Development of a backflow simulation program for automotive body assemblies

Most car body parts are manufactured using thin plates to reduce their weight, and completed assemblies typically have numerous spaces. Because cars are not designed to be completely watertight, rain or wash water may leak into the interior spaces of the assembly through gaps or inlets. When water enters a space and is not drained sufficiently, it can fill the space and overflow into unexpected channels, causing severe problems such as part corrosion and electric shock. In our research, based on a decomposition model representation, we have developed a program to graphically simulate all possible flows within the interior spaces between car parts. Our program can simulate the locations of outlets and overflow channels into unexpected regions, and thus help designers verify the effectiveness of their designs before manufacturing, which can therefore reduce the development time and costs. In particular, since the program can simulate overflow when a car in both horizontal and inclined positions, it can prevent possible design errors by engineers who are accustomed to designing cars only in a horizontal orientation. Our developed method can also be applied to aircraft and ship designs.