Experimental study on single bubble dynamics in liquids with varying viscosities: detachment behavior and predictive model modification

• Bubble dynamics were studied across a wide range of liquid viscosities. • High-speed imaging quantified the bubble formation, growth and deformation. • Higher viscosity delayed detachment and stabilized bubble shape and motion. • A new correlation improves detachment size prediction with an 11% deviation. Bubble dynamics in viscous fluids are critical for the design of gas–liquid reactors. The complete lifecycle of single bubbles in deionized water, propylene glycol, and glycerol is investigated using high-speed photography and image processing. Detachment diameter, aspect ratio, and instantaneous velocity are quantified across a wide viscosity range under controlled negative pressure. Results indicate that higher liquid viscosity increases viscous drag, which significantly prolongs the growth and necking stages, leading to larger detachment volumes. As viscosity increases, bubble trajectories transition from unstable zigzag paths to stable vertical ascents, while shape oscillations and deformations are suppressed. The instantaneous velocity decreases, and the acceleration phase lengthens as the liquid viscosity increases. A new predictive correlation for detachment diameter is developed by incorporating the Morton number ( Mo ) to account for the combined effects of viscosity and surface tension. The model demonstrates high accuracy, with average absolute deviations of 6.43%, 8.56%, and 10.24% for the tested liquids. This correlation enables the calculation of gas–liquid interfacial area and bubble residence time, serving as a practical tool for process intensification in high-viscosity chemical systems.