# Jetting Effect

The jetting effect is modeled as an overpressure applied to each element of the airbag (Figure 1).

$\text{Δ}{P}_{jet}=\text{Δ}{P}_{1}\left(t\right).\text{Δ}{P}_{2}\left(\theta \right).\text{Δ}{P}_{3}\left(\delta \right).\mathrm{max}\left(\stackrel{\to }{n}.{\stackrel{\to }{n}}_{1},0\right)$

with:
${\stackrel{\to }{n}}_{1}$
Being the normalized vector between the projection of the center of the element upon segment ( ${N}_{1}$ , ${N}_{3}$ ) and the center of element as shown in Figure 1.
$\theta$
The angle between the vector ${\stackrel{\to }{MN}}_{2}$ and the vector ${\stackrel{\to }{n}}_{1}$ .
$\delta$
The distance between the center of the element and its projection of a point upon segment ( ${N}_{1}$ , ${N}_{3}$ ).
The projection upon the segment ( ${N}_{1}$ , ${N}_{3}$ ) is defined as the projection of the point in direction ${\stackrel{\to }{MN}}_{2}$ upon the line ( ${N}_{1}$ , ${N}_{3}$ ) if it lies inside the segment ( ${N}_{1}$ , ${N}_{3}$ ). If this is not the case, the projection of the point upon segment ( ${N}_{1}$ , ${N}_{3}$ ) is defined as the closest node ${N}_{1}$ or ${N}_{3}$ . If ${N}_{3}$ coincides to ${N}_{1}$ , the dihedral shape of the jet is reduced to a conical shape.