Spool Force - MapleSim Help

Online Help

All Products    Maple    MapleSim


Home : Support : Online Help : MapleSim : MapleSim Component Library : Hydraulics : Valve Forces : componentLibrary/hydraulics/valves/valveForces/SpoolForce

Spool Force

Component with two horizontal hydraulic connections

 

Description

Equations

Variables

Connections

Parameters

Description

The Spool Force component models an axial hydraulic back-force exerted on the spool by the hydraulic fluid flowing through the valve.

This component must be connected in series with the spool valve in the circuit where the pressure-flow characteristic is based on the equations of the Orifice component.

Variation

The Variation parameter selects one of two options that determine how k, a coefficient for the spool force, is computed from a look-up table:

1. The table specifies the jet angle θ as a function of the displacement; k is the cosine of the jet angle.

2. The table specifies k directly as a function of displacement.

The Force Direction parameter specifies the direction of force applied to the spool.

Equations

{{θ=MapleSim.Interpolate1Ddataθ,displacement,2,Smoothnessk=cosθconvertedθconverted=π180θ}variation=1k=MapleSim.Interpolate1Ddatak,displacement,2,Smoothnessvariation=2

p=pApBq=qA=qB

A=maxArea,Amin

F=ρq2AkorientFdir

Fdir={1Force Direction=1−1Force Direction=2

orient={10q−1otherwise

displacement={1000xdispUnit1=1xotherwise

Variables

Name

Units

Description

Modelica ID

p

Pa

Pressure drop from A to B

p

q

m3s

Flow rate into port A

q

displacement

mm

Valve displacement

displacement

θ

degree

Jet angle in degrees

theta

θconverted

radian

Jet angle in radians

theta_converted

Connections

Name

Description

Modelica ID

portA

Hydraulic port on left side

portA

portB

Hydraulic port on right side

portB

Area

Signal input; orifice cross-section in mm2

Area

x

Signal input; valve displacement in m

x

Parameters

Data Parameters

Name

Default

Units

Description

Modelica ID

Variation

1

 

Data source variation

paramType

Data source

inline

 

Data source for jet angle as a function of displacement

datasourcemode1

θx

 

 

First column: displacement, second column: jet angle

table_theta

dataθ

 

 

 

data_theta

Force direction

1

 

Direction of spool force

paramType2

Data source

inline

 

Data source for k as a function of displacement

datasourcemode2

kx

 

 

First column: displacement, second column: discharge coefficient

table_k

datak

 

 

 

data_k

Smoothness

linear

 

Smoothness of table interpolation for all the data

Smoothness

θunit

1

degree

Unit of jet angle used in the data table

dispUnit1

Displacement unit

1

mm

Unit of displacement used in the data table

dispUnit2

Fluid Parameters

The following parameters, used in the equations, are properties of the Hydraulic Fluid component used in the model.

Name

Units

Description

Modelica ID

ν

m2s

Kinematic viscosity of fluid

nu

ρ

kgm3

Density of fluid

rho

El

Pa

Bulk modulus of fluid

El

See Also

Hydraulics Library

Valve Forces