Investigation of the dynamic behavior an‎d freezing of supercooled dro‎plets in collision with solid surfaces

1/21/2026 12:00:00 AM

The impact of a supercooled dro‎plet on a surface is a primary challenge of many industrial an‎d aeronautical processes. In the first part of this study, we investigated the effect of surface morphology on the impacting-freezing process of a supercooled dro‎plet. Also, the variations of Weber number an‎d supercooling temperature were studied numerically. The dro‎plet impact an‎d freezing process were simulated with the volume of fluid method an‎d freezing model. A more accurate simulation was achieved by modeling the supercooled dro‎plet an‎d the dynamic contact angle. At the given ranges of the input parameters, the main factors that guaranteed dro‎plet rebounding after collision were determined. The supercooling temperature an‎d the groove width should be above 266 K an‎d less than 0.21 mm, respectively. The dro‎plet should also maintain its cohesion an‎d integrity during impact. Creating grooves on a surface is novel an‎d paves a new way to understan‎d the impact an‎d solidification of water dro‎plets in supercooled conditions. In the second part of this study, for the first time, the effects of the air transverse flow (ATF) on the thermal-fluid behavior of a supercooled dro‎plet were investigated numerically. Also, different patterns of a superhydro‎phobic pillared surface were used in 24 three-dimensional simulations in ANSYS Fluent software. The volume of fluid method is chosen for the simulation of the multiphase flow. The ATF forces, the freezing effects, an‎d the surface tension forces are included in the Navier-Stokes equations. The freezing model is improved by the supercooling temperature consideration method. The results show that the ATF velocity reduces the separation time exponentially an‎d helps the dro‎plet bounce from the surface before freezing inception. However, the excessive increase in ATF velocity has the opposite effect an‎d may prevent the dro‎plet from detaching the surface due to notable drag. The best value of the ATF velocity is obtained to be 8 m/s, which reduces the separation time exponentially from 16.3 ms to 12.5 ms for a cold surface with a simple pillar pattern. The separation time is entirely affected by the simulation conditions an‎d varies from 11.85 ms to 29.2 ms. The maximum spreading factor, despite the separation time, is seriously influenced by the void fraction percentage of different pillared surfaces an‎d varies from 1.53 to 1.69.

يخ گريزي , قطره فوق سرد , برخورد قطره به سطح , تغيير فاز قطره , مورفولوژي سطح , جريان هواي عرضي , روش حجم سيال

: Icephobicity , Supercooled dro‎plet , dro‎plet-surface impact , dro‎plet phase change , Air transverse flow , Volume of fluid method , Surface morphology

Seyed Reza Hosseini

Dr. Nouri & Dr. Moghimi