In the automotive industry, the perceived quality of a vehicle is heavily influenced by the ease and effort required to close its doors (which is governed by total door closing energy), particularly when all windows and other doors are closed. A major contributor to increased door closing energy is the air bind energy, a phenomenon caused by the rapid compression of trapped air within a sealed vehicle cabin during door closure. Studies have shown that this transient event leads to a significant rise in cabin pressure.
This study presents a Computational Fluid Dynamics (CFD) method to evaluate the impact of air bind energy on door closing during the early stages of vehicle design. By simulating the cabin pressure dynamics during door closure, the research identifies key parameters influencing the air bind energy, such as door closing velocity, pressure relief valve and airflow escape paths. Other mechanical factors like hinge friction, check arm, and door seal etc. are excluded from the CFD model due to their complexity in simulation.
The proposed CFD method is validated using three different vehicle models with varying door closing speeds. Cabin pressure vs time results are compared against physical tests conducted with the EZ-Slam measurement device. The strong correlation between CFD results and physical test data confirms the robustness of this method.
Research findings highlight that optimizing the placement & size of pressure relief valve can significantly reduce the air bind energy, thereby lowering the total door closing energy. This is achieved by reducing cabin peak pressure and maximizing the rate at which peak pressure reaches atmospheric conditions. These insights are valuable for automotive engineers, to improve customer satisfaction through reduced door closing effort.