Experimental Investigation Into Combined Fluctuating Airflow and Mist Evaporative Cooling

This study investigates the potential of fluctuating flows to enhance mist evaporation — a dimension that has not been systematically investigated in prior research. Controlled wind tunnel experiments were conducted to explore the influence of fluctuating airflow in comparison to constant airflow on misting processes. The outcomes unveiled that mist-cooled flows subjected to fluctuating airflow exhibited lower temperatures and higher humidity values compared to those under constant airflow at a steady state. At an average velocity of 2 m/s, the humidity ratio of the flow rose from 8.4 g/Kg to 8.9 g/Kg under constant airflow, and further increased to 9.1 g/Kg with fluctuating airflow. Similarly, at an average velocity of 3 m/s, the humidity ratio increased from 8.3 g/Kg without misting to 9.3 g/Kg and 9.8 g/Kg for constant and fluctuating airflows, respectively. These findings strongly suggest an increase in the total evaporation rate of misted water. Potential factors contributing to this enhancement may encompass increased flow instability, augmented turbulence, and enhanced mixing. The dataset generated through this study can serve as a validation resource for computational fluid dynamics models, which are essential for analyzing the intermediate factors responsible for the observed enhancements and performing parametric assessments.