/MONVOL/LFLUID
Block Format Keyword Describes the pressure of a linear fluid using a monitored volume.
Format
(1)  (2)  (3)  (4)  (5)  (6)  (7)  (8)  (9)  (10) 

/MONVOL/LFLUID/monvol_ID/unit_ID  
monvol_title  
surf_ID_{ex}  
Ascale_{t}  Ascale_{P}  
$\rho $  
fct_K  fct_Mt_{in}  Fscale_K  Fscale_Mt_{in}  
fct_Mt_{out}  fct_Mp_{out}  Fscale_Mt_{out}  Fscale_Mp_{out}  
fct_P_{add}  fct_P_{max}  Fscale_P_{add}  Fscale_P_{max} 
Definitions
Field  Contents  SI Unit Example 

monvol_ID  Monitored volume
identifier (Integer, maximum 10 digits) 

unit_ID  Unit Identifier (Integer, maximum 10 digits) 

monvol_title  Monitored volume
title (Character, maximum 100 characters) 

surf_ID_{ex}  External surface
identifier. (Integer) 

Ascale_{t}  Abscissa scale factor for
time based functions. Default = 1.0 (Real) 
$\left[\text{s}\right]$ 
Ascale_{P}  Abscissa scale factor for
pressure based functions. Default = 1.0 (Real) 
$\left[\text{Pa}\right]$ 
$\rho $  Fluid
density. (Real) 
$\left[\frac{\text{kg}}{{\text{m}}^{\text{3}}}\right]$ 
fct_K  Load curve identifier for
bulk modulus
$K\left(t\right)$
. (Integer) 

Fscale_K  Load curve scale factor for bulk modulus or constant bulk modulus. 7  $\left[\text{Pa}\right]$ 
fct_Mt_{in}  Load curve identifier for
input mass flow rate
${\dot{m}}_{in}\left(t\right)$
. (Integer) 

Fscale_Mt_{in}  Load curve scale factor for input mass flow rate or constant input mass flow rate. 7  $\left[\frac{\text{kg}}{\text{s}}\right]$ 
fct_Mt_{out}  Load curve identifier for
mass flow rate
${\dot{m}}_{out}\left(t\right)$
. (Integer) 

Fscale_Mt_{out}  Load curve scale factor for output mass flow rate or constant output mass flow rate. 7  $\left[\frac{\text{kg}}{\text{s}}\right]$ 
fct_Mp_{out}  Load curve identifier for
output mass flow rate
${\dot{m}}_{out}\left(p\right)$
as a function of
pressure. (Integer) 

Fscale_Mp_{out}  Load curve scale factor for output mass flow rate or constant output mass flow rate. 7  $\left[\frac{\text{kg}}{\text{s}}\right]$ 
fct_P_{add}  Load curve identifier for
additional pressure
${P}_{add}\left(t\right)$
. (Integer) 

Fscale_P_{add}  Load curve scale factor for additional pressure or constant additional pressure. 7  $\left[\frac{\text{kg}}{\text{s}}\right]$ 
fct_P_{max}  Load curve identifier for
maximum pressure
${P}_{\mathrm{max}}\left(t\right)$
. (Integer) 

Fscale_P_{max}  Load curve scale factor for maximum pressure or constant maximum pressure. 7  $\left[\text{Pa}\right]$ 
Comments
 The pressure inside the
monitored volume is defined as:
(1) $$P\left(t\right)=K\left(t\right)\cdot \mathrm{ln}\left(\frac{{V}_{0}\left(t\right)}{V\left(t\right)}\right)+{P}_{add}\left(t\right)$$  surf_ID_{ex} must be defined using segments associated with 4 or 3nodes shell elements (possibly void elements) and not with /SURF/SEG.
 The shell elements that define the surface of the monitored volume should not be deleted or eroded.
 The volume must be closed and the normals must be oriented outwards.
 Abscissa scale factors are
used to transform abscissa units in airbag functions, for
example:
(2) $$f\left(t\right)={\mathrm{f}}_{}\left(\frac{t}{Ascal{e}_{t}}\right)$$Where, $t$ is the time.(3) $$f\left(p\right)=f\left(\frac{p}{Ascal{e}_{P}}\right)$$Where, $p$ is the pressure.
 Fluid mass is computed
as:
(4) $$m\left(t\right)=m\left(0\right)+{\displaystyle {\int}_{0}^{t}{\dot{m}}_{in}\left(t\right)dt}{\displaystyle {\int}_{0}^{t}{\dot{m}}_{out}^{}\left(t\right)dt}{\displaystyle {\int}_{0}^{t}{\dot{m}}_{out}^{}\left(p\right)dt}$$  If the load curve identifier
fct_ is defined, then the Fscale_ is a
scale factor for the load curve with a default value = 1.0:
$K(t)=Fscale\_K\cdot fct\_K$
If the load curve identifier fct_ is not defined, then Fscale_ defines a constant input value:
$K(t)=Fscale\_K$