CFD-Simulation and Validation of Cabin Pressure during Door Closing Motions

Under the competitive pressure of automotive industry the customer’s focus is on a vehicle’s quality perception. Side door closing efforts make a considerable share of the overall impression as the doors are the first physical and haptic interface to the customer. Customer’s subjective feeling of vehicle quality demands for detailed analysis of each contributor of door closing efforts. Most contributors come from kinematic influences. Beside the losses due to mechanical subsystems like the checkarm, latch or hinge friction one of the biggest impacts originates from the pressure spike that builds up due to air being pushed into the cabin. Subject of this publication is to discuss the dependencies of closing efforts on cabin pressure and air extraction. It demonstrates an approach to simulate the development of the air pressure during door closing motions and the validation of the simulation method with the “EZ-Slam” measurement device. In order to produce a correlation between simulation and reality a simplified model of a vehicle cabin is created. The validation tests are conducted on a physical test rig, built exactly according to the model, and the CFD simulation is done on the CAD model of the rig. In order to show a correlation between the CFD method and the physical test procedure a set of influencing parameters is identified and tested for its impact on the pressure spike.