Numerical simulation of evaporation and heat transfer of droplet impacting on cylindrical outer surface

To further study the rupture of droplet after its impacting and the influence of different parameters on the droplet evaporation and heat transfer, three dimensional numerical simulation is performed by using CLSVOF method and phase transformation model. The effect of wall temperature, contact angle and impact velocity on the evaporation and heat transfer of droplet are considered in the simulation and the results show that the rupture position is related to the impact velocity of the droplet. When the impact velocity is small, the rupture occurs at the center of the droplet. When the impact velocity is large, the rupture position deviates from the center of the droplet. It is also found that vapor vortexes are generated near the three-phase contact line and the rupture, which strengthen the heat transfer between the droplet and the wall, and increase the heat flux density of droplet side as well. In a short time, the wall temperature has little effect on droplet evaporation, but the impact velocity and contact angle have great effect on droplet evaporation. The smaller the contact angle and the greater the impact velocity, the greater the average heat flux density and the greater the droplet evaporation, which is beneficial to heat transfer between the droplet and the wall. © 2018, Editorial Board of Journal of Harbin Institute of Technology. All right reserved.