A closed loop wind tunnel that allows for high-quality optical observation was designed. Droplets were subjected to shear flow in the wind tunnel and the CCD cameras mounted horizontally and vertically were used to acquire the shape information to experimentally investigate the droplet evaporation. It is found that the droplet will experience three stages under the shear flow and airflow could enhance the evaporation rate significantly. For the droplet of 10 μL, the evaporation rate is 168% higher in 2 m/s wind speed than that without wind. However, increasing the wind speed can not improve the evaporation rate when the wind speed is high. The effect of airflow on the shape of droplet is mainly dependent on the Weber number and the dimensionless number k', which characterizes the ratio of wind force and adhesion force. The effect of shear flow on mass transfer at the gas-liquid interface was investigated, and the relationship between the dimensionless Reynolds number and the Sherwood numbers was determined. It was determined that the theoretical relationship between wind speed and evaporation rate is consistent with experimental data.
LI Zilong
,
QIN Jun
,
TAO Yuequn
,
HE Naifeng
,
LIU Qiusheng
,
ZHU Zhiqiang
. Investigation of pinned evaporation droplets under different wind velocity[J]. Journal of University of Chinese Academy of Sciences, 2025
, 42(3)
: 403
-411
.
DOI: 10.7523/j.ucas.2023.053
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