A review on bubble generation and transportation in Venturi-type bubble generators

Abstract

Venturi-type bubble generators own advantages of simplicity in structure, high efficiency, low power consumption, and high reliability, exhibiting a broad application potential in various fields. This work presents a literature review of recent progress in the research concerning Venturi-type bubble generators, with a focus on the performance evaluation, bubble transportation, and breakup mechanisms. Experimental studies employing flow visualization techniques have played an important role in exploring the bubble transportation and breakup phenomena, which is vitally necessary for clarifying the bubble breakup mechanisms and understanding the working principle and performance of a Venturi channel as a bubble generator. A summarization was carried out on both experimental and theoretical work concerning parameters influencing the bubble breakup and the performance of Venturi-type bubble generators. Based on the geometric parameter optimization combined with appropriate flow conditions, it is expected that Venturi-type bubble generators can produce bubbles with controllable size and concentration to satisfy the application requirements, while a further work is required to illustrate the interaction between the liquid and gas bubbles.

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

“…Their main conclusion is that throat length/throat diameter ratio and diverging angle play key roles in determination of the performance of a Venturi-type bubble generator. For the l/d ratio, the results from Reichmann et al [9] and Huang et al [10] showed that bubble diameter reduced with higher l/d ratio while the results from Unyaphan et al [18] did not support this conclusion. For the diverging angle, Lee et al [19] and compared the bubble diameter produced from five Venturi tubes with different diverging angles in the range of 15 • -45 • .…”

“…Their main conclusion is that throat length/throat diameter ratio and diverging angle play key roles in determination of the performance of a Venturi-type bubble generator. For the l/d ratio, the results from Reichmann et al [9] and Huang et al [10] showed that bubble diameter reduced with higher l/d ratio while the results from Unyaphan et al [18] did not support…”

“…The bubble diameter distribution and the average diameter produced by Venturi are a function of a number of geometric parameters. Huang et al [10] indicated that the parameters include the convergent angle (α), diffuser divergent angle (β), throat length (l), throat diameter (d), outlet diameter (D), and gas feeding hole diameter (d g ). Their main conclusion is that throat length/throat diameter ratio and diverging angle play key roles in determination of the performance of a Venturi-type bubble generator.…”

“…In recent years, a range of different designs of microbubble generators have been used to produce smaller microbubbles, the researchers studying the effect of converging angle, throat length, throat diameter, and diverging angle to understand the geometrical effect on bubble diameters. Their results indicated that further research is required to understand the effect of changing the throat length/throat diameter ratios and the effect this has on the bubble sizing [9][10][11]. Hence, the purpose of this paper is twofold.…”

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

“…Air bubble generation technology has been used to improve vehicle efficiency by reducing fuel consumption and reducing the fuel-air ratio [1]. Many studies were focused on the size distribution of air bubbles measurements to control air-fuel mixing by applying the liquid and airflow rates [2]. Bubble transportation and mechanisms of bubble breakup were also studied.…”