An Experimental Study on Wind-Driven Runback Characteristics and Dynamic Icing Process of Water Droplet/Rivulet Flows over a Frozen Cold Surface

An experiment investigation is conducted to examine the transient runback characteristics and dynamic ice accretion process of water droplets as driven by frozen-cold boundary layer airflows over a flat plate under the controlled ambient temperatures of T_∞ = −5 °C, −10 °C, and −15 °C, respectively. During the experimental campaign, while a novel Digital Image Projection (DIP) technique was used to quantify the dynamic shape changes of the freezing water droplet/rivulet flows, a digital Particle Image Velocimetry (PIV) was used to characterize the development of the boundary layer airflows over the wind-drone runback water droplets/rivulets. A high-speed infrared (IR) thermal imaging system was also synchronized with the DIP and PIV systems to reveal the time evolution of the temperature distributions of the freezing water droplets/rivulets for a better understanding of the unsteady heat transfer characteristics associated with the solidification process of the freezing water droplets/rivulets. A better understanding of the characteristics of wind-driven water droplet/rivulet flows and the dynamic solidification process of the freezing water droplet/rivulet flows over solid surfaces is crucial to elucidating the underlying physics of the atmospheric icing phenomena, which can lead to the development of more efficient and robust icing protection systems to ensure safer and more efficient operation of aircraft, Unmanned-aerial-system (UAS) and wind turbine operation in cold climates.