surfactant, in air-water systems. thus, the behavior of a single air bubble rising in aqueous ctab solutions was studied experimentally. the independent test variables are solution concentration (0.4-1.6mm) and bubble diameter (3.5-4.6mm). the effect of these variables on rising velocity, bubble shape, and drag coefficient has been studied. due to the importance of the drag coefficient in two-phase fluid, the effect of reynolds number, eötvös number, and aspect ratio on it has also been evaluated. experiments have been performed at high reynolds numbers (850