DCV 42 Generic
4-way 2-position valve with user-specified flow paths
Description
Spool Signal vs. Sonic Conductance
Connections
Parameters
The DCV 42 Generic component is a four-port, two-position valve. Typically, port 1 is connected to the pressure line, port 2 and port 4 are the outlet ports, and port 3 is the exhaust port. This valve allows flow between the ports based on the user-specified custom data.
There are six paths (1-2, 1-4, 2-3, 3-4, 2-4, and 1-3) interconnected to each other with varying sonic conductance according to the spool signal, thereby allowing fluid to flow between the different ports. The spool signal value can range from 0 to 1. The critical pressure ratio is assumed to be constant for each path.
Based on the path sonic conductance and critical pressure ratio, the pressure vs. mass flow rate relationship is calculated by the formulation used in the Orifice ISO 6358 component.
This valve allows the user to specify the custom scenario according to the need. The user can choose between either of the two options specified below.
1. Characteristic Curve - Enable the Characteristic curves check box to use this option. By choosing this option, user-supplied characteristic data defines the relationship between the spool signal and the sonic conductance for each path. A suboption is that the sonic conductance can either be given as a final value or as a scaled value by toggling Use scales options.
2. Piecewise Linear - Disable the Characteristic curves check box to use this option. Sonic conductance value for each path will change according to the spool signal based on a piecewise linear function, with the transition length set by the band parameter. Using this option, sonic conductance values for two extremes of spool signal, s, should be specified for each path as a vector with two entries. The first and the second entries are for when s=0 and s=1, respectively. A suboption under this category is that the sonic conductance can either be given as a final value or as a scaled value by toggling Use scales option.
For the characteristic curve option, the final sonic conductance value or the scaled value are specified as a function of the spool signal using a table. The seven columns in this table correspond to (signal, 1-2, 1-4, 2-3, 3-4, 2-4, 1-3) order. The spool signal value can range from 0 to 1.
The following parameters allow users to specify the necessary data for this calculation.
Data Source: This parameter allows users to specify the type of the source file. The available options are file, inline, and attachment.
- file: Use this option to specify a source file (an Excel or a CSV file) located on the hard drive. Use the data__S or the data__C field to browse your directory and select the source file.
Note: If the file option is used, subsequent changes to the source file will be reflected in MapleSim simulations.
- inline: Use MapleSim GUI to insert the data points for the table.
Note: To change the dimensions of the table, right-click (Control-click for Mac®) the parameter field and select Edit Matrix Dimensions. In the Matrix Dimensions dialog, enter values for the number of rows and columns and then click OK.
- attachment: Use this option to specify a data file (an Excel or a CSV file) that is attached to the MapleSim model. Use the the data__S or the data__C field to select an attached file or to browse your directory and attach a new data file. The attached files in a MapleSim model can be viewed in the Attachments tab under the Data Sets section. For more information, see Attaching a File to a Model.
Note: If the attachment option is used, subsequent changes to the source file will not affect the version attached to the MapleSim model. To ensure updates to the source files are reflected in simulations, the file must be reattached.
Smoothness: The smoothness option specifies how the data table is interpolated.
Name
Modelica ID
port1
Pneumatic port 1 (pressure)
port2
Pneumatic port 2 (outlet)
port3
Pneumatic port 3 (exhaust)
port4
Pneumatic port 4 (outlet)
s
Spool input signal
Sonic Conductance
Condition
Default
Units
Characteristic curves
-
false
When checked (true), sonic conductance data can be loaded from a file, written inline, or loaded from an attachment. Otherwise, data are individually defined inline
CharacteristicCurves
band
Characteristic curves = false
0.1
Transition length in normalized spool displacement, ranging between 0.1 and 0.9
Use scales
true
When checked (true), various maximum conductance values are the product of Cmax and the scaling coefficients
useScales
C__max
Use scales = true
1⋅10−8
m3s⋅Pa
Sonic conductance when the path is fully open
C_max
sX-Y
and
Scaling coefficients, see [1]
s_XY
CX-Y
Sonic conductance values, see [2]
C_XY
data source
Characteristic curves = true
inline
Data mode for spool position vs. sonic conductance for each path
datasourcemode
S
data source = inline
use scales = true
Defines data points for spool signal vs. scaling coefficients for sonic condcutance of different paths: Columns 1 to 7 are: spool signal, 1-2, 1-4, 2-3, 3-4, 2-4, 1-3
C
use scales = false
Defines data points for spool signal vs. sonic condcutance values of different paths: Columns 1 to 7 are: spool signal, 1-2, 1-4, 2-3, 3-4, 2-4, 1-3
data__S
data source = not inline
Data set that defines data points for spool signal vs. scaling coefficients for sonic conductance of different paths: Columns 1 to 7 are: spool signal, 1-2, 1-4, 2-3, 3-4, 2-4, 1-3
data_S
data__C
Data set that defines data points for spool signal vs. sonic conductance values of different paths: Columns 1 to 7 are: spool signal, 1-2, 1-4, 2-3, 3-4, 2-4, 1-3
data_C
Smoothness
The smoothness of table interpolation
Smoothenss
[1] sX-Y is a two-element vector that specifies the scaling coefficient between ports X and Y when the s input is 0 and 1, respectively. The sonic conductance value is computed using Cmax, spool signal (s), and scaling coefficients, sX−Y.
[2] CX-Y is a two-element vector that specifies the area between ports X and Y when the s input is 0 and 1, respectively.
Critical Pressure Ratio
b
Critical pressure ratio for 1-2, 1-4, 2-3, 3-4, 2-4, and 1-3 paths, respectively
See Also
Directional Control Valves
Pneumatics Library
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