Abstract: To enhance driving safety in rainy conditions and reduce the contamination of side windows by rainwater, improving the driver's visibility is a crucial aspect of vehicle design. This paper utilizes a liquid film model and a Lagrangian model, and introduces a Volume of Fluid (VOF) model, successfully simulating the water accumulation phenomenon on the side windows of a certain SUV, achieving an accurate depiction of the rainwater flow, accumulation, and wiping process. By defining various interaction modes between the water phase and air phase, and adjusting empirical coefficients, the stability and accuracy of the simulation have been effectively enhanced. In addition, this paper has developed a novel method for simulating the motion of wiper blades, overcoming the instability of traditional methods and significantly improving computational efficiency. Using this method for numerical simulation of side window rainwater contamination under different styling schemes and vehicle speeds, the results are highly consistent with experimental outcomes, verifying the reliability and effectiveness of the method.