Investigation Of The Droplet Movement On An Inclined Non-piezoelectric Curved Substrate

With the rapid development of automobile intelligence,on-board cameras have become the main way to obtain road information,but water droplets splashing on the lens of the camera in rainy weather severely affect the accuracy of data collection and reduce driving safety.Based on the above problems,this paper proposes a mechanism of droplet movement on a tilted non-piezoelectric curved substrate,which is expected to provide technical support for camera water removal.The movement and spreading of droplets on an inclined curved substrate are affected by various factors,such as the hydrophobicity of the substrate surface,the curvature,the inclination angle,the volume of the liquid itself,the temperature,and the wettability between the liquid and the solid.Aiming at the relationship between the above factors,this article conducts a more in-depth study.In this paper,the theoretical analysis is carried out by using the equations of Navier-Stokes and acoustic streaming force.It is found that under certain input power and droplet volume,the velocities of the droplet at the advancing and receding edges are significantly related to the plate inclination.In addition,when the plate inclination and the droplet volume are fixed,the velocity of the droplet increases with the input power,the higher the input power,the higher the velocities of the advancing and receding edges of the droplet.However,the droplet velocity is not proportional to the droplet volume under certain input power and angle.In addition,when the substrate inclination angle,the input excitation voltage peak value and the water droplet volume are constant,as the curvature increases,the movement speed of the initial stage of the droplet increases more slowly.When a certain time is reached,the speed will rise linearly until the end of the motion.It can be seen from the moving image of the droplet that the moving speed image will show a turning angle,and the larger the curvature,the closer the corner angle is to the right angle.In addition,the paper analyzes the spreading motion of droplets on the curved surface from theoretical and experimental aspects.The effects of droplet volume,impact velocity,droplet properties and substrate inclination angle on the maximum spreading diameter and spreading efficiency of the droplets are studied.The experimental results show that as the volume of the droplet increases,the maximum spreading diameter of the droplet will become larger,but the time used will gradually increase.The larger the impact velocity of the droplet,the larger the maximum spreading diameter of the droplet,the shortertime used.The maximum spreading diameter of ethanol is the largest and the fastest in the case of the same substrate surface,droplet volume and impact velocity,the maximum spreading diameter of olive oil droplets is the smallest,and the longest time is used,water droplets in the middle.The maximum spreading diameter of the droplet will increase slightly with the increase of the inclination angle,but the spreading efficiency of the droplet is improved.