TY - JOUR
T1 - Coupling mechanism of kinetic and thermal impacts of Rayleigh surface acoustic waves on the microdroplet
AU - Mehmood, Mubbashar
AU - Chaudhary, Tariq
AU - Burnside, Stephen B.
AU - Khan, Umar
AU - Fu, Yongqing (Richard)
AU - Chen, Baixin
N1 - Funding information: We acknowledge the financial support from the UK Engineering and Physical Sciences Research Council (EPSRC) grants EP/P018998/1, and Special Interests Group of Acoustofluidics under the EPSRC-funded UK Fluidic Network (EP/N032861/1). The authors are thankful to the University of Northumbria Newcastle upon Tyne, UK for providing the experimental setup for this work. The authors are thankful to Heriot-Watt University, Edinburgh, UK for their support.
PY - 2022/5/1
Y1 - 2022/5/1
N2 - An experimental study has been conducted to investigate the coupling mechanism between thermal and kinetic impacts of surface acoustic waves (SAW) using a water droplet (25 µl) on the zinc oxide (ZnO) thin-film piezoelectric substrate fabricated on an aluminium plate. The temperature is measured by an infrared (IR) thermal camera, and fluid streaming was detected by particles image velocimetry (PIV). The input power ranges from 0.096 W to 3.2 W resulting in a temperature rise and streaming velocity in the droplet up to 55 °C and 24.6 mm/s, respectively. It is found that the thermal impact is insignificant at lower input power (<0.50 W); however, this becomes dominant when the input power is>2.0 W. The study also found that heat inside the droplet is distributed via streaming from the heat source. The heat is distributed from the heat source where SAW power penetrates to the droplet. Another key finding of this investigation revealed that when the input power is>0.50 W, inverse heat transfer from the droplet to the substrate is observed due to the increase in fluid temperatures.
AB - An experimental study has been conducted to investigate the coupling mechanism between thermal and kinetic impacts of surface acoustic waves (SAW) using a water droplet (25 µl) on the zinc oxide (ZnO) thin-film piezoelectric substrate fabricated on an aluminium plate. The temperature is measured by an infrared (IR) thermal camera, and fluid streaming was detected by particles image velocimetry (PIV). The input power ranges from 0.096 W to 3.2 W resulting in a temperature rise and streaming velocity in the droplet up to 55 °C and 24.6 mm/s, respectively. It is found that the thermal impact is insignificant at lower input power (<0.50 W); however, this becomes dominant when the input power is>2.0 W. The study also found that heat inside the droplet is distributed via streaming from the heat source. The heat is distributed from the heat source where SAW power penetrates to the droplet. Another key finding of this investigation revealed that when the input power is>0.50 W, inverse heat transfer from the droplet to the substrate is observed due to the increase in fluid temperatures.
KW - Rayleigh SAW
KW - Radiated heat transfer
KW - Energy absorbed
KW - ZnO thin film
UR - http://www.scopus.com/inward/record.url?scp=85121978991&partnerID=8YFLogxK
U2 - 10.1016/j.expthermflusci.2021.110580
DO - 10.1016/j.expthermflusci.2021.110580
M3 - Article
SN - 0894-1777
VL - 133
SP - 1
EP - 9
JO - Experimental Thermal and Fluid Science
JF - Experimental Thermal and Fluid Science
M1 - 110580
ER -