Non Return Valve with Pressure Dependency - MapleSim Help

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Non Return Valve with Pressure Dependency

Non return valve with table-based pressure-dependency

Description

The Non Return Valve with Pressure Dependency component models a check Valve where the opening varies with the pressure across the device.

The Conductance and critical pressure ratio are computed as a function of the pressure difference between port A and port B from a data table containing values of pressure difference vs. the corresponding C and b. Based on C and b, the pressure vs. flow rate relationships are derived by the formulation used in the Orifice ISO 6358 component.

 Formulation Approaches Two approaches were taken for formulation of the flow equation inside the device. When the boolean parameter $\mathrm{UseRestrictionArea}$ is true, the sonic conductance is calculated from the restriction area using Gidlund's approximation.
 Pressure vs. Conductance and b For this component, the Conductance and Critical pressure ratio of the orifice must be specified as a function of the pressure difference in the form of a table. The following parameters allows users to specify the necessary data for this calculation. Data Source: This parameter allows users to specify the nature of the source file for the Pressure vs. C and b table. The available options are file, attachment, and inline. file: Use this option to specify a source file (an Excel or a CSV file) located on the hard drive. Use the $\left\{C,B\right\}\left(\mathrm{dP}\right)$ parameter to browse to and/or select the data file. The data file will not be attached to the MapleSim model. attachment: Use this option to specify a data file (an Excel or a CSV file) that is attached to the MapleSim model. To be used as an attachment, data files must be attached to the MapleSim model and be categorized under Data Sets. The attached files in a MapleSim model can be viewed in the Attachments pane under the Data Sets section. For more information, see Attaching a File to a Model. If the required file is not already attached to the MapleSim model, use the $\left\{C,b\right\}\left(\mathrm{dP}\right)$ parameter to attach a new file. Note: If the file option is used, subsequent changes to the source file will be incorporated into MapleSim simulations. 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 incorporated in the simulation, the file must be reattached. The Data Generation App can be used to generate table data from mathematical functions using Maple code. For more information about MapleSim apps, see Using MapleSim Apps. inline: Use this option to directly specify the pressure vs. area relationship in the form of a table. In the $\left\{C,b\right\}\left(\mathrm{dP}\right)$ parameter, enter an $m×3$ matrix. The first column must contain values of pressure difference and the second column must contain corresponding values of the Conductance and third column must contain the critical pressure ratio b. Note: To change the dimensions of 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 or rows and columns and then click OK. Skip rows: This option allows users to specify the number of top rows to be ignored during the calculations. This option can be useful when the Excel file contains header information. Smoothness: The smoothness option specifies how the data table is interpolated. Pressure difference unit: This option specifies the unit of pressure used in the supplied data.
 Equations if UseRestrictionArea = true When UseRestrictionArea is checked, Gidlund's approximation is used to calculate C using Ar $p={p}_{A}-{p}_{B}\phantom{\rule[-0.0ex]{0.0em}{0.0ex}}\phantom{\rule[-0.0ex]{0.0em}{0.0ex}}$ Orifice Gas Equations Linear Gain k is given by

Variables

 Name Units Description Modelica ID $p$ $\mathrm{Pa}$ Pressure drop from A to B p ${p}_{X}$ $\mathrm{Pa}$ Pressure at port X pX $\mathrm{mflow}$ $\frac{\mathrm{kg}}{s}$ Flow rate from A to B mflow ${\mathrm{hflow}}_{X}$ $\frac{\mathrm{kJ}}{\mathrm{kg}}$ Specific Enthalpy into port X hflowX

Connections

 Name Description Modelica ID $\mathrm{portA}$ Upstream Pneumatic port portA $\mathrm{portB}$ Downstream Pneumatic port portB

Parameters

Fluid Medium Parameters

The Gas parameters used in the equations are properties defined in the Gas Model component used in the model.

 Name Default Units Description $\mathrm{true}$  When true the default gas properties defined for Air will be used. $\mathrm{medium}$ $-$  When Use default medium is false this option gets turned on. The user can specify the name of the Gas model dragged into the canvas.

Orifice Parameter

 Name Default Units Description Modelica ID $\mathrm{UseRestrictionArea}$ $\mathrm{false}$ True (checked) means sonic conductance is calculated from restriction area using Gidlund's approximation UseRestrictionArea $\mathrm{b__lamreg}$ $0.999$ Flow transition from turbulent to laminar b_lamreg

Orifice Data vs. Pressure

 Name Default Description Modelica ID Data source inline Data source datasourcemode $\left\{C,b\right\}\left(\mathrm{dP}\right)$ [1] Data set table $A$ [2] Data set table Skip rows $0$ Number of rows to skip skipRows Smoothnes Linear Smoothness of table interpolation smoothness Pressure difference unit $\mathrm{kPa}$ Unit of pressure used in the data pressUnit

[1]

[2]