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MapleSim Hydraulics Library from Modelon

Check Valve Two  Spring-loaded check valve with laminar/turbulent flow

The Check Valve Two component describes a spring-loaded check valve with laminar/turbulent flow. The resistance depends on the pressure differential, Δp=pApB:

&Delta;p<popen

Leakage from high pressure port to low pressure port only. q&equals;&Delta;pGleak

popen<&Delta;p

Valve is wide open. Flow mode depends on Reynolds number. Resistance modeled as an orifice in parallel with laminar resistance.

 

In some cases it is either necessary or helpful to include the dynamics of a check valve: the poppet needs some time to close or open the flow path. This effect is modeled by a first order system. The parameter tau_ball (found in the General section under the Inspector tab) gives the time to open or close the valve 95%.

The mass and flow forces are not included. Use the modifier(s)

VolumeA(port_A(p(start=1e5,fixed=true)))

and/or

VolumeB(port_A(p(start=1e5,fixed=true)))

to set the initial condition(s) for the pressure of the lumped volume(s) Pa.

Related Components

Name

Description

Check Valve

Spring-loaded check valve with laminar/turbulent flow (different characteristic)

Check Valve Two No States

Ideal spring-loaded check valve with laminar/turbulent flow, additional information

Connections

Name

Description

Modelica ID

portA

Layout of port where oil flows into an element (0<mflow, pB<pA means 0<&Delta;p)

port_A

portB

Hydraulic port where oil leaves the component (mflow<0, pB<pA means 0<&Delta;p)

port_B

oil

 

oil

Parameters

General Parameters

Name

Default

Units

Description

Modelica ID

&Delta;Tsystem

0

K

Temperature offset from system temperature

dT_system

use volume A

true

 

If true, a volume is present at port_A

useVolumeA

use volume B

true

 

If true, a volume is present at port_B

useVolumeB

VA

10-6

m3

Geometric volume at port A

volumeA

VB

10-6

m3

Geometric volume at port B

volumeB

d

0.001

m

Diameter of equivalent orifice

diameter

area

0.001

m2

Area of the equivalent orifice

area

k1

10

 

Laminar part of orifice model

k1

k2

2

 

Turbulent part of orifice model, k2&equals;1Cd2

k2

Cd

0.707

 

Max discharge coefficient

C_d

λc

2k1k2

 

Critical flow number

lambdac

Gleak

10-12

m3sPa

Conductance of leakage

GLeak

pnom

106

Pa

Nominal pressure drop

pnom

qnom

1.89·10-5

m3s

Nominal volume flow rate

qnom

ρnom

865

kgm3

Nominal density

rhonom

popen

1.25·105

Pa

Transition pressure

popen

orif

1

 

Orifice dimension

orif

Transition

1

 

Transition model

Transition

τball

0

s

Time to open or close check valve 95 %

tau_ball

See Also

Check Valve, Check Valve Two No States, Valves, MapleSim Hydraulics Library from Modelon Overview


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