Comparison of two Multiphase Procedures on a Commercial Vehicle in Rain Conditions

In automotive design, the study of the water thin layer over a car due to rain is becoming increasingly important: the challenge is to obtain a way to describe the behavior of the water over a vehicle in rainy conditions and its interactions with wipers and drainage systems, to determine potential failures of the vehicle design. In this paper two similar numeric procedures have been realized with the software STAR CCM+® to analyze the dynamic of water thin layer starting from the impingement of the rain on the car surface and taking into account even the motion of the wipers over the windshield. Moreover, the water that flows through the drainage systems is monitored to figure out if the water could produce a malfunction of components near them. In order to describe each status of the water, many multiphase models are used. These methodologies have been applied on a commercial vehicle model and the results have been examined and compared to each other. The analysis shows a better description of the reality for one of them, leading to the possibility of using it as a design tool in the automotive industry.