ShuttleValve-States

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ShuttleValve-States

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Iconic Diagrams\Hydraulics\Valves

Use

Domains: Continuous. Size: 1-D. Kind: Iconic Diagrams (Hydraulics).

Description - Default

This model describes a loop shuttle valve with lumped volumes. A shuttle valve is a type of valve which allows fluid to flow through it from one of two sources. Shuttle valves accept flow from two different sources (pa) and (pb) and divert the highest pressure to a single outlet port (p_out). Shuttle valves are commonly used in Load Sensing circuits and at a cylinder to measure the working pressure, as well as Brake circuits. Normal shuttle valve are mostly ball and poppet types valves.

ShuttleValve-States

The default implementation of the shuttle valve assumes ideal behaviour:

 

p.out.p = maximum(pa.p, pb.p)

pa.phi = pb.phi = 0;

 

This model sets the flows of the input ports to zero and assumes the output flow is zero as well. However the output flow is determined by the component that is connected with the output port. A warning is given when the output flow exceeds 1.0e-5 m3. If flows are important in your model, use the Spool Dynamics implementation of this model (see below).

Interface - Default

Ports

Description

pa, pb

p_out

Input terminals of the valve.

Output terminal.

Causality

 

preferred pressure out pa

preferred pressure out pb

preferred pressure out p_out

 

Description - BallDynamics

This model describes a loop shuttle valve with lumped volumes. This implementation is equal to the default implementation but with modeled dynamics. A small pressure difference between the inlet ports pa and pb is enough to make the ball switch from one side to the other. This pressure is called the overlap pressure po.

 

ShuttleValveDiagram

Interface - BallDynamics

Ports

Description

pa, pb

p_out

Input terminals of the valve.

Output terminal.

Causality

 

preferred pressure out pa

preferred pressure out pb

preferred pressure out p_out

 

Parameters

 

rho

GLeak

Amax

Cd

f

d

p_o

Mass density of the fluid [kg/m3].

Conductance of the laminar leakage flows [m3/s.Pa], GLeak >= 0.

Maximum valve areas when the valves are open [m2], Amax > 0.

Discharge coefficient [], Cd > 0.

Bandwidth of the valve dynamics [Hz], f > 0.

Damping of the valve dynamics [], d > 0

Overlap pressure [Pa].