4Way Directional Valve (IL)
4way directional valve in an isothermal liquid system
Description
The 4Way Directional Valve (IL) block models a valve with four openings in an
isothermal liquid network, typically between an actuator, pump, and tank. The valve
operation is controlled by a single spool displaced according to the signal at port
S. You can set the baseline configuration of your valve by
specifying the orifices that are open when the spool is in the neutral position
(centered at 0 m) in the Neutral spool position open connections
parameter, when the spool moves in the positive direction in the Positive
spool position open connections parameter, and when the spool moves in
the negative direction in the Negative spool position open
connections.
You can set the model for valve opening in the Orifice
parameterization parameter as a linear relationship or function of
userprovided data, which can be applied to one or all flow paths in the valve.
In this example configuration, Neutral spool position open
connections is set to All closed
. When the
spool is in the neutral position, all orifices are closed to flow:
In this configuration, Negative spool position open connections
is set to PA and BT
. When the signal at port
S moves the spool to a negative position, the paths between
ports P and A and between ports
B and T are open to flow. The paths
between ports P and B and ports
A and T are closed to flow:
In this configuration, Positive spool position open connections
is set to PB and AT
. When the signal at port
S moves the spool to a positive position, the paths between
ports P and B and between ports
A and T are open to flow and the paths
between ports P and A and between ports
B and T are closed:
Schematically, this configuration is shown as:
Spool Displacement and Valve Configuration
The spool stroke is the amount of spool travel an orifice
takes to fully open from a closed position and is defined for each orifice selected
on the Valve Configuration tab. The table below shows how the
stroke is calculated in accordance with the valve orifice parameterization and flow
path characteristics.
Spool Stroke Based on Parameterization and Flow Path
Orifice Parameterization  Identical for All Flow Paths  Different for Each Flow Path 

Linear  Area vs. spool travel  Defined by the Spool travel between closed and open
orifice parameter  Defined by the Spool travel between closed and open orifice
parameter, for each orifice 
Tabulated data  Area vs. spool travel  The difference between the first and last element of the
Spool travel vector parameter  The difference between the first and last element of the
spool travel vector parameter for each orifice 
Tabulated data  Volumetric flow rate vs. spool travel and
pressure drop  The difference between the first and last element of the
Spool travel vector, ds
parameter  The difference between the first and last element of the
spool travel vector, ds parameter for each orifice 
The section Visualize Orifice Openings details how to
see the orientation of all valve orifices.
The direction of spool movement signaled at port S depends on
the spool stroke and the orifice orientation:
Orifice Definition and Spool Travel Direction
Spool Position when Orifice is Open  Spool Travel, ΔS 

Always closed (orifice is not selected in any spool position
configuration)  N/A 
Always open (orifice is selected in positive, neutral, and
negative spool position configurations)  N/A 
Negative  S_{max} + spool stroke –
S 
Negative and Neutral  S_{max} + spool stroke –
S 
Positive  S_{max} + spool stroke +
S 
Positive and Neutral  S_{max} + spool stroke +
S 
Neutral  S_{max} + spool stroke –
S 
Positive and Negative  –S_{max} + spool stroke
– S 
Where S_{max} is the spool position at the
maximum orifice area defined for each orifice.
The Consistency check for neutral spool position open
connections parameter verifies that
Any orifice listed in Neutral spool position open
connections is open when the signal at
S is 0.
Any orifice that is not listed in Neutral spool position
open connections is closed when the signal at
S is 0.
You can optionally choose to receive a warning or error when this
check is violated.
The possible configurations of the 4Way Directional Valve (IL) block are shown
below.
Note
This block includes all configurations from the Hydraulic (Isothermal)
library blocks 4Way Directional Valve and the 4Way Directional Valves A –
K.
4Way Directional Valve Configuration
Configuration  Parameter Values 

 All four orifices are closed in the neutral position. (default)Positive spool position open
connections: PA and
BT Neutral spool position open
connections: All
closed Negative spool position open
connections: PB and
AT
Spool position at maximum PA orifice
area > PA spool stroke Spool position at maximum PB orifice
area < –PB spool stroke Spool position at maximum AT orifice
area < –AT spool stroke Spool position at maximum BT orifice
area > BT spool stroke

 All four orifices are open in the neutral position.Positive spool position open
connections: PA and
BT Neutral spool position open
connections: PA, PB,
AT, and BT Negative spool position open
connections: PB and
AT
Spool position at maximum PA orifice
area < PA spool stroke Spool position at maximum PB orifice
area > –PB spool stroke Spool position at maximum AT orifice
area > –AT spool stroke Spool position at maximum BT orifice
area < BT spool stroke

 Orifices AT and BT are closed. Orifices PA and PB are overlapped.Positive spool position open
connections: PA
only Neutral spool position open
connections: All
closed Negative spool position open
connections: PB
only

 Orifices AT and BT are open. Orifices PA and PB are overlapped.Positive spool position open
connections: PA and
BT Neutral spool position open
connections: AT and
BT Negative spool position open
connections: PB and
AT
Spool position at maximum PA orifice
area > PA spool stroke Spool position at maximum PB orifice
area < PB spool stroke Spool position at maximum AT orifice
area > –AT spool stroke Spool position at maximum PB orifice
area < BT spool stroke

 Orifices PA and AT are open in the neutral position.
Orifices PB and BT are overlapped.Positive spool position open
connections: PB and
AT Neutral spool position open
connections: PA and
AT Negative spool position open
connections: PA and
BT
Spool position at maximum PA orifice
area < PA spool stroke Spool position at maximum PB orifice
area > PB spool stroke Spool position at maximum AT orifice
area > AT spool stroke Spool position at maximum BT orifice
area < –BT spool stroke

 Orifice AT is open in the neutral position. Orifices PB,
AT, and BT are overlapped.Positive spool position open
connections: PA and
BT Neutral spool position open
connections: AT
only Negative spool position open
connections: PB and
AT
Spool position at maximum PA orifice
area > PA spool stroke Spool position at maximum PB orifice
area < –PB spool stroke Spool position at maximum AT orifice
area > –AT spool stroke Spool position at maximum BT orifice
area > BT spool stroke

 Orifice BT is open in the neutral position. Orifices PA,
PB, and AT are overlapped.Positive spool position open
connections: PA and
BT Neutral spool position open
connections: BT
only Negative spool position open
connections: PB and
AT
Spool position at maximum PA orifice
area > PA spool stroke Spool position at maximum PB orifice
area < –PB spool stroke Spool position at maximum AT orifice
area < –AT spool stroke Spool position at maximum BT orifice
area < BT spool stroke

 Orifices PA and PB are open. Orifices AT and BT are overlapped.Positive spool position open
connections: PA and
BT Neutral spool position open
connections: PA and
PB Negative spool position open
connections: PB and
AT
Spool position at maximum PA orifice
area < PA spool stroke Spool position at maximum PB orifice
area > –PB spool stroke Spool position at maximum AT orifice
area < –AT spool stroke Spool position at maximum BT orifice
area > BT spool stroke

 Orifice PA is open in the neutral position. Orifices PB,
AT, and BT are overlapped.Positive spool position open
connections: PA and
BT Neutral spool position open
connections: PA
only Negative spool position open
connections: PB and
AT
Spool position at maximum PA orifice
area < PA spool stroke Spool position at maximum PB orifice
area < –PB spool stroke Spool position at maximum AT orifice
area < –AT spool stroke Spool position at maximum BT orifice
area > BT spool stroke

 Orifice PB is open in the neutral position. Orifices PA,
AT, and BT are overlapped.Positive spool position open
connections: PA and
BT Neutral spool position open
connections: PB
only Negative spool position open
connections: PB and
AT
Spool position at maximum PA orifice
area > PA spool stroke Spool position at maximum PB orifice
area > –PB spool stroke Spool position at maximum AT orifice
area < –AT spool stroke Spool position at maximum BT orifice
area > BT spool stroke

 Orifices PB and BT are open in the neutral position.
Orifices PA and AT are overlapped.Positive spool position open
connections: PB and
AT Neutral spool position open
connections: PB and
BT Negative spool position open
connections: PA and
BT
Spool position at maximum PA orifice
area < –PA spool stroke Spool position at maximum PB orifice
area < PB spool stroke Spool position at maximum AT orifice
area > AT spool stroke Spool position at maximum BT orifice
area > –BT spool stroke

 Orifices PA, PB, AT, and BT are closed in the neutral
position. PT is open in the neutral position and closes when
the spool displaces.Positive spool position open
connections: PA and
BT Neutral spool position open
connections: PT
only Negative spool position open
connections: PB and
AT
Spool position at maximum PA orifice
area > PA spool stroke Spool position at maximum PB orifice
area < –PB spool stroke Spool position at maximum AT orifice
area < –AT spool stroke Spool position at maximum BT orifice
area > BT spool stroke Spool position at maximum PT orifice
area = any value

 Orifice PA is a constant orifice. Orifices PB, AT, and BT
are open in the neutral position.Positive spool position open
connections: PA and
PB Neutral spool position open
connections: PA, PB,
AT, and BT Negative spool position open
connections: PA and
BT
Spool position at maximum PA orifice
area < PA spool stroke Spool position at maximum PB orifice
area < PB spool stroke Spool position at maximum AT orifice
area = any value Spool position at maximum BT orifice
area > –BT spool stroke

 Orifice PB is a constant orifice. Orifices PA, AT
and BT are open in the neutral position. Positive spool position open
connections: PB and
AT Neutral spool position open
connections: PA, PB,
AT, and BT Negative spool position open
connections: PA and
PB
Spool position at maximum PA orifice
area > –PA spool stroke Spool position at maximum AT orifice
area < AT spool stroke Spool position at maximum BT orifice
area = any value

 Orifice PA is closed in the neutral position. Ports
A and T do not
form a flow path. Positive spool position open
connections: PA and
PB Neutral spool position open
connections: All
closed Negative spool position open
connections: PA and
BT
Spool position at maximum PA orifice
area > PA spool stroke Spool position at maximum PB orifice
area > PB spool stroke Spool position at maximum BT orifice
area < –BT spool stroke

 Orifice PB is closed in the neutral position. Ports
B and T do not
form a flow path. Positive spool position open
connections: PB and
AT Neutral spool position open
connections: All
closed Negative spool position open
connections: PA and
PB
Spool position at maximum PA orifice
area < –PA spool stroke Spool position at maximum PB orifice
area > PB spool stroke Spool position at maximum AT orifice
area > AT spool stroke

 Orifice PA is closed in the neutral position. Orifice
AT is open in the neutral position. Positive spool position open
connections: PA and
PB Neutral spool position open
connections: AT and
BT Negative spool position open
connections: PA and
BT
Spool position at maximum PA orifice
area > PA spool stroke Spool position at maximum PB orifice
area > PB spool stroke Spool position at maximum AT orifice
area = any value Spool position at maximum BT orifice
area > –BT spool stroke

 Orifice PB is closed in the neutral position. Orifice
BT is open in the neutral position. Positive spool position open
connections: PB and
AT Neutral spool position open
connections: AT and
BT Negative spool position open
connections: PA and
PB
Spool position at maximum PA orifice
area < –PA spool stroke Spool position at maximum PB orifice
area > PB spool stroke Spool position at maximum AT orifice
area < AT spool stroke Spool position at maximum BT orifice
area = any value

 Orifice PB is closed in the neutral position. Orifice
PT is open in the neutral position. Ports
A and T do not
form a flow path. Positive spool position open
connections: PA and
PB Neutral spool position open
connections: PT
only Negative spool position open
connections: PB and
AT
Spool position at maximum PA orifice
area > PA spool stroke Spool position at maximum PB orifice
area > PB spool stroke Spool position at maximum BT orifice
area < –BT spool stroke Spool position at maximum PT orifice
area = any value

 Orifice PA is closed in the neutral position. Orifice
PT is open in the neutral position. Ports
A and T do not
form a flow path. Positive spool position open
connections: PA and
BT Neutral spool position open
connections: PT
only Negative spool position open
connections: PA and
PB
Spool position at maximum PA orifice
area > PA spool stroke Spool position at maximum PB orifice
area < –PB spool stroke Spool position at maximum BT orifice
area > BT spool stroke Spool position at maximum PT orifice
area = any value

Valve Orifice Parameterizations
The Orifice parameterization parameter sets the model for the
open area or volumetric flow rate through one or all of the valve orifices. The
block applies the same data for all flow paths if Area
characteristics is set to Identical for all flow
paths
; otherwise, individual parameterizations are applied for the
Different for all flow paths
setting. You can model
valve opening in three ways:
Linear  area vs. spool travel
The opening area is a linear function of the spool position received as a signal at port
S:
where:
Tabulated data  Area vs. spool travel
Provide spool travel vectors for your system or for individual flow paths between ports
P, A, B,
and T. This data will be used to calculate the
relationship between the orifice area and spool displacement. Interpolation
is used to determine the opening area between given data points.
A_{leak} and
A_{max} are the first and last
parameters of the opening area vector, respectively.
Tabulated data  Volumetric flow rate vs. spool travel and
pressure drop
Provide spool travel and pressure drop vectors and a dependent, 2D volumetric flow rate
array. Interpolation is used to determine flow rate between given data
points. The mass flow rate is the product of the volumetric flow rate and
the local density.
Visualize Orifice Openings
To visualize spool offsets and maximum displacement, rightclick on the block and
select > . The plot shows the orifices selected in the Valve
Configuration tab settings. The axes are set by the orifice
parameterization selection and are either:
Orifice Area vs. Spool Position
Volumetric Flow Rate vs. Spool Position, queried at a specific
pressure differential
When the positive, neutral, and negative settings in the
Valve Configuration tab feature the same orifice, the
orifice opening is displayed as a constant.
Each time you modify the block settings, click Apply at the
bottom of the dialog box, then click Reload Data on the
figure window.
The image below shows an example valve configuration. On the Valve
Configuration tab:
Positive spool position open connections is set
to PA and BT
.
Neutral spool position open connections is set to
PT only
.
Negative spool position open connections is set
to PB and AT
.
On the PA Orifice tab:
All other spool positions are at the default values.
The visualization shows that the PA orifice is open between the spool position at
2.53e3
and 2.53e3
m. Due to the
specification that the PA orifice is open only when the spool is displaced in the
positive direction, the Consistency check for neutral spool and position
open connections set to Warning
returns:
Warning: PA orifice must be closed when the spool is in
the neutral position. Adjust Spool position at maximum PA orifice area, Neutral
spool position open connections, or Consistency check for neutral spool position
open connections. Rightclick on the block and select Fluids > Plot Valve
Characteristics to view the area or flow of each connection versus spool
position.
To resolve this warning, you can:
Change the Spool position at maximum PA orifice
area to a value larger than 0.005 m.
Change Consistency check for neutral spool position open
connections to None
.
Change the valve configuration by setting Neutral spool
position open connections to PA
only
.
Ports
Conserving
expand all
A
— Liquid port
isothermal liquid
Liquid entry or exit port to the valve.
B
— Liquid port
isothermal liquid
Liquid entry or exit port to the valve.
P
— Liquid port
isothermal liquid
Liquid entry or exit port to the valve.
T
— Liquid port
isothermal liquid
Liquid entry or exit port to the valve.
Input
expand all
S
— Spool displacement, m
physical signal
Spool displacement, in m, specified as a physical signal.
Parameters
expand all
Valve Configuration
Positive spool position open connections
— Flow paths open when the spool is in a positive position
PA and BT
(default)  PA and PB
 PB and AT
 PA only
 PB only
Flow paths open when the spool is in a positive position. This
parameter sets the valve configuration and defines the direction of
spool movement according to the signal received at port
S. The settings for this parameter can be
checked against the definitions for the other orifices for consistency
when the Consistency check for neutral spool position open
connections is set to Warning
or Error
.
Neutral spool position open connections
— Flow paths open when the spool is in the neutral position
All closed
(default)  PA, PB, AT, and PB
 AT and BT
 PA and AT
 PA and BT
 PA and PB
 PB and AT
 PB and BT
 AT only
 BT only
 PA only
 PB only
 PT only
Flow paths open when the spool is in the neutral position. This
parameter sets the valve configuration and defines the direction of
spool movement according to the signal received at port
S. The settings for this parameter can be
checked against the definitions for the other orifices for consistency
when the Consistency check for neutral spool position open
connections is set to Warning
or Error
.
Negative spool position open connections
— Flow paths open when the spool moves in the negative direction
PB and AT
(default)  PA and BT
 PA and PB
 PA only
 PB only
Flow paths open when the spool moves in the negative direction. This
parameter sets the valve configuration and defines the direction of
spool movement according to the signal received at port
S. The settings for this parameter can be
checked against the definitions for the other orifices for consistency
when the Consistency check for neutral spool position open
connections is set to Warning
or Error
.
Consistency check for neutral spool position open connections
— Whether to check if the orifice settings are consistent with the specified spool position for maximum orifice opening
Warning
(default)  Error
 None
Whether to check if the neutral spool position open settings on the
Valve Configuration tab are consistent with the
specified spool position at the maximum orifice area. For each enabled
orifice, the actual offset at the spool neutral position should be
commensurate with the specified spool offset for each individual
orifice.
Model Parameterization
Area characteristics
— Flow equations for orifices
Identical for all flow
paths
(default)  Different for each flow path
Applies uniform or individual flow equations for the valve orifice
area. Identical for all flow paths
uses the
same orifice and spool geometries, flow rates, pressure, and area
vectors for all valve orifices. When using Different for
each flow path
, these parameters are specified
individually for each orifice. In both cases, orifices
A, B,
P, and T have the same
crosssectional areas, discharge coefficients, and Reynolds numbers in
the Linear  Area vs. spool travel
and
Tabulated data  Area vs. spool travel
parameterizations. The same Orifice
parameterization is applied to all flow paths.
Orifice parameterization
— Method of calculating opening area
Linear area vs. spool
travel
(default)  Tabulated data  Area vs. spool
travel
 Tabulated data  Volumetric flow rate vs. spool travel
and pressure drop
Method of calculating the valve opening area. In the tabulated data
parameterizations, you can provide your own valve area and spool travel
data for nonlinear valve opening profiles, or you can provide data in
terms of volumetric flow rate, spool travel, and pressure drop over the
flow path.
Spool travel between closed and open orifice
— Maximum spool stroke
0.005 m
(default)  positive scalar
Maximum distance of spool travel.
Dependencies
To enable this parameter, set Area
characteristics to Identical for all
flow paths
and Orifice
parameterization to Linear  Area vs.
spool travel
.
Maximum orifice area
— Maximum orifice opening area
1e4 m^2
(default)  positive scalar
Largest open area of each orifice during the operation of the
valve.
Dependencies
To enable this parameter, set Area
characteristics to Identical for all
flow paths
and Orifice
parameterization to Linear  Area vs.
spool travel
.
Leakage area
— Open area when an orifice is fully closed
1e9 m^2
(default)  positive scalar
Open area when an orifice is fully closed. Any area smaller than this
value is maintained at the specified leakage area. This parameter
contributes to numerical stability by maintaining continuity in the
flow.
Dependencies
To enable this parameter, set Orifice
parameterization to Linear  Area vs.
spool travel
.
Spool travel vector
— Vector of spool opening distances relative to fully closed position
[0, .00125, .0025, .00375, .005]
m
(default)  1byn vector
Vector of spool travel distances for the tabular parameterization of
valve area. The vector elements must correspond onetoone with the
elements in the Orifice area vector parameter. The
values are listed in ascending order and the first element must be 0.
Linear interpolation is employed between table data points.
Dependencies
To enable this parameter, set Area
characteristics to Identical for all
flow paths
and Orifice
parameterization to Tabulated data 
Area vs. spool travel
.
Orifice area vector
— Vector of valve opening areas
[1e09, 1e05, 4e05, 6e05, .0001]
m^2
(default)  1byn vector
Vector of opening areas for the tabular parameterization of valve
opening area. The vector elements must correspond onetoone with the
elements in the Spool travel vector parameter. The
elements are listed in ascending order and must be greater than
0.
Dependencies
To enable this parameter, set Area
characteristics to Identical for all
flow paths
and Orifice
parameterization to Tabulated data 
Area vs. spool travel
.
Spool travel vector, ds
— Vector of spool opening distances relative to fully closed position
[0, .00125, .0025, .00375, .005]
m
(default)  1byn vector
Vector of spool travel distances for the tabular parametrization of
volumetric flow rate. The spool travel vector forms an independent axis
with the Pressure drop vector, dp parameter for the
2D dependent Volumetric flow rate table, q(ds,dp)
parameter. The values are listed in ascending order and the first
element must be 0. Linear interpolation is employed between table data
points.
Dependencies
To enable this parameter, set Area
characteristics to Identical for all
flow paths
and Orifice
parameterization to Tabulated data 
Volumetric flow rate vs. spool travel and pressure
drop
.
Pressure drop vector, dp
— Vector of valve pressure drop values
[.1, .3, .5, .7] MPa
(default)  1byn vector
Vector of pressure drop values for the tabular parametrization of
volumetric flow rate. The pressure drop vector forms an independent axis
with the Spool travel vector, ds parameter for the
2D dependent volumetric flow rate table, q(ds,dp)
parameter. The values are listed in ascending order and must be greater
than 0. Linear interpolation is employed between table data
points.
Dependencies
To enable this parameter, set Area
characteristics to Identical for all
flow paths
and Orifice
parameterization to Tabulated data 
Volumetric flow rate vs. spool travel and pressure
drop
.
Volumetric flow rate table, q(ds,dp)
— Array of volumetric flow rates
[1e08, 2.2e08, 2.8e08, 3.4e08; 9e06,
.00015, .0002, .00024; .00036, .00063, .00081, .00096; .00054,
.00094, .0012, .0014; .00091, .0016, .002, .0024]
m^3/s
(default)  MbyN matrix
MbyN matrix of volumetric flow
rates based on independent values of pressure drop and spool travel
distance. M and N are the sizes of
the correlated vectors:
M is the number of vector elements in
the Pressure drop vector, dp
parameter.
N is the number of vector elements in
the Spool travel vector, ds
parameter.
Dependencies
To enable this parameter, set Area
characteristics to Identical for all
flow paths
and Orifice
parameterization to Tabulated data 
Volumetric flow rate vs. spool travel and pressure
drop
.
Constant orifice area
— Orifice area for identical flow paths
1e4 m^2
(default)  positive scalar
Orifice area when the positive, neutral, and negative spool positions
feature the same orifice.
Dependencies
To enable this parameter, set Area
characteristics to Identical for all
flow paths
and Orifice
parameterization to either:
The same orifice must be selected in all three of the
Valve Configuration parameters:
Positive spool position open
connections
Neutral spool position open
connections
Negative spool position open
connections
Constant orifice pressure drop vector
— Vector of pressure differential values for identical flow paths
[.1, .3, .5, .7] MPa
(default)  1byn vector
Vector of pressure differential values over the valve when the
positive, neutral, and negative spool positions feature the same
orifice. The vector elements correspond onetoone with the elements in
the Constant orifice volumetric flow rate vector
parameter. The values are listed in ascending order. Linear
interpolation is employed between table data points.
Dependencies
To enable this parameter, set Area
characteristics to Identical for all
flow paths
and Orifice
parameterization to Tabulated data 
Volumetric flow rate vs. spool travel and pressure
drop
.
The same orifice must be selected in all three of the
Valve Configuration parameters:
Positive spool position open
connections
Neutral spool position open
connections
Negative spool position open
connections
Constant orifice volumetric flow rate vector
— Vector of volumetric flow rate values for identical flow paths
[.0009, .0016, .002, .0024]
m^3/s
(default)  1byn vector
Vector of volumetric flow rate values for a constant orifice when the
positive, neutral, and negative spool positions feature the same
orifice. The vector elements correspond onetoone with the elements in
the Constant orifice pressure drop vector
parameter. The values are listed in ascending order. Linear
interpolation is employed between table data points.
Dependencies
To enable this parameter, set Area
characteristics to Identical for all
flow paths
and Orifice
parameterization to Tabulated data 
Volumetric flow rate vs. spool travel and pressure
drop
.
The same orifice must be selected in all three of the
Valve Configuration parameters:
Positive spool position open
connections
Neutral spool position open
connections
Negative spool position open
connections
Crosssectional area at ports P, T, A and B
— Area at conserving ports
inf m^2
(default)  positive scalar
Maximum crosssectional areas at the entry and exit ports
P, T,
A, and B, which are used
in the pressureflow rate equation that determines the mass flow rate
through the valve.
Dependencies
To enable this parameter, set Area
characteristics to Identical for all
flow paths
and Orifice
parameterization to either:
Discharge coefficient
— Discharge coefficient
0.64
(default)  positive scalar
Correction factor that accounts for discharge losses in theoretical
flows.
Dependencies
To enable this parameter, set Orifice
parameterization to either:
Critical Reynolds number
— Upper Reynolds number limit for laminar flow
150
(default)  positive scalar
Upper Reynolds number limit for laminar flow through the orifice.
Dependencies
To enable this parameter, set Orifice
parameterization to:
Pressure recovery
— Whether to account for pressure increase in area expansions
Off
(default)  On
Whether to account for pressure increase when fluid flows from a
region of smaller crosssectional area to a region of larger
crosssectional area.
Dependencies
To enable this parameter, set Orifice
parameterization to:
PA Orifice
Spool position at maximum PA orifice area
— Spool offset for fully open PA orifice
7.5e3 m
(default)  positive scalar
Spool offset from the neutral position for a fully open PA orifice.
The Consistency check for neutral spool position open
connections parameter will notify you if the values set
for this spool position are inconsistent or unphysical according to
other orifice spool positions. To visualize the defined offsets, see
Visualize Orifice Openings.
Dependencies
To enable this parameter, set one of the following parameters:
Positive spool position open connections to:
PA and BT
PA and PB
PA only
Neutral spool position open
connections to:
PA, PB, AT, and
BT
PA and AT
PA and BT
PA and PB
PA only
Negative spool position open
connections to:
PA, PB, AT, and
BT
PA and AT
PA and BT
PA and PB
PA only
Note:
This parameter is enabled only when the PA orifice
settings do not appear in all three spool position
parameters: Positive spool position
open connections, Neutral spool
position open connections, and Negative spool position open
connections.
PA spool travel between closed and open orifice
— Maximum spool stroke
0.005 m
(default)  positive scalar
Maximum distance of spool travel. This value provides an upper limit
to calculations so that simulations do not return unphysical
values.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Linear  Area vs. spool
travel
.
One of the following parameters:
Positive spool position open
connections to:
PA and
BT
PA and
PB
PA only
Neutral spool position open
connections to:
PA, PB, AT, and
BT
PA and
AT
PA and
BT
PA and
PB
PA only
Negative spool position open
connections to:
PA, PB, AT, and
BT
PA and
AT
PA and
BT
PA and
PB
PA only
PA maximum orifice area
— Maximum orifice opening area
1e4 m^2
(default)  positive scalar
Largest open area of the PA orifice during the operation of the
valve.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Linear  Area vs. spool
travel
.
One of the following parameters:
Positive spool position open
connections to:
PA and
BT
PA and
PB
PA only
Neutral spool position open
connections to:
PA, PB, AT, and
BT
PA and
AT
PA and
BT
PA and
PB
PA only
Negative spool position open
connections to:
PA, PB, AT, and
BT
PA and
AT
PA and
BT
PA and
PB
PA only
PA orifice spool travel vector
— Vector of spool opening distances relative to fully closed position
[0, .00125, .0025, .00375, .005]
m
(default)  1byn vector
Vector of spool travel distances for the tabular parameterization of
valve area. The vector elements must correspond onetoone with the
elements in the PA orifice area vector parameter.
The values are listed in ascending order and the first element must be
0. Linear interpolation is employed between table data points.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Tabulated data  Area vs. spool
travel
.
One of the following parameters:
Positive spool position open
connections to:
PA and
BT
PA and
PB
PA only
Neutral spool position open
connections to:
PA, PB, AT, and
BT
PA and
AT
PA and
BT
PA and
PB
PA only
Negative spool position open
connections to:
PA, PB, AT, and
BT
PA and
AT
PA and
BT
PA and
PB
PA only
PA orifice area vector
— Vector of valve opening areas
[1e10, 1e05, 4e05, 6e05, .0001]
m^2
(default)  1byn vector
Vector of opening areas for the tabular parameterization of valve
opening area. The vector elements must correspond onetoone with the
elements in the PA spool travel vector parameter.
The elements are listed in ascending order and must be greater than
0.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Tabulated data  Area vs. spool
travel
.
One of the following parameters:
Positive spool position open
connections to:
PA and
BT
PA and
PB
PA only
Neutral spool position open
connections to:
PA, PB, AT, and
BT
PA and
AT
PA and
BT
PA and
PB
PA only
Negative spool position open
connections to:
PA, PB, AT, and
BT
PA and
AT
PA and
BT
PA and
PB
PA only
PA orifice spool travel vector, ds
— Vector of spool opening distances relative to fully closed position
[0, .00125, .0025, .00375, .005]
m
(default)  1byn vector
Vector of spool travel distances for the tabular parameterization of
volumetric flow rates. The spool travel vector forms an independent axis
with the PA orifice pressure drop vector, dp
parameter for the 2D dependent PA orifice volumetric flow
rate table, q(ds,dp) parameter. The values are listed in
ascending order and the first element must be 0. Linear interpolation is
employed between table data points.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Tabulated data  Volumetric flow rate
vs. spool travel and pressure
drop
.
One of the following parameters:
Positive spool position open
connections to:
PA and
BT
PA and
PB
PA only
Neutral spool position open
connections to:
PA, PB, AT, and
BT
PA and
AT
PA and
BT
PA and
PB
PA only
Negative spool position open
connections to:
PA, PB, AT, and
BT
PA and
AT
PA and
BT
PA and
PB
PA only
PA orifice pressure drop vector, dp
— Vector of pressure drop values
[.1, .3, .5, .7] MPa
(default)  1byn vector
Vector of pressure drop values for the tabular parametrization of
volumetric flow rate. The pressure drop vector forms an independent axis
with the PA orifice spool travel vector, ds
parameter for the 2D dependent PA orifice volumetric flow
rate table, q(ds,dp) parameter. The values are listed in
ascending order and must be greater than 0. Linear interpolation is
employed between table data points.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Tabulated data  Volumetric flow rate
vs. spool travel and pressure
drop
.
One of the following parameters:
Positive spool position open
connections to:
PA and
BT
PA and
PB
PA only
Neutral spool position open
connections to:
PA, PB, AT, and
BT
PA and
AT
PA and
BT
PA and
PB
PA only
Negative spool position open
connections to:
PA, PB, AT, and
BT
PA and
AT
PA and
BT
PA and
PB
PA only
PA orifice volumetric flow rate table, q(ds,dp)
— Array of volumetric flow rate values
[1e08, 2.2e08, 2.8e08, 3.4e08; 9e06,
.00015, .0002, .00024; .00036, .00063, .00081, .00096; .00054,
.00094, .0012, .0014; .00091, .0016, .002, .0024]
m^3/s
(default)  MbyN matrix
MbyN matrix of volumetric flow
rates based on independent values of pressure drop and spool travel
distance. M and N are the sizes of
the correlated vectors:
M is the number of vector elements in
the PA orifice pressure drop vector,
dp parameter.
N is the number of vector elements in
the PA orifice spool travel vector,
ds parameter.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Tabulated data  Volumetric flow rate
vs. spool travel and pressure
drop
.
One of the following parameters:
Positive spool position open
connections to:
PA and
BT
PA and
PB
PA only
Neutral spool position open
connections to:
PA, PB, AT, and
BT
PA and
AT
PA and
BT
PA and
PB
PA only
Negative spool position open
connections to:
PA, PB, AT, and
BT
PA and
AT
PA and
BT
PA and
PB
PA only
PA constant orifice area
— Crosssectional area for a constant orifice
1e4 m^2
(default)  positive scalar
Orifice area when the positive, neutral, and negative spool positions
feature the same orifice.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to either:
One the following settings in each parameter:
Positive spool position open
connections to:
PA and
BT
PA and
PB
PA only
Neutral spool position open
connections to:
PA, PB, AT, and
BT
PA and
AT
PA and
BT
PA and
PB
PA only
Negative spool position open
connections to:
PA, PB, AT, and
BT
PA and
AT
PA and
BT
PA and
PB
PA only
PA Constant orifice pressure drop vector
— Vector of pressure differential values for a constant orifice
[.1, .3, .5, .7] MPa
(default)  1byn vector
Vector of pressure differential values over the valve when the
positive, neutral, and negative spool positions feature the same
orifice. The vector elements correspond onetoone with the elements in
the PA Constant orifice volumetric flow rate
vector parameter. The values are listed in ascending
order. Linear interpolation is employed between table data
points.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Tabulated data  Volumetric flow rate
vs. spool travel and pressure
drop
.
One the following settings in each parameter:
Positive spool position open
connections to:
PA and
BT
PA and
PB
PA only
Neutral spool position open
connections to:
PA, PB, AT, and
BT
PA and
AT
PA and
BT
PA and
PB
PA only
Negative spool position open
connections to:
PA, PB, AT, and
BT
PA and
AT
PA and
BT
PA and
PB
PA only
PA Constant orifice volumetric flow rate vector
— Vector of volumetric flow rates for a constant orifice
[.0009, .0016, .002, .0024]
m^3/s
(default)  1byn vector
Vector of pressure differential values over the valve when the
positive, neutral, and negative spool positions feature the same
orifice. The vector elements correspond onetoone with the elements in
the PA Constant orifice pressure drop vector
parameter. The values are listed in ascending order. Linear
interpolation is employed between table data points.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Tabulated data  Volumetric flow rate
vs. spool travel and pressure
drop
.
One the following settings in each parameter:
Positive spool position open
connections to:
PA and
BT
PA and
PB
PA only
Neutral spool position open
connections to:
PA, PB, AT, and
BT
PA and
AT
PA and
BT
PA and
PB
PA only
Negative spool position open
connections to:
PA, PB, AT, and
BT
PA and
AT
PA and
BT
PA and
PB
PA only
PB Orifice
Spool position at maximum PB orifice area
— Spool offset from the neutral position for a fully open PB
orifice
7.5e3 m
(default)  positive scalar
Spool offset from the neutral position for a fully open PB orifice.
The Consistency check for neutral spool position open
connections parameter will notify you if the values set
for this spool position are inconsistent or unphysical according to
other orifice spool positions. To visualize the defined offsets, see
Visualize Orifice Openings.
Dependencies
To enable this parameter, set one of the following parameters:
Positive spool position open connections to:
PB and AT
PA and PB
PB only
Neutral spool position open
connections to:
PA, PB, AT, and
BT
PB and AT
PB and BT
PA and PB
PB only
Negative spool position open
connections to:
PA, PB, AT, and
BT
PB and AT
PB and BT
PA and PB
PB only
Note:
This parameter is enabled only when the PB orifice
settings do not appear in all three spool position
parameters: Positive spool position
open connections, Neutral spool
position open connections, and Negative spool position open
connections.
PB spool travel between closed and open orifice
— Maximum spool stroke
0.005 m
(default)  positive scalar
Maximum distance of spool travel. This value provides an upper limit
to calculations so that simulations do not return unphysical
values.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Linear  Area vs. spool
travel
.
One of the following parameters:
Positive spool position open
connections to:
PB and
AT
PA and
PB
PB only
or set Neutral spool position
open connections to:
PA, PB, AT, and
BT
PB and
AT
PB and
BT
PA and
PB
PB only
or set Negative spool position
open connections to:
PA, PB, AT, and
BT
PB and
AT
PB and
BT
PA and
PB
PB only
PB maximum orifice area
— Maximum orifice opening area
1e4 m^2
(default)  positive scalar
Largest open area of the PB orifice during the operation of the
valve.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Linear  Area vs. spool
travel
.
One the following parameters:
Positive spool position open
connections to:
PB and
AT
PA and
PB
PB only
Neutral spool position open
connections to:
PA, PB, AT, and
BT
PB and
AT
PB and
BT
PA and
PB
PB only
Negative spool position open
connections to:
PA, PB, AT, and
BT
PB and
AT
PB and
BT
PA and
PB
PB only
PB orifice spool travel vector
— Vector of spool opening distances relative to fully closed position
[0, .00125, .0025, .00375, .005]
m
(default)  1byn vector
Vector of spool travel distances for the tabular parameterization of
valve area. The vector elements must correspond onetoone with the
elements in the PB orifice area vector parameter.
The values are listed in ascending order and the first element must be
0. Linear interpolation is employed between table data points.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Tabulated data  Area vs. spool
travel
.
One the following parameters:
Positive spool position open
connections to:
PB and
AT
PA and
PB
PB only
Neutral spool position open
connections to:
PA, PB, AT, and
BT
PB and
AT
PB and
BT
PA and
PB
PB only
Negative spool position open
connections to:
PA, PB, AT, and
BT
PB and
AT
PB and
BT
PA and
PB
PB only
PB orifice area vector
— Vector of valve opening areas
[1e10, 1e05, 4e05, 6e05, .0001]
m^2
(default)  1byn vector
Vector of opening areas for the tabular parameterization of valve
opening area. The vector elements must correspond onetoone with the
elements in the PB spool travel vector parameter.
The elements are listed in ascending order and must be greater than
0.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Tabulated data  Area vs. spool
travel
.
One the following parameters:
Positive spool position open
connections to:
PB and
AT
PA and
PB
PB only
Neutral spool position open
connections to:
PA, PB, AT, and
BT
PB and
AT
PB and
BT
PA and
PB
PB only
Negative spool position open
connections to:
PA, PB, AT, and
BT
PB and
AT
PB and
BT
PA and
PB
PB only
PB orifice spool travel vector, ds
— Vector of spool opening distances relative to fully closed position
[0, .00125, .0025, .00375, .005]
m
(default)  1byn vector
Vector of spool travel distances for the tabular parameterization of
volumetric flow rates. The spool travel vector forms an independent axis
with the PT orifice pressure drop vector, dp
parameter for the 2D dependent PT orifice volumetric flow
rate table, q(ds,dp) parameter. The values are listed in
ascending order and the first element must be 0. Linear interpolation is
employed between table data points.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Tabulated data  Volumetric flow rate
vs. spool travel and pressure
drop
.
One the following parameters:
Positive spool position open
connections to:
PB and
AT
PA and
PB
PB only
Neutral spool position open
connections to:
PA, PB, AT, and
BT
PB and
AT
PB and
BT
PA and
PB
PB only
.
Negative spool position open
connections to:
PA, PB, AT, and
BT
PB and
AT
PB and
BT
PA and
PB
PB only
PB orifice pressure drop vector, dp
— Vector of pressure differential values
[.1, .3, .5, .7] MPa
(default)  1byn vector
Vector of pressure drop values for tabular parametrization of
volumetric flow rate. The pressure drop vector forms an independent axis
with the PB orifice spool travel vector, ds
parameter for the 2D dependent PB orifice volumetric flow
rate table, q(ds,dp) parameter. The values are listed in
ascending order and must be greater than 0. Linear interpolation is
employed between table data points.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Tabulated data  Volumetric flow rate
vs. spool travel and pressure
drop
.
One the following parameters:
Positive spool position open
connections to:
PB and
AT
PA and
PB
PB only
Neutral spool position open
connections to:
PA, PB, AT, and
BT
PB and
AT
PB and
BT
PA and
PB
PB only
Negative spool position open
connections to:
PA, PB, AT, and
BT
PB and
AT
PB and
BT
PA and
PB
PB only
PB orifice volumetric flow rate table, q(ds,dp)
— Array of volumetric flow rate values
[1e08, 2.2e08, 2.8e08, 3.4e08; 9e06,
.00015, .0002, .00024; .00036, .00063, .00081, .00096; .00054,
.00094, .0012, .0014; .00091, .0016, .002, .0024]
m^3/s
(default)  MbyN matrix
MbyN matrix of volumetric flow
rates based on independent values of pressure drop and spool travel
distance. M and N are the sizes of
the correlated vectors:
M is the number of vector elements in
the PB orifice pressure drop vector,
dp parameter.
N is the number of vector elements in
the PB orifice spool travel vector,
ds parameter.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Tabulated data  Volumetric flow rate
vs. spool travel and pressure
drop
.
One the following parameters:
Positive spool position open
connections to:
PB and
AT
PA and
PB
PB only
Neutral spool position open
connections to:
PA, PB, AT, and
BT
PB and
AT
PB and
BT
PA and
PB
PB only
Negative spool position open
connections to:
PA, PB, AT, and
BT
PB and
AT
PB and
BT
PA and
PB
PB only
PB constant orifice area
— Crosssectional area for a constant orifice
1e4 m^2
(default)  positive scalar
Orifice area when the positive, neutral, and negative spool positions
feature the same orifice.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to either:
One the following settings in each parameter:
Positive spool position open
connections to:
PB and
AT
PA and
PB
PB only
Neutral spool position open
connections to:
PA, PB, AT, and
BT
PB and
AT
PB and
BT
PA and
PB
PB only
Negative spool position open
connections to:
PA, PB, AT, and
BT
PB and
AT
PB and
BT
PA and
PB
PB only
PB Constant orifice pressure drop vector
— Vector of pressure differential values for a constant orifice
[.1, .3, .5, .7] MPa
(default)  1byn vector
Vector of pressure differential values over the valve when the
positive, neutral, and negative spool positions feature the same
orifice. The vector elements correspond onetoone with the elements in
the PB Constant orifice volumetric flow rate
vector parameter. The values are listed in ascending
order. Linear interpolation is employed between table data
points.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Tabulated data  Volumetric flow rate
vs. spool travel and pressure
drop
.
One the following settings in each parameter:
Positive spool position open
connections to:
PB and
AT
PA and
PB
PB only
Neutral spool position open
connections to:
PA, PB, AT, and
BT
PB and
AT
PB and
BT
PA and
PB
PB only
Negative spool position open
connections to:
PA, PB, AT, and
BT
PB and
AT
PB and
BT
PA and
PB
PB only
PB Constant orifice volumetric flow rate vector
— Vector of volumetric flow rate values for a constant orifice
[.0009, .0016, .002, .0024]
m^3/s
(default)  1byn vector
Vector of volumetric flow rate values over the valve when the
positive, neutral, and negative spool positions feature the same
orifice. The vector elements correspond onetoone with the elements in
the PB Constant orifice pressure drop vector
parameter. The values are listed in ascending order. Linear
interpolation is employed between table data points.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Tabulated data  Volumetric flow rate
vs. spool travel and pressure
drop
.
One the following settings in each parameter:
Positive spool position open
connections to:
PB and
AT
PA and
PB
PB only
Neutral spool position open
connections to:
PA, PB, AT, and
BT
PB and
AT
PB and
BT
PA and
PB
PB only
Negative spool position open
connections to:
PA, PB, AT, and
BT
PB and
AT
PB and
BT
PA and
PB
PB only
AT Orifice
Spool position at maximum AT orifice area
— Spool offset from the neutral position for a fully open AT
orifice
7.5e3 m
(default)  positive scalar
Spool offset from the neutral position for a fully open AT orifice.
The Consistency check for neutral spool position open
connections parameter will notify you if the values set
for this spool position are inconsistent or unphysical according to
other orifice spool positions. To visualize the defined offsets, see
Visualize Orifice Openings.
Dependencies
To enable this parameter, set one of the following parameters:
Positive spool position open
connections to PB and
AT
.
Neutral spool position open
connections to:
PA, PB, AT, and
BT
PB and
AT
AT and
BT
PA and
AT
AT only
Negative spool position open
connections to PB and
AT
.
Note:
This parameter is enabled only when the AT orifice
settings do not appear in all three spool position
parameters: Positive spool position
open connections, Neutral spool
position open connections, and Negative spool position open
connections.
AT spool travel between closed and open orifice
— Maximum spool stroke
0.005 m
(default)  positive scalar
Maximum distance of spool travel. This value provides an upper limit
to calculations so that simulations do not return unphysical
values.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Linear  Area vs. spool
travel
.
One the following parameters:
Positive spool position open
connections to PB and
AT
Neutral spool position open
connections to:
PA, PB, AT, and
BT
PB and
AT
AT and
BT
PA and
AT
AT only
Negative spool position open
connections to PB and
AT
.
AT maximum orifice area
— Maximum orifice opening area
1e4 m^2
(default)  positive scalar
Largest open area of the AT orifice during the operation of the
valve.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Linear  Area vs. spool
travel
.
One the following parameters:
Positive spool position open
connections to PB and
AT
Neutral spool position open
connections to:
PA, PB, AT, and
BT
PB and
AT
AT and
BT
PA and
AT
AT only
Negative spool position open
connections to PB and
AT
.
AT orifice spool travel vector
— Vector of spool opening distances relative to fully closed position
[0, .00125, .0025, .00375, .005]
m
(default)  1byn vector
Vector of spool travel distances for the tabular parameterization of
valve area. The vector elements must correspond onetoone with the
elements in the AT orifice area vector parameter.
The values are listed in ascending order and the first element must be
0. Linear interpolation is employed between table data points.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Tabulated data  Area vs. spool
travel
.
One the following parameters:
Positive spool position open
connections to PB and
AT
.
Neutral spool position open
connections to:
PA, PB, AT, and
BT
PB and
AT
AT and
BT
PA and
AT
AT only
Negative spool position open
connections to PB and
AT
.
AT orifice area vector
— Vector of valve opening areas
[1e10, 1e05, 4e05, 6e05, .0001]
m^2
(default)  1byn vector
Vector of opening areas for the tabular parameterization of valve
opening area. The vector elements must correspond onetoone with the
elements in the AT spool travel vector parameter.
The elements are listed in ascending order and must be greater than
0.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Tabulated data  Area vs. spool
travel
.
One the following parameters:
Positive spool position open
connections to PB and
AT
.
Neutral spool position open
connections to:
PA, PB, AT, and
BT
PB and
AT
AT and
BT
PA and
AT
AT only
Negative spool position open
connections to PB and
AT
.
AT orifice spool travel vector, ds
— Vector of spool opening distances relative to fully closed position
[0, .00125, .0025, .00375, .005]
m
(default)  1byn vector
Vector of spool travel distances for the tabular parameterization of
volumetric flow rates. The spool travel vector forms an independent axis
with the AT orifice pressure drop vector, dp
parameter for the 2D dependent AT orifice volumetric flow
rate table, q(ds,dp) parameter. The values are listed in
ascending order and the first element must be 0. Linear interpolation is
employed between table data points.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Tabulated data  Volumetric flow rate
vs. spool travel and pressure
drop
.
One the following parameters:
Positive spool position open
connections to PB and
AT
.
Neutral spool position open
connections to:
PA, PB, AT, and
BT
PB and
AT
AT and
BT
PA and
AT
AT only
Negative spool position open
connections to PB and
AT
.
AT orifice pressure drop vector, dp
— Vector of pressure differential values
[.1, .3, .5, .7] MPa
(default)  1byn vector
Vector of pressure drop values for tabular parametrization of
volumetric flow rate. The pressure drop vector forms an independent axis
with the AT orifice spool travel vector, ds
parameter for the 2D dependent AT orifice volumetric flow
rate table, q(ds,dp) parameter. The values are listed in
ascending order and must be greater than 0. Linear interpolation is
employed between table data points.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Tabulated data  Volumetric flow rate
vs. spool travel and pressure
drop
.
One the following parameters:
Positive spool position open
connections to PB and
AT
.
Neutral spool position open
connections to:
PA, PB, AT, and
BT
PB and
AT
AT and
BT
PA and
AT
AT only
Negative spool position open
connections to PB and
AT
.
AT orifice volumetric flow rate table, q(ds,dp)
— Array of volumetric flow rate values
[1e08, 2.2e08, 2.8e08, 3.4e08; 9e06,
.00015, .0002, .00024; .00036, .00063, .00081, .00096; .00054,
.00094, .0012, .0014; .00091, .0016, .002, .0024]
m^3/s
(default)  MbyN matrix
MbyN matrix of volumetric flow
rates based on independent values of pressure drop and spool travel
distance. M and N are the sizes of
the correlated vectors:
M is the number of vector elements in
the AT orifice pressure drop vector,
dp parameter.
N is the number of vector elements in
the AT orifice spool travel vector,
ds parameter.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Tabulated data  Volumetric flow rate
vs. spool travel and pressure
drop
.
One the following parameters:
Positive spool position open
connections to PB and
AT
.
Neutral spool position open
connections to:
PA, PB, AT, and
BT
PB and
AT
AT and
BT
PA and
AT
AT only
Negative spool position open
connections to PB and
AT
.
AT constant orifice area
— Crosssectional area for a constant orifice
1e4 m^2
(default)  positive scalar
Orifice area when the positive, neutral, and negative spool positions
feature the same orifice.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to either:
One the following settings in each parameter:
Positive spool position open
connections to PB and
AT
.
Neutral spool position open
connections to:
PA, PB, AT, and
BT
PB and
AT
AT and
BT
PA and
AT
AT only
Negative spool position open
connections to PB and
AT
.
AT Constant orifice pressure drop vector
— Vector or pressure differential values for a constant orifice
[.1, .3, .5, .7] MPa
(default)  1byn vector
Vector of pressure differential values over the valve when the
positive, neutral, and negative spool positions feature the same
orifice. The vector elements correspond onetoone with the elements in
the AT Constant orifice volumetric flow rate
vector parameter. The values are listed in ascending
order. Linear interpolation is employed between table data
points.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Tabulated data  Volumetric flow rate
vs. spool travel and pressure
drop
.
One the following settings in each parameter:
Positive spool position open
connections to PB and
AT
.
Neutral spool position open
connections to:
PA, PB, AT, and
BT
PB and
AT
AT and
BT
PA and
AT
AT only
Negative spool position open
connections to PB and
AT
.
AT Constant orifice volumetric flow rate vector
— Vector of volumetric flow rate values for a constant orifice
[.0009, .0016, .002, .0024]
m^3/s
(default)  1byn vector
Vector of volumetric flow rate values when the positive, neutral, and
negative spool positions feature the same orifice. The vector elements
correspond onetoone with the elements in the Constant
orifice volumetric flow rate vector parameter. The values
are listed in ascending order. Linear interpolation is employed between
table data points.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Tabulated data  Volumetric flow rate
vs. spool travel and pressure
drop
.
One the following settings in each parameter:
Positive spool position open
connections to PB and
AT
.
Neutral spool position open
connections to:
PA, PB, AT, and
BT
PB and
AT
AT and
BT
PA and
AT
AT only
Negative spool position open
connections to PB and
AT
.
BT Orifice
Spool position at maximum BT orifice area
— Spool offset from the neutral position for a fully open BT
orifice
7.5e3 m
(default)  positive scalar
Spool offset from the neutral position for a fully open BT orifice.
The Consistency check for neutral spool position open
connections parameter will notify you if the values set
for this spool position are inconsistent or unphysical according to
other orifice spool positions. To visualize the defined offsets, see
Visualize Orifice Openings.
Dependencies
To enable this parameter, set one of the following parameters:
Positive spool position open
connections to PB and
BT
.
Neutral spool position open
connections to:
PA, PB, AT, and
BT
AT and
BT
PA and
BT
PB and
BT
BT only
Negative spool position open
connections to PA and
BT
.
Note:
This parameter is enabled only when the BT orifice
settings do not appear in all three spool position
parameters: Positive spool position
open connections, Neutral spool
position open connections, and Negative spool position open
connections.
BT spool travel between closed and open orifice
— Maximum spool stroke
0.005 m
(default)  positive scalar
Maximum distance of spool travel. This value provides an upper limit
to calculations so that simulations do not return unphysical
values.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Linear  Area vs. spool
travel
.
One the following parameters:
Positive spool position open
connections to PB and
BT
.
Neutral spool position open
connections to:
PA, PB, AT, and
BT
AT and
BT
PA and
BT
PB and
BT
BT only
Negative spool position open
connections to PA and
BT
.
BT maximum orifice area
— Maximum orifice opening area
1e4 m^2
(default)  positive scalar
Largest open area of the BT orifice during the operation of the
valve.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Linear  Area vs. spool
travel
.
One the following parameters:
Positive spool position open
connections to PB and
BT
.
Neutral spool position open
connections to:
PA, PB, AT, and
BT
AT and
BT
PA and
BT
PB and
BT
BT only
Negative spool position open
connections to PA and
BT
.
BT orifice spool travel vector
— Vector of spool opening distances relative to fully closed position
[0, .00125, .0025, .00375, .005]
m
(default)  1byn vector
Vector of spool travel distances for the tabular parameterization of
valve area. The vector elements must correspond onetoone with the
elements in the BT orifice area vector parameter.
The values are listed in ascending order and the first element must be
0. Linear interpolation is employed between table data points.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Tabulated data  Area vs. spool
travel
.
One the following parameters:
Positive spool position open
connections to PB and
BT
.
Neutral spool position open
connections to:
PA, PB, AT, and
BT
AT and
BT
PA and
BT
PB and
BT
BT only
Negative spool position open
connections to PA and
BT
.
BT orifice area vector
— Vector of valve opening areas
[1e10, 1e05, 4e05, 6e05, .0001]
m^2
(default)  1byn vector
Vector of opening areas for the tabular parameterization of valve
opening area. The vector elements must correspond onetoone with the
elements in the BT orifice spool travel vector
parameter. The elements are listed in ascending order and must be
greater than 0.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Tabulated data  Area vs. spool
travel
.
One the following parameters:
Positive spool position open
connections to PB and
BT
.
Neutral spool position open
connections to:
PA, PB, AT, and
BT
AT and
BT
PA and
BT
PB and
BT
BT only
Negative spool position open
connections to PA and
BT
.
BT orifice spool travel vector, ds
— Vector of spool opening distances relative to fully closed position
[0, .00125, .0025, .00375, .005]
m
(default)  1byn vector
Vector of control member travel distances for the tabular
parameterization of volumetric flow rates. The spool travel vector forms
an independent axis with the BT orifice pressure drop vector,
dp parameter for the 2D dependent BT orifice
volumetric flow rate table, q(ds,dp) parameter. The
values are listed in ascending order and the first element must be 0.
Linear interpolation is employed between table data points.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Tabulated data  Volumetric flow rate
vs. spool travel and pressure
drop
.
One the following parameters:
Positive spool position open
connections to PB and
BT
.
Neutral spool position open
connections to:
PA, PB, AT, and
BT
AT and
BT
PA and
BT
PB and
BT
BT only
Negative spool position open
connections to PA and
BT
.
BT orifice pressure drop vector, dp
— Vector of pressure differential values
[.1, .3, .5, .7] MPa
(default)  1byn vector
Vector of pressure drop values for tabular parametrization of
volumetric flow rate. The pressure drop vector forms an independent axis
with the BT orifice spool travel vector, ds
parameter for the 2D dependent BT orifice volumetric flow
rate table, q(ds,dp) parameter. The values are listed in
ascending order and must be greater than 0. Linear interpolation is
employed between table data points.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Tabulated data  Volumetric flow rate
vs. spool travel and pressure
drop
.
One the following parameters:
Positive spool position open
connections to PB and
BT
.
Neutral spool position open
connections to:
PA, PB, AT, and
BT
AT and
BT
PA and
BT
PB and
BT
BT only
Negative spool position open
connections to PA and
BT
.
BT orifice volumetric flow rate table, q(ds,dp)
— Array of volumetric flow rate values
[1e08, 2.2e08, 2.8e08, 3.4e08; 9e06,
.00015, .0002, .00024; .00036, .00063, .00081, .00096; .00054,
.00094, .0012, .0014; .00091, .0016, .002, .0024]
m^3/s
(default)  MbyN matrix
MbyN matrix of volumetric flow
rates based on independent values of pressure drop and spool travel
distance. M and N are the sizes of
the correlated vectors:
M is the number of vector elements in
the BT orifice pressure drop vector,
dp parameter.
N is the number of vector elements in
the BT orifice spool travel vector,
ds parameter.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Tabulated data  Volumetric flow rate
vs. spool travel and pressure
drop
.
One the following parameters:
Positive spool position open
connections to PB and
BT
.
Neutral spool position open
connections to:
PA, PB, AT, and
BT
AT and
BT
PA and
BT
PB and
BT
BT only
Negative spool position open
connections to PA and
BT
.
BT constant orifice area
— Crosssectional orifice area for constant orifices
1e4 m^2
(default)  positive scalar
Orifice area when the positive, neutral, and negative spool positions
feature the same orifice.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
either:
One of the settings in each parameter:
Positive spool position open
connections to PB and
BT
.
Neutral spool position open
connections to:
PA, PB, AT, and
BT
AT and
BT
PA and
BT
PB and
BT
BT only
Negative spool position open
connections to PA and
BT
.
BT Constant orifice pressure drop vector
— Vector of pressure differential values for a constant orifice
[.1, .3, .5, .7] MPa
(default)  1byn vector
Vector of pressure differential values over the valve when the
positive, neutral, and negative spool positions feature the same
orifice. The vector elements correspond onetoone with the elements in
the BT Constant orifice volumetric flow rate
vector parameter. The values are listed in ascending
order. Linear interpolation is employed between table data
points.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Tabulated data  Volumetric flow rate
vs. spool travel and pressure
drop
.
One the settings in each parameter:
Positive spool position open
connections to PB and
BT
.
Neutral spool position open
connections to:
PA, PB, AT, and
BT
AT and
BT
PA and
BT
PB and
BT
BT only
Negative spool position open
connections to PA and
BT
.
BT Constant orifice volumetric flow rate vector
— Vector of volumetric flow rates for a constant orifice
[.0009, .0016, .002, .0024]
m^3/s
(default)  1byn vector
Vector of pressure differential values over the valve when the
positive, neutral, and negative spool positions feature the same
orifice. The vector elements correspond onetoone with the elements in
the BT Constant orifice pressure drop vector
parameter. The values are listed in ascending order. Linear
interpolation is employed between table data points.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Tabulated data  Volumetric flow rate
vs. spool travel and pressure
drop
.
One the settings in each parameter:
Positive spool position open
connections to PB and
BT
.
Neutral spool position open
connections to:
PA, PB, AT, and
BT
AT and
BT
PA and
BT
PB and
BT
BT only
Negative spool position open
connections to PA and
BT
.
PT Orifice
Spool position at maximum PT orifice area
— Spool offset from the neutral position for a fully open PT
orifice
0 m
(default)  positive scalar
Spool offset from the neutral position for a fully open PT orifice.
The Consistency check for neutral spool position open
connections parameter will notify you if the values set
for this spool position are inconsistent or unphysical according to
other orifice spool positions. To visualize the defined offsets, see
Visualize Orifice Openings.
Dependencies
To enable this parameter, set Neutral spool position
open connections to PT
only
.
PT spool travel between closed and open orifice
— Maximum spool stroke
0.005 m
(default)  positive scalar
Maximum distance of spool travel. This value provides an upper limit
to calculations so that simulations do not return unphysical
values.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Linear  Area vs. spool
travel
.
Neutral spool position open
connections to PT
only
.
PT maximum orifice area
— Maximum orifice opening area
1e4 m^2
(default)  positive scalar
Largest open area of the PT orifice during the operation of the
valve.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Linear  Area vs. spool
travel
.
Neutral spool position open
connections to PT
only
.
PT orifice spool travel vector
— Vector of spool opening distances relative to fully closed position
[0, .00125, .0025, .00375, .005]
m
(default)  1byn vector
Vector of control member travel distances for the tabular
parameterization of valve area. The vector elements must correspond
onetoone with the elements in the PT orifice area
vector parameter. The values are listed in ascending
order and the first element must be 0. Linear interpolation is employed
between table data points.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Tabulated data  Area vs. spool
travel
.
Neutral spool position open
connections to PT
only
.
PT orifice spool travel vector, ds
— Vector of spool opening distances relative to fullyclosed position
[0, .00125, .0025, .00375, .005]
m
(default)  1byn vector
Vector of control member travel distances for the tabular
parameterization of volumetric flow rate. The spool travel vector forms
an independent axis with the PT orifice pressure drop vector,
dp parameter for the 2D dependent PT orifice
volumetric flow rate table, q(ds,dp) parameter. The
values are listed in ascending order and the first element must be 0.
Linear interpolation is employed between table data points.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Tabulated data  Area vs. spool
travel
.
Neutral spool position open
connections to PT
only
.
PT orifice pressure drop vector, dp
— Vector of pressure differential values
[.1, .3, .5, .7] MPa
(default)  1byn vector
Vector of pressure drop values for tabular parametrization of
volumetric flow rate. The pressure drop vector forms an independent axis
with the PT orifice spool travel vector, ds
parameter for the 2D dependent PT orifice volumetric flow
rate table, q(ds,dp) parameter. The values are listed in
ascending order and must be greater than 0. Linear interpolation is
employed between table data points.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Tabulated data  Area vs. spool
travel
.
Neutral spool position open
connections to PT
only
.
PT orifice volumetric flow rate table, q(ds,dp)
— Array of volumetric flow rates
[1e08, 2.2e08, 2.8e08, 3.4e08; 9e06,
.00015, .0002, .00024; .00036, .00063, .00081, .00096; .00054,
.00094, .0012, .0014; .00091, .0016, .002, .0024]
m^3/s
(default)  MbyN matrix
MbyN matrix of volumetric flow
rates based on independent values of pressure drop and spool travel
distance. M and N are the sizes of
the correlated vectors:
M is the number of vector elements in
the PT orifice pressure drop vector,
dp parameter.
N is the number of vector elements in
the PT orifice spool travel vector,
ds parameter.
Dependencies
To enable this parameter, set:
Area characteristics to
Different for each flow
path
.
Orifice parameterization to
Tabulated data  Area vs. spool
travel
.
Neutral spool position open
connections to PT
only
.
Introduced in R2020a