Use of MADYMO CFD for Driver Out of Position Simulation

CAE tools have been broadly used to capture and predict interactions between dummies and airbags in detail with the advantages of less preparation time for test set-up and less variability in results especially during airbag deployment tests with dummies out of position. But, the time spent to fold airbag mesh, validate CAE airbag models to experiments and long turn-around times have often been a deterrent to fully adopting CAE tools as a effective way to develop airbag performance. It has been a few years since MADYMO implemented Computational Fluid Dynamics, or CFD into an airbag deploying algorithm. In the early stage of MADYMO CFD, there were issues such as a restriction on the maximum number of Euler cells and instability of unfolding airbags, however, with the introduction of MADYMO V6.2. it has improved CFD functionalities (i.e. more realistic predictions and more stable and accurate simulations). In this study, MADYMO Computer Fluid Dynamics was utilized to predict unfolding kinematics of folded driver side airbags and evaluated to see how well the MADYMO CFD captures dummy responses and bag kinematics, etc. compared to conventional uniform pressure airbag simulations. A 5th percentile female dummy in NHTSA Out-of-position #2 was seated on the driver side and the driver side airbag was folded and deployed. The results from CFD analysis were compared to both an experiment and a uniform pressure bag simulation.