/FVMBAG/MODIF

Engine Keyword Activates FVM airbag merging parameter modifications in Engine file.

Format

/FVMBAG/MODIF

monvol_ID

Igmerg Cgmerg Cnmerg Ilvout

Definitions

Data Description SI Unit Example
monvol_ID Finite Volume Method monitored volume identification number.

(Integer)

 
Igmerg Global merging formulation flag. 1
=1 (Default)
Mean volume use the current mean volume.
=2
Mean volume use the initial mean volume.

(Integer)

 
Cgmerg Factor for global merging. 1

(Real)

 
Cnmerg Factor for neighborhood merging. 1

(Real)

 
Ilvout Output level:
0 (Default)
1

(Integer)

 

Comments

  1. When a finite volume fails during the inflation process of the airbag (volume becoming negative, internal mass or energy becoming negative), it is merged to one of its neighbors so that the calculation can continue. Two merging approaches are used:
    • Global merging: a finite volume is merged if its volume becomes less than a certain factor multiplying the mean volume of all the finite volumes. The flag Igmerg determines if the mean volume uses the current mean volume (Igmerg =1) or the initial mean volume (Igmerg =2). The factor giving the minimum volume from the mean volume is Cgmerg.
    • Neighborhood merging: a finite volume is merged if its volume becomes less than a certain factor multiplying the mean volume of its neighbors. The factor giving the minimum volume from the mean volume is Cnmerg.

    If both Cgmerg and Cnmerg are not equal to 0, merging approach will be used simultaneously.