/MAT/K-EPS
Block Format Keyword Describes the turbulence viscous material for fluid.
Format
(1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) |
---|---|---|---|---|---|---|---|---|---|
/MAT/K-EPS/mat_ID/unit_ID | |||||||||
mat_title | |||||||||
Pmin | |||||||||
SSL | |||||||||
E |
Definitions
Field | Contents | SI Unit Example |
---|---|---|
mat_ID | Material identifier (Integer, maximum 10 digits) |
|
unit_ID | Unit Identifier (Integer, maximum 10 digits) |
|
mat_title | Material title (Character, maximum 100 characters) |
|
Initial density (Real) |
||
Reference density used in E.O.S (equation of
state). Default = (Real) |
||
Kinematic viscosity (Real) |
||
Pmin | Pressure cut-off. (Real) |
|
Initial turbulent energy (first
part). (Real) |
||
SSL | Subgrid scale length (first part). Default = 1e+10 (Real) |
|
Turbulent viscosity coefficient (second
part). Default = 0.09 (Real) |
||
k
diffusion coefficient (second part). Default = 1.00 (Real) |
||
Prandtl number of dissipation (second
part). Default = 1.30 (Real) |
||
Laminar/turbulent Prandtl ratio (second
part). Default = 0.7/0.9 (Real) |
||
equation coefficient 1 (third
part). Default = 1.440 (Real) |
||
equation coefficient 2 (third
part). Default = 1.920 (Real) |
||
equation coefficient 3 (third
part). Default = -0.375 (Real) |
||
Kappa wall constant (fourth part). Default = 0.4187 (Real) |
||
E | E wall constant (fourth
part). Default = 9.7930 (Real) |
|
α |
,
,
excentration (fourth
part). Default = 0.5000 (Real) |
|
Source term factor (fourth
part). (Real) |
Example (Gas)
#RADIOSS STARTER
/UNIT/1
unit for mat
kg m s
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/MAT/K-EPS/4/1
GAS
# RHO_I RHO_0
.3828 0
# KNU Pmin
1.05E-4 0
# RHO0_K0 SSL
20 0
# C_MU SIG_k SIG_EPS P_R_ON_P_RT
0 0 0
# C_1eps C_2eps C_3eps
0 0 0
# KAPPA E ALPHA GSI_T
0 0 0 0
/EOS/POLYNOMIAL/4/1
GAS
# C0 C1 C2 C3
0 0 0 0
# C4 C5 E0 Pmin RHO_0
0.4 0.4 253300 0 1.22
/ALE/MAT/4
# Modif. factor.
0
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#enddata
/END
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
Comments
-
(1) Where,- Deviatoric stress tensor
- Deviatoric strain tensor
- If the element is connected to a boundary
condition, a turbulent boundary layer model is used:
(2) (3) (4) Where, is the turbulent kinetic energy.
- If the ratio between the laminar and the
turbulent Prantl numbers is higher than
, then:
- For laminar flow:
(5) - For turbulent flow:
(6)
Where, is the turbulent dissipation and it is calculated using the following equations:(7) With,
(turbulent viscosity)(8) (9) Where,- Material velocity
- Grid velocity
- For laminar flow:
- Equation of state for hydrodynamic
pressure has to be prescribed via the
/EOS card.
If , then , so
Where,- Dilatation coefficient
- Dilatation
- If using LAW6 coupled with /MAT/LAW37 (BIPHAS) for liquid
phase (without gas phase), the compatibility of
the liquid EOS is:
for LAW6, via a polynomial EOS defined in the example above,
then,
- If using LAW6 coupled with /MAT/LAW37 (BIPHAS) for gas
phase (without liquid phase), the compatibility of
the gas EOS is:
, for LAW6, via the /EOS/IDEAL-GAS equation of state.
Where, is the energy per unit volume.
- All thermal data ( ) can be defined with keyword /HEAT/MAT.