Study Of Droplets Impact On Rough And Inclined Wall With Lattice Boltzmann Method

The behavior of droplet impacting solid wall has important significance in manyengineering fields. Due to the complexity of problem, traditional methods are difficult tosimulate this kind of problem. Because the lattice Boltzmann method is easy to capturephase interface and can depict the reaction accurately, we will regard it as the mainmethod in this paper. In order to verify the feasibility of the model, this paper determinedthe surface tension by linear fitting for different viscosity ratio. Furthermore we use thismodel to determine the contact angle of the wall to verify the correctness of the model interms of simulation for multicomponent flow. Finally, we simulate the dynamic behaviorof the droplet hitting the inclined and rough wall, then analyze the impact of relevantproperties of wall and droplet.The main conclusions in this paper are as follows. In terms of the property of thewall, smoother a wall is, faster the droplet will spread on the wall, larger the maximumspreading area will be and more remains on the wall. Better wetting wall results in thesame situation. Higher inclination results in shorter time for droplet detaching, lessremains on the wall, but larger maximum spreading area. In terms of the property ofdroplet, higher the impacting speed of the droplet, less remains will be on the wall. Ourexperiment have found that the relation of impacting speed and the maximum spreadingarea are nonlinear. For example, the impacting speed causing the maximum spreadingarea in our experiment is about0.05. Meanwhile we found the size of droplet has nosignificance relationship with the quantity of the remains on the wall. The viscosity ratioof multicomponent flow has no discernible effect on the speed of detaching. However,smaller viscosity ratio results in smaller maximum spreading area and less remains on thewall after the impact. Besides qualitative research is done on the critical Bound numberof droplet separation. Higher Bound number results in larger maximum spreading area and less remains will be on the wall.