Measurement of the air bubble size and velocity from micro air bubble generation (MBG) in diesel using optical methods

Abstract

In this paper, we determine the bubble size and velocity from air bubble generation (MBG) in a diesel using optical methods. A KTM Series Pump was used to generate micro air bubbles in diesel. The air bubble radius and velocity measurements can be useful parameters to optimize the bubble generation process. Two optical systems were used for measurement air bubble sizes and their velocities in diesel. First, the optical system without an objective lens was used to determine the velocity of air bubbles in diesel. Another optical system with a 10× objective lens was used to obtain the size distribution of air bubbles generated in diesel. An available optical system with a 10× objective lens can detect a bubble diameter greater than 3.3 µm that air bubble images were processed using the ImageJ program. We measured the size distribution of air bubbles generated using the ImageJ program. The micro air bubble radius measured in diesel was found to be 6.26 µm in the sample after a month from air bubble generation. In addition, the particle image velocimetry (PIV) technique was used to measure the velocity field. Then, we used the OpenPIV program for PIV image processing. The highest velocity distribution was determined to be 90 mm/s for diesel without air bubbles and 20 mm/s for diesel with air bubbles after a month of the bubble generation.

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

“…An airflow rate of 0.6 Lpm produces bubbles of 150 -500 μm [32] and 200 -400 [42]. With direct air, Alfarraj et al [22], using Matlab, can produce bubble diameters ranging from 6.26 -10 μm. Swart et al [33], with an airflow rate of 1.5 Lpm, can produce bubble diameters ranging from 88 -102 μm.…”

“…In the experimental study of microbubble generators, accurate bubble characterization is essential. Bubble size measurement is an important parameter to know MBG [22]. The size of air bubbles has been measured in many studies [23].…”

Optical Multi-Parameter Measuring System for Fluid and Air Bubble Recognition

“…In 2020, Alfarraj et al measured the air bubble size and velocity in diesel using an optical method [ 18 ]. They used a 532 nm double-pulse laser (based on Nd:YAG) with cylindrical lenses to expand the 2-D sheet beam impinging on a cuvette and a CCD camera to acquire pictures.…”

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

“…One alternative application is high-performance aerators with microbubble technology. This technology is better known as microbubble generators (MBG or MBGs) (Afisnaa et al, 2017;Alfarraj et al, 2020;Basso et al, 2018;Juwana et al, 2019;Liew et al, 2020). 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).…”