The interfacial dynamics of the micrometric droplet diameters during the impacting onto inclined hot surfaces

The interfacial dynamics of the micrometric size liquid droplets during impact onto inclined hot surfaces have been experimentally studied. The inclination angles were varied at 15° 30° and 45° from horizontal for surface temperatures were decreasing from 500 °C to 100 °C. The droplet diameters tested were 500 μm and 700 μm. The tested material was stainless steel-grade 304 (SUS 304) with varying surface roughness ranging from Ra 0.04 up to Ra 10. The interfacial dynamics during the impact onto inclined hot surfaces were investigated by using a high-speed video camera with the frame speed of 15,000 fps. The objectives of this study are to provide insight into the dynamic behaviors of contact angles and dependence of importance parameters at various surface temperatures. It was found that depending on the surface temperature the droplet evaporation and its bouncing process play an important role on the droplet detachment mechanisms from the inclined surface. Three transient regions of the interfacial evolution during the micrometric droplets impacting onto oblique hot surface were identified. Moreover, the contribution of the important physical parameters, such as, advancing and receding contact angles on the interfacial dynamics are presented.