Volume Generation and Managing

One of the most important difficulties in the airbag deployment simulation is how the gas mesh is managed for the gas flow calculation. In fact, the gas mesh must be correct from the beginning when the airbag is folded, to the end when the airbag is completely opened.

The discretization of the internal volume of the airbag is achieved through a set of general polyhedra (finite volumes). Some of this polyhedra can be entered by you through a group of solids, located inside the airbag and filling a part, or the entire internal volume. If a part of the internal volume is not discretized by user-defined solids, an automatic meshing procedure fills it with polyhedra. Managing irregular polyhedra may be possible to split or merge them, depending on the different criteria to avoid negative or bad volume which may appear during the run.

The polyhedra is consist in a set of triangular facets. Their vertices do not necessarily coincide with nodes of the airbag fabric.

Figure 1.