Microbubble generators are of considerable importance to a range of scientific fields from use in aquaculture and engineering to medical applications. This is due to the fact the amount of sea life in the water is proportional to the amount of oxygen in it. In this paper, experimental measurements and computational Fluid Dynamics (CFD) simulation are performed for three water flow rates and three with three different air flow rates. The experimental data presented in the paper are used to validate the CFD model. Then, the CFD model is used to study the effect of diverging angle and throat length/throat diameter ratio on the size of the microbubble produced by the Venturi-type microbubble generator. The experimental results showed that increasing water flow rate and reducing the air flow rate produces smaller microbubbles. The prediction from the CFD results indicated that throat length/throat diameter ratio and diffuser divergent angle have a small effect on bubble diameter distribution and average bubble diameter for the range of the throat water velocities used in this study.

The critical design parameter when sizing a separator is the size of oil droplets in the water phase. This study improves the design of a separator by investigating the parameters that control droplet size, frequency, and distribution.

Accurate visualization of bubbles in multiphase flow is a crucial aspect of modeling heat transfer, mixing, and turbulence processes. It has many applications, including chemical processes, wastewater treatment, and aquaculture. A new software, Flow_Vis, based on experimental data visualization, has been developed to visualize the movement and size distribution of bubbles within multiphase flow. Images and videos recorded from an experimental rig designed to generate microbubbles were analyzed using the new software. The bubbles in the fluid were examined and found to move with different velocities due to their varying sizes. The software was used to measure bubble size distributions, and the obtained results were compared with experimental measurements, showing reasonable accuracy. The velocity measurements were also compared with literature values and found to be equally accurate.

This paper investigates the effect of liquid flow and oil pad thickness on the droplet size and separation performance. The findings show that increasing the inlet flow rates of the oil and water results in size reduction of the droplets. Increasing the thickness of the oil pad increases the size of the droplets. The measured data were fitted with a simple Gaussian model, and the fitted parameters of mean, standard deviation and amplitude were determined for each data set. Trends have been obtained from the fitted parameters as a function of the Reynolds number. The key parameter to predict and fix the position of the Gaussian distribution was found to be the mean droplet size. Simple Ab initio calculation methods to estimate this parameter was tested against the experimental data to identify the most promising method to predict this parameter for modelling purposes.