Check Valve 2
Check valve with continuous variable
Description
Equations
Variables
Connections
Parameters
The Check Valve 2 (or Check Valve II) component allows fluid flow in one direction, from port A to port B.
This model uses a continuous-variable to model the change from open to closed. In the open-state the valve has a resistance given by Ropen. In the closed-state the valve has a conductance given by Gclose.
Optional Volumes
The boolean parameters Use volume A and Use volume B, when true, add optional volumes VA and VB to ports A and B, respectively. See Port Volumes for details.
If two orifices or valves are connected, enabling a volume at the common port reduces the stiffness of the system and improves the solvability.
closed=s<0
p=pA−pB={sGclosedclosedsotherwiseq=qA−qVA={sclosedsRopenotherwise
VfA={VA1+pAEluseVolumeA0otherwiseVfB={VB1+pBEluseVolumeB0otherwise
qVA={dVfAdtuseVolumeA0otherwiseqVB={dVfBdtuseVolumeB0otherwise
qA+qB−qVA−qVB=0
qsummary=qflowScaleSummarydpsummary=ppressScaleSummary
Name
Units
Modelica ID
p
Pa
Pressure drop from A to B
q
m3s
Flow rate from port A to port B
qsummary
Internal flow sensor
q_summary
dpsummary
Internal pressure difference sensor
dp_summary
Vfx
m3
Effective volume at port x,x∈A,B
qVx
Flow rate into effective volume at port x,x∈A,B
portA
Upstream hydraulic port
portB
Downstream hydraulic port
General Parameters
Default
Ropen
1·10−5
Pasm3
Open check valve resistance
Gclosed
m3Pas
Closed check valve conductance
Start closed
true
True initializes valve to closed, false to open
Startclosed
useVolumeA
false
True (checked) means a hydraulic volume chamber is added to portA
VA
1·10−6
Volume of chamber A
Va
useVolumeB
True (checked) means a hydraulic volume chamber is added to portB
VB
Volume of chamber B
Vb
For more information see Port Volumes.
Fluid Parameters
The following parameters, used in the equations, are properties of the Hydraulic System Properties component used in the model.
ν
m2s
Kinematic viscosity of fluid
nu
ρ
kgm3
Density of fluid
rho
El
Bulk modulus of fluid
See Also
Hydraulics Library
Valves
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