Experimental and numerical studies of interaction between liquid droplets with hot surfaces under different conditions

Abstract In the present paper, experimental and numerical studies for the interaction studies between different liquid droplets and hot metal surfaces were carried out. The obtained results were interpreted using graphs and figures. Droplet impact, spreading, breakup and Leidenfrost phenomenon were observed with the help of a video camera at 100 fps. The interaction studies were done at different surface temperatures and different droplet‐impinging velocities. Three metals and three liquids were selected for the present study. Copper, aluminium and steel were selected as metals with varying roughness factors maintained at different temperatures. At the same time, in liquid entities, methanol, ethanol and kerosene were selected along with water in some portions. The selections of the metals were based on the thermal diffusivity property as it influences the thermal interaction between the droplet and the hot metal surface. The temperature range of the metal surface was kept from 150°C to 425°C, and the impinging velocity range of droplets was in the field of 2.4–4.9 m/s. For computational studies, the Ansys Fluent R3‐2019 version was used. Numerical analysis for the interaction process was carried out using the volume of fluid (VOF) method, solving Navier–Stokes and energy equations in a 2D‐geometry transient simulation. Parameters like surface temperature, heat flux and spreading ratio w.r.t. change in Weber number were investigated and presented in the present paper. Obtained results are useful for better understanding of droplet physics while interacting with hot surfaces which further helps in development of new methods for effective spray system designs. Results show that for a lower value of Weber number, the droplets spread less as compare to high Weber number. Also, spreading ratio of droplets depends only on the surface roughness.