FixedDisplacementPump

Partial Pump

    FixedDisplacementPump

Library

HydraulicsByFluidon/Components/Pumps

Description

Model of a pump with fixed displacement volume and losses.

The main parameters of the pump are its maximum Displacement volume and the Rotational moment of inertia.

The losses are parameterised by providing volumetric and mechanical efficiencies Volumetric efficiency and Mechanical efficiency for a given operating point. The operating point is characterised by a reference pressure difference Reference pressure difference and a corresponding shaft speed Reference speed. Based on the entered values, the parameters of a laminar throttle (volumetric losses) and a linear damper (representing the mechanical losses) are determined automatically. Unlike the efficiencies, the parameters of these two elements typically do not vary significantly with the operating conditions.

The parameter Ratio external Leakage / total Leakage allows to split the leakage between internal and external leakage. A gear pump e. g. typically has no external leakage, Ratio external Leakage / total Leakage has to be set to 0. In contrast, a piston pump has a significant external leakage (0.5 < Ratio external Leakage / total Leakage <= 1).

minSuctionPressure takes into account that a pump requires a minimaum suction pressure for full flow. Below this pressure, the flow rate is reduced. In this model, the reduction is assumed to be simplified as a linear function of suction pressure in relation to minSuctionPressure.

Parameters

FixedDisplacementPump_0

NameLabelDescriptionData TypeValid Values

mo_dispVolume

dispVolume

Displacement volume

Scalar

mo_minSuctionPressure

minSuctionPressure

Pressure limit at suction port below which flow is reduced

Scalar

mo_Jrot

Jrot

Rotational moment of inertia

Scalar

mo_deadVolume

deadVolume

Dead volume at ports

Scalar

mo_nominalVolumeFlow

nominalVolumeFlow

Scalar

mo_volumeFlowLoss

volumeFlowLoss

Scalar

mo_dvisc

dvisc

Scalar

mo_etaVol

etaVol

Volumetric efficiency @ nRef, dpRef

Scalar

mo_leakageReferenceDensity

leakageReferenceDensity

Reference density for volumetric efficiency

Scalar

mo_ratioLeakageExtern

ratioLeakageExtern

Ratio external Leakage / total Leakage

Scalar

mo_useLeakagePort

useLeakagePort

Enable leakage port, otherwise implicitly connected with tank

Number

0
1

mo_etaHm

etaHm

Mechanical efficiency @ nRef, dpRef

Scalar

mo_nRef

nRef

Reference speed (1/min)

Scalar

mo_dpRef

dpRef

Reference pressure difference

Scalar

mo_pA

pA

pA

Structure

mo_pA/fixed

fixed

Cell of scalars

true
false

mo_pA/start

start

Cell of scalars

mo_pB

pB

pB

Structure

mo_pB/fixed

fixed

Cell of scalars

true
false

mo_pB/start

start

Cell of scalars

FixedDisplacementPump_1

NameLabelDescriptionData TypeValid Values

mo_stateSelect

stateSelect

Priority to use phi and w as states

Structure

mo_stateSelect/choice1

StateSelect.never

Number

0
1

mo_stateSelect/choice2

StateSelect.avoid

Number

0
1

mo_stateSelect/choice3

StateSelect.default

Number

0
1

mo_stateSelect/choice4

StateSelect.prefer

Number

0
1

mo_stateSelect/choice5

StateSelect.always

Number

0
1

FixedDisplacementPump_2

NameLabelDescriptionData TypeValid Values

mo_forwardFluidProperties

forwardFluidProperties

Forward fluid properties between ports

Scalar

true
false

FixedDisplacementPump_3

NameLabelDescriptionData TypeValid Values

mo__nmodifiers

Number of Modifiers

Specifies the number of modifiers

Number

mo__modifiers

Modifiers

Add new modifier

Structure

mo__modifiers/varname

Variable name

Cell of strings

'volumeFlowA'
'volumeFlowB'
'fluidId'
'phi'
'w'

mo__modifiers/attribute

Attribute

Cell of strings

'start'
'fixed'

mo__modifiers/value

Value

Ports

NameTypeDescriptionIO TypeNumber

fluidPortA

implicit

Hydraulic port A

input

1

fluidPortB

implicit

Hydraulic port B

input

2

flange_a

implicit

input

3

flange_b

implicit

output

1

Port 5

implicit

Hydraulic port Leakage

input

mo_useLeakagePort

See Also