/MAT/LAW46 (LES

Format

(1)	(2)	(3)	(4)
/MAT/LAW46/`mat_ID`/`unit_ID` or /MAT/LES_FLUID/`mat_ID`/`unit_ID`
`mat_title`
$ρ_{i}$ $ρ_{i}$		$ρ_{0}$ $ρ_{0}$
`c`		$ν$ $ν$
`I`_sgs	`Cs`		`Csp`

Definition

Field	Contents	SI Unit Example
`mat_ID`	Material identifier. (Integer, maximum 10 digits)
`mat_title`	Material title. (Character, maximum 100 characters)
`unit_ID`	Unit Identifier. (Interger, maximum 10 digits)
$ρ_{i}$ $ρ_{i}$	Initial density. (Real)	$[\frac{kg}{m^{3}}]$ $[\frac{kg}{m^{3}}]$
$ρ_{0}$ $ρ_{0}$	Reference density used in E.O.S (equation of state). Default $ρ_{0} = ρ_{i}$ $ρ_{0} = ρ_{i}$ (Real)	$[\frac{kg}{m^{3}}]$ $[\frac{kg}{m^{3}}]$
`c`	Speed of sound. (Real)	$[\frac{m}{s}]$ $[\frac{m}{s}]$
$ν$ $ν$	Molecular kinematic viscosity. (Real)	$[\frac{m^{2}}{s}]$ $[\frac{m^{2}}{s}]$
`I`_sgs	Sub-grid scale model. = 0 No sub-grid viscosity. = 1 (Default) Smagorinsky model. = 2 Smagorinsky with acoustic damping. = 3 Identical to `I`_sgs =2 with modified $Δ$ $Δ$ value. (Integer)
`Cs`	Smagorinsky constant. Default = 0.1 (Real)
`Csp`	Pressure damping coefficient. Default = Cs (Real)	$[\frac{1}{s}]$ $[\frac{1}{s}]$

▸Example (Fluid)

#RADIOSS STARTER
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/MAT/LAW46/5
FLUID (unit: kg_m_s)
#              RHO_I
              1562.5
#                  c                  NU
               593.3              2.4e-6
#     Isgs                 C_s                 Csp
         2                   0                   0
/EULER/MAT/5
#     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

For I_sgs = 1 or 2, $Δ = \sqrt[3]{Volume}$ $Δ = \sqrt[3]{Volume}$ .
For I_sgs = 3, $Δ$ $Δ$ is the smallest dimension of each element.
$ν_{sgs}$ $ν_{sgs}$ is computed as:(1)
$ν_{sgs} = {(Cs Δ)}^{2} {(e_{ij})}^{\frac{1}{2}}$ $ν_{sgs} = {(Cs Δ)}^{2} {(e_{ij})}^{\frac{1}{2}}$
This law is modified near wall boundaries:
$ν + ν_{sgs} = \frac{ν \cdot k \cdot y_{2}^{+}}{\ln (E y_{2}^{+})}$ $ν + ν_{sgs} = \frac{ν \cdot k \cdot y_{2}^{+}}{\ln (E y_{2}^{+})}$ if $y_{2}^{+} \geq 11.225$ $y_{2}^{+} \geq 11.225$

$ν_{sgs} = 0$ $ν_{sgs} = 0$ , otherwise.

Where,

$ν_{sgs}$ $ν_{sgs}$

Sub grid scale viscosity

$k$ $k$

von Kahrman constant

/MAT/LAW46 (LES_FLUID)

Format

Definition

▸Example (Fluid)

Comments