Investigation Of The Process Of Alumina Droplets Impinging On The Wall

The phenomenon of droplets hitting the wall is a common phenomenon in daily life and industrial applications.Among them,the phenomenon of high-temperature molten droplets hitting the wall is common in blast furnace slag,solid rocket motors and other fields.The collision process between the high-temperature molten droplet and the wall is a multi-physics coupling process with heat transfer and force interaction,and may be accompanied by the phase transition of the droplet and the chemical reaction between the liquid walls.When molten droplets hit the wall,there are different behavior modes,which phenomena such as rebound,deposition,splashing,etc.may occur,showing different states of action on the wall,which affect the working environment and boundary state of the wall.In addition,the impact of hightemperature molten droplets on the wall will cause slag deposition and erosion of the wall.The phenomenon of high-temperature molten droplets hitting the wall may cause the safety of the wall thermal structure to fail.Therefore,the phenomenon of high-temperature molten droplets hitting the wall has a great influence in related fields and cannot be ignored.The relevant research is of great significance.Due to the characteristics of high temperature,high surface tension and high viscosity of molten droplet,which are different from the phenomenon of conventional droplet bumping.The experimental research methods of molten droplets are difficult to achieve,and numerical methods are more effective research methods.Aiming at the problem of alumina droplets hitting the wall,in this paper,the process of alumina droplet impinging on the wall was numerically studied by using VOF method.The main research contents are as follows:First,aiming at the process of alumina droplets with different particle sizes and initial velocities hitting the wall surface vertically,an axisymmetric model was established to carry out a numerical study,and the influence of particle size and initial velocity on the droplet behavior pattern was analyzed.Finally,according to Sommerfeld criterion,the critical conditions of the behavior mode conversion when the alumina droplet hits the wall vertically are obtained;Secondly,the axisymmetric model is used to numerically study the two-phase flow field of the different behavior mode of the droplet,and the morphology,pressure field and velocity field changes of the different behavior mode when the droplet hitting the wall vertically is analyzed.The study found that the behavior mode of the droplet from rebound to deposition to splashing.In the initial stage of the droplet hitting the wall,the local inertia of the droplet gradually increases;Finally,aiming at the process of alumina droplets obliquely hitting the wall surface.,a three-dimensional model was established for numerical research.According to the analysis of the calculation results,the impact characteristics of the alumina droplets at different incident angles are discussed.Finally,it is concluded that increasing the incident angle can suppress the splashing of droplets.