Ityp = 0
Block Format Keyword This law enables to model a gas inlet condition by providing data from stagnation point. Gas is supposed to be a perfect gas. Input card is similar to /MAT/LAW11 (BOUND), but introduces two new lines to define turbulence parameters.
Format
(1)  (2)  (3)  (4)  (5)  (6)  (7)  (8)  (9)  (10) 

/MAT/BKEPS/mat_ID/unit_ID  
mat_title  
${\rho}_{i}^{\mathit{stagnation}}$  ${\rho}_{0}^{\mathit{stagnation}}$  
Ityp  P_{sh}  Fscale_{T} 
(1)  (2)  (3)  (4)  (5)  (6)  (7)  (8)  (9)  (10) 

node_ID_{v}  $\gamma $  C_{d}  
fct_ID_{ $\rho $ }  
fct_ID_{p}  ${P}_{0}^{\mathit{stagnation}}$  
Blank Format  
${\rho}_{0}{\kappa}_{0}$  ${\rho}_{0}{\epsilon}_{0}$  fct_ID_{k}  fct_ID_{ $\text{\epsilon}$ }  
${C}_{\mu}$  ${\sigma}_{\kappa}$  ${\sigma}_{\epsilon}$  ${P}_{r}/{P}_{rt}$  
fct_ID_{T}  fct_ID_{v} 
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) 

${\rho}_{i}^{\mathit{stagnation}}$  Initial stagnation
density. (Real) 
$\left[\frac{\text{kg}}{{\text{m}}^{\text{3}}}\right]$ 
${\rho}_{0}^{\mathit{stagnation}}$  Reference density used in
E.O.S (equation of state). Default ${\rho}_{0}^{\mathit{stagnation}}={\rho}_{i}^{\mathit{stagnation}}$ (Real) 
$\left[\frac{\text{kg}}{{\text{m}}^{\text{3}}}\right]$ 
Ityp  Boundary condition type.
1
(Integer) 

P_{sh}  Pressure shift. 2 (Real) 
$\left[\text{Pa}\right]$ 
Fscale_{T}  Time scale factor. 3 (Real) 

node_ID_{v}  Node identifier for velocity computation. 3
(Integer) 

$\gamma $  Perfect gas
constant. (Real) 

C_{d}  Discharge coefficient.
5 Default = 0.0 (Real) 

fct_ID $\rho $  Function
${\text{f}}_{\rho}\left(t\right)$
identifier for stagnation density.
3
(Integer) 

fct_ID_{p}  Function
${\text{f}}_{P}(t)$
identifier for stagnation pressure.
3
(Integer) 

${P}_{0}^{\mathit{stagnation}}$  Initial stagnation
pressure. 3 (Real) 
$\left[\text{Pa}\right]$ 
${\rho}_{0}{\kappa}_{0}$  Initial turbulent
energy. (Real) 
$\left[\text{J}\right]$ 
${\rho}_{0}{\epsilon}_{0}$  Initial turbulent
dissipation. (Real) 
$\left[\text{J}\right]$ 
fct_ID_{k}  Function
${\text{f}}_{\kappa}(t)$
identifier for turbulence
modeling.
(Integer) 

fct_ID_{ $\text{\epsilon}$ }  Function
${\text{f}}_{\epsilon}\left(t\right)$
identifier for turbulence
modeling.
(Integer) 

${C}_{\mu}$  Turbulent viscosity
coefficient. Default = 0.09 (Real) 

${\sigma}_{\kappa}$  Diffusion coefficient for
k parameter. Default = 1.00 (Real) 

${\sigma}_{\epsilon}$  Diffusion coefficient for
$\text{\epsilon}$
parameter. Default = 1.30 (Real) 

${P}_{r}/{P}_{rt}$  Ratio between Laminar
Prandtl number (Default 0.7) and turbulent Prandtl number (Default
0.9). (Real) 

fct_ID_{T}  Function
${\text{f}}_{T}\left(t\right)$
identifier for inlet
temperature. 3
6
(Integer) 

fct_ID_{Q}  Function
${\text{f}}_{Q}\left(t\right)$
identifier for inlet heat
flux. 3
6
(Integer) 
Comments
 Provided gas state from stagnation
point
$\left({\rho}_{\mathit{stagnation}},{P}_{\mathit{stagnation}}\right)$
is used to compute inlet gas state.A set of equations including Total Enthalpy formulation, Adiabatic Law and Equation of State allows for the complete definition of the inlet state:
(1) $${\rho}_{\mathit{in}}={\rho}_{\mathit{stagnation}}\cdot {\left[1\frac{\gamma 1}{2\gamma}\cdot \frac{{\rho}_{\mathit{stagnation}}}{{P}_{\mathit{stagnation}}}\cdot (1+{C}_{d})\cdot {\nu}_{\mathit{in}}^{2}\right]}^{\frac{1}{\gamma 1}}$$(2) $${P}_{\mathit{in}}={P}_{\mathit{stagnation}}{\left(\frac{{\rho}_{\mathit{in}}}{{\rho}_{\mathit{stagnation}}}\right)}^{\gamma}$$(3) $${(\rho e)}_{\mathit{in}}=\frac{{P}_{\mathit{in}}}{\gamma 1}$$  The P_{SH} parameter enables shifting the output pressure which also becomes PP_{SH}. If using ${P}_{sh}=P\left(t=0\right)$ , the output pressure will be $\text{\Delta}P$ , with an initial value of 0.0.
 If no function is defined, then related quantity ${P}_{stagnation},{\rho}_{stagnation},T$ or Q remains constant and set to its initial value. However, all input quantities ${P}_{stagnation},{\rho}_{stagnation},T$ and Q can be defined as time dependent function using provided function identifiers. Abscissa functions can also be scaled using Fscale_{T} parameter which leads to use $\mathrm{f}\left(Fscal{e}_{t},t\right)$ instead of $\mathrm{f}\left(t\right)$ .
 Inlet velocity ${v}_{in}^{}$ is used in Bernoulli theory, fixed velocity.
 Discharge coefficient accounts for
entry loss and depends on shape orifice.
 With thermal modeling, all thermal data ( ${T}_{0},{\rho}_{0}{C}_{p}$ , ...) can be defined with /HEAT/MAT.
 It is not possible to use this boundary material law with multimaterial ALE /MAT/LAW37 (BIPHAS) and /MAT/LAW51 (MULTIMAT).