/MAT/LAW151 (MULTIFLUID)

Block Format Keyword Simulation of multi-fluid compressible flows by defining a sub-material and initial volume fraction.

Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
/MAT/LAW151/mat_ID or /MAT/MULTIFLUID/mat_ID
mat_title
Blank
mat_ID1 Vol_frac1
etc etc
mat_IDN Vol_fracN

Definition

Field Contents SI Unit Example
mat_ID Material identifier.

(Integer, maximum 10 digits)
mat_title Material title.

(Character, maximum 100 characters)
Repeat the following two lines for each material 1 through N
Field Contents SI Unit Example
mat_IDi Sub-material identifier. 1

(Integer, maximum 10 digits)
Vol_fraci Volume fraction. 2

(Real)

Example (Multi Air)

#RADIOSS STARTER
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/UNIT/1
unit for mat
                   g                  mm                  ms
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#-  2. MATERIALS:
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/MAT/MULTIFLUID/40/1
MULTI_AIR
# initial air

         4                 1.0
         5                 0.0
/ALE/MAT/40
#     Modif. factor.
                   0                                                                  
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/MAT/MULTIFLUID/50/1
MULTI_WATER
# initial water

         4                 0.0
         5                 1.0
/ALE/MAT/50
#     Modif. factor.
                   0                                            
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/MAT/HYD_VISC/4/1
AIR_LAW6
#              RHO_0
             1.22E-6
#                Knu                Pmin
                   0                   0
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/EOS/POLYNOMIAL/4/1
AIR
#                 C0                  C1                  C2                  C3
                   0                   0                   0                   0
#                 C4                  C5                  E0                 Psh               RHO_0
                  .4                  .4                 .25                   0             1.22E-6
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|				   
/MAT/HYD_VISC/5/1
Water_LAW6
#              RHO_0
                .001
#                Knu                Pmin
                   0                   0
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/EOS/POLYNOMIAL/5/1
WATER - LINEAR
#                 C0                  C1                  C2                  C3
                   0                2250                   0                   0
#                 C4                  C5                  E0                 Psh               RHO_0
                   0                   0                   0                   0                .001
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#ENDDATA

Comments

  1. Compatible material laws are LAW6: hydrodynamic law with any equation of state (/EOS), and LAW5 (explosive material).
  2. The sum of volume fraction input for all materials must be equal to 1; except when the volume fraction fields are initialized using the /INIVOL option.
  3. Eulerian and ALE solutions are available.
  4. LAW151 uses a colocated finite volume integration solver.
  5. Planar and axisymmetric 2D simulations can use /QUAD and /TRIA elements.
  6. 3D simulations can use /BRICK and /TETRA4 elements.
  7. Default boundary conditions are sliding wall. Non-reflecting outlet and inlets can be used with /EBCS/FLUXOUT and /EBCS/INLET options.
  8. Initial velocities can be set using /INIVEL/FVM option.
  9. Initial volume fractions can be set using the /INIVOL card.
  10. Fluid structure interaction interfaces TYPE1 and TYPE18 (/PARITH/OFF only) are compatible with LAW151.
  11. Direct contact (node to node coincidence) between a Lagrangian part and an EULER or ALE LAW151 part can be used for small displacement FSI problems.
  12. For stable results, the time step scale factor should be less than 0.5.