Geometrical Optimization of a Venturi-Type Microbubble Generator Using CFD Simulation and Experimental Measurements

Abstract

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.

Effect of Lens Aperture for Analysis of Bubble Image Size Microbubble Generator Aeration System

“…Afisna et al [32], with various speeds, the airflow rate ranges from 0.1 -1 Lpm producing bubble diameters ranging from 150 -500 μm. Type Injector with the speed of airflow rate 0.05 -0.2 Lpm produces bubble diameter range 60 -100 µm [18]. Wang et al, [16,48] using Computational Fluid Dynamics (CFD) generates bubbles ranging from 0 -0.2 mm.…”

“…So that it can be used as an alternative aeration system in aquaculture. There are various types of MBGs have been developed, such as; dissolved air flotation (DAF) [8,9], Nozzle venturi [10], Orifice [1,6,11], Venturi [12][13][14][15][16], Injector [17,18] and direct air [8,19]. However, existing MBG systems provide less than maximum results, such as blockage [20] and ineffective [21].…”

Contemporary application of microbubble technology in water treatment

“…Pressurised fluid enters through the inlet and velocity of the fluid increases at the cost of a decrease in static pressure in narrow cross-section throat. This accelerated fluid generates cavitation and sucks in the gas creating microbubbles (Wilson et al 2021). This type offers the benefit of lesser pump power, and compacted size.…”

Effect of Power Pump and Nozzle Diameter Microbubble Generator to Increase Oxygen Concentration in Aquaculture

“…MBG can produce micro-sized bubbles (Deendarlianto et al, 2015;Rizaldi et al, 2019) and accelerate to increase DO concentration (Jeon et al, 2018;Rahmawati et al, 2021), and save energy (Parmar & Majumder, 2013). There are various methods for generating a microbubble technology: Using venturi (Dey et al, 2020;Huang et al, 2021;Wilson et al, 2021;Yadav et al, 2019), using Nozzle (Alam et al, 2018;Ferrando et al, 2021;Khan et al, 2020;Kim & Lee, 2021;Lee et al, 2019;Lin et al, 2018;Wu et al, 2021), using Orifice (Basso et al, 2018;Daskiran et al, 2019;Deendarlianto et al, 2015;Juwana et al, 2019;Kataoka et al, 2020;Liew et al, 2020;Miao et al, 2021;Morito & Makuta, 2018;Rizaldi et al, 2019;Sadatomi et al, 2012), and used DAF Kiuru, 2001). However, various microbubbles have a reasonably small dimension size, and some use compressors or blowers for air distribution.…”