Document Type
Article (Restricted)
Publication Date
5-1-2015
Abstract
This paper aims at investigating the influence of ultrasound power amplitude on liquid behaviour in a low-frequency (24 kHz) sono-reactor. Three types of analysis were employed: (i) mechanical analysis of micro-bubbles formation and their activities/characteristics using mathematical modelling. (ii) Numerical analysis of acoustic streaming, fluid flow pattern, volume fraction of micro-bubbles and turbulence using 3D CFD simulation. (iii) Practical analysis of fluid flow pattern and acoustic streaming under ultrasound irradiation using Particle Image Velocimetry (Ply). In mathematical modelling, a lone micro bubble generated under power ultrasound irradiation was mechanistically analysed. Its characteristics were illustrated as a function of bubble radius, internal temperature and pressure (hot spot conditions) and oscillation (pulsation) velocity. The results showed that ultrasound power significantly affected the conditions of hotspots and bubbles oscillation velocity. From the CFD results, it was observed that the total volume of the micro-bubbles increased by about 4.95 with each 100 W-increase in power amplitude. Furthermore, velocity of acoustic streaming increased from 29 to 119 cm/s as power increased, which was in good agreement with the PIV analysis. (C) 2014 Elsevier B.V. All rights reserved.
Keywords
Ultrasound, Micro bubbles, Acoustic streaming, Computational Fluid Dynamics (CFD), Particle Image Velocimetry (PIV)
Divisions
fac_eng
Funders
University of Malaya High Impact Research Grant from the Ministry of Higher Education Malaysia HIR-MOHE-D000038-16001 ,University of Malaya Bright Spark Unit
Publication Title
Ultrasonics Sonochemistry
Volume
24
Publisher
Elsevier
Additional Information
Sajjadi, Baharak Raman, Abdul Aziz Abdul Ibrahim, Shaliza eng Research Support, Non-U.S. Gov't Netherlands 2014/12/02 06:00 Ultrason Sonochem. 2015 May;24:193-203. doi: 10.1016/j.ultsonch.2014.11.013. Epub 2014 Nov 18.