Engineered Lateral Roughness Element Implementation and Working Fluid Alteration to Intensify Hydrodynamic Cavitating Flows on a Chip for Energy Harvesting.

Morteza Ghorbani,Moein Talebian Gevari,Luis Guillermo Villanueva,Ali Koşar,Ali Hosseinpour Shafaghi

doi:10.3390/mi11010049

Abstract

Hydrodynamic cavitation is considered an effective tool to be used in different applications, such as surface cleaning, ones in the food industry, energy harvesting, water treatment, biomedical applications, and heat transfer enhancement. Thus, both characterization and intensification of cavitation phenomenon are of great importance. This study involves design and optimization of cavitation on chip devices by utilizing wall roughness elements and working fluid alteration. Seven different microfluidic devices were fabricated and tested. In order to harvest more energy from cavitating flows, different roughness elements were used to decrease the inlet pressure (input to the system), at which cavitation inception occurs. The implemented wall roughness elements were engineered structures in the shape of equilateral triangles embedded in the design of the microfluidic devices. The cavitation phenomena were also studied using ethanol as the working fluid, so that the fluid behavior differences in the tested cavitation on chip devices were explained and compared. The employment of the wall roughness elements was an effective approach to optimize the performances of the devices. The experimental results exhibited entirely different flow patterns for ethanol compared to water, which suggests the dominant effect of the surface tension on hydrodynamic cavitation in microfluidic channels.

Highlights

Cavitation has received more and more attention during the last decade due to the potential for its implementation in many applications, such as biomedical ones [1], energy harvesting [2], surface cleaning, and water treatment [3,4,5]
The optimization process was performed in three phases, which are explained
The initially designed microfluidic device was equipped with six different lateral wall roughness element configurations, and the performances of the configurations were studied experimentally

Summary

Introduction

Cavitation has received more and more attention during the last decade due to the potential for its implementation in many applications, such as biomedical ones [1], energy harvesting [2], surface cleaning, and water treatment [3,4,5]. Cavitation is associated with a process involving the nucleation, growth, and implosion of bubbles filled with vapor or gas. Such cavities are generated in a fluid when the static pressure drops below the vapor saturation pressure of the fluid. These bubbles implode violently when encountering a higher pressure region, resulting in high temperature spots. Hydrodynamic cavitation is known to be more energy efficient because of rather simple configuration and construction of related systems, low energy requirements, and easier scaling up possibility for industrial applications [8,9,10]

Methods

Results

Conclusion