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

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.

Design and fabrication of a vigorous “cavitation-on-a-chip” device with a multiple microchannel configuration

“…However, applications of HC at the conventional scale have been successfully realized in the food and beverage industry [4][5][6] and hydrometallurgy 7 . Furthermore, its extensive applications at the microscale are emerging, such as wastewater treatment 8 , biomedical applications [9][10][11] , energy harvesting 12,13 , and liquid phase exfoliation 14 .…”

“…The inlet chamber is designed as a rather long section to let the transient chaotic flow disappear before the fluid enters the nozzle area. Based on our previous studies 13,23,26 on microfluidic devices with a single micro-orifice, the inlet chamber was kept 2000 μm wide for each nozzle. Hence, in the present microfluidic device, a 2000 μm wide area is considered for each nozzle in the inlet chamber.…”

Influence of Fluid Properties on Intensity of Hydrodynamic Cavitation and Deactivation of Salmonella typhimurium

“…The volume flow rate of the system (as measured for each data point and the velocity of the working fluid inside the microfluidic device by dividing a reference volume of the exiting fluid by the elapsed time for this volume to leave the system) was utilized for Reynolds and cavitation numbers calculation. Figure 3 shows the schematic of the experimental setup, which was constructed in similar lines with our previous studies (with minor changes such as the removal of the filter) [18]. The PBS/bacteria suspension was collected in sterile biological sample containers upon exiting the microfluidic device and was restored for the next cycle of cavitating flow.…”

Local Carpet Bombardment of Immobilized Cancer Cells With Hydrodynamic Cavitation

“…Depending on the system geometry and working principle, it generates a high amount of energy upon the collapse of emerging bubbles [2]. Due to a wide variety of potential cavitation applications, many researchers have conducted studies on the cavitation physics to facilitate earlier inception [3], [4] and to intensify cavitating flows [5]. The energy released from the collapse of cavitation bubbles has been effectively employed for various applications such as wastewater treatment [6], food manufacturing [7], energy harvesting [8], [9], bacterial inactivation [10], biomedical treatment [11], and other industrial applications [12].…”