VariableDisplacementPump
Partial Pump
Library
Components/Pumps
Description
Model of a pump with variable displacement volume and losses.
The main parameters of the pump are its maximum Displacement volume and the Rotational moment of inertia. The displacement volume can be adjusted by using the setpoint signal:
| setpoint = 0 | displacement volume = 0 |
| setpoint > 1 | displacement volume = dispVolume sign(w) = sign(fluidPortA.mFlow) |
| setpoint < -1 | displacement volume = dispVolume sign(w) = -sign(fluidPortA.mFlow) |
| 1 > setpoint > 0 | displacement volume = dispVolume * setpoint sign(w) = sign(fluidPortA.mFlow) |
| -1 < setpoint < 0 | displacement volume = dispVolume * setpoint sign(w) = -sign(fluidPortA.mFlow) |
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 Ration external Leakage / total Leakage allows to split the leakage between internal and external leakage. A gear pump e. g. typically has no external leakage, Ration external Leakage / total Leakage has to be set to 0. In contrast, a piston pump has a significant external leakage (0.5 < Ration external Leakage / total Leakage <= 1).
Parameters
| Name | Label | Description | Data Type | Valid Values |
|---|---|---|---|---|
mo_dispVolume | dispVolume | Displacement volume | Scalar | |
mo_Jrot | Jrot | Rotational moment of inertia | Scalar | |
mo_deadVolume | deadVolume | Dead volume at ports | 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 |
mo_etaHm | etaHm | Mechanical efficiency @ nRef, dpRef | Scalar | |
mo_nRef | nRef | Reference speed (1/min) | Scalar | |
mo_dpRef | dpRef | Reference pressure difference | Scalar | |
mo_nominalVolumeFlow | nominalVolumeFlow | Scalar | ||
mo_volumeFlowLoss | volumeFlowLoss | Scalar | ||
mo_dvisc | dvisc | Scalar |
| Name | Label | Description | Data Type | Valid Values |
|---|---|---|---|---|
mo_stateSelect | stateSelect | Priority to use phi and w as states | Structure | |
mo_stateSelect/choice1 | StateSelect.never | Number | 0 | |
mo_stateSelect/choice2 | StateSelect.avoid | Number | 0 | |
mo_stateSelect/choice3 | StateSelect.default | Number | 0 | |
mo_stateSelect/choice4 | StateSelect.prefer | Number | 0 | |
mo_stateSelect/choice5 | StateSelect.always | Number | 0 |
| Name | Label | Description | Data Type | Valid Values |
|---|---|---|---|---|
mo_forwardFluidProperties | forwardFluidProperties | Forward fluid properties between ports | Scalar | true |
| Name | Label | Description | Data Type | Valid Values |
|---|---|---|---|---|
mo_volumeFlowA | volumeFlowA | volumeFlowA | Structure | |
mo_volumeFlowA/fixed | fixed | Cell of scalars | true | |
mo_volumeFlowA/start | start | Cell of scalars | ||
mo_volumeFlowB | volumeFlowB | volumeFlowB | Structure | |
mo_volumeFlowB/fixed | fixed | Cell of scalars | true | |
mo_volumeFlowB/start | start | Cell of scalars | ||
mo_pA | pA | pA | Structure | |
mo_pA/fixed | fixed | Cell of scalars | true | |
mo_pA/start | start | Cell of scalars | ||
mo_pB | pB | pB | Structure | |
mo_pB/fixed | fixed | Cell of scalars | true | |
mo_pB/start | start | Cell of scalars | ||
mo_phi | phi | phi | Structure | |
mo_phi/fixed | fixed | Cell of scalars | true | |
mo_phi/start | start | Cell of scalars | ||
mo_w | w | w | Structure | |
mo_w/fixed | fixed | Cell of scalars | true | |
mo_w/start | start | Cell of scalars | ||
mo_setpoint | setpoint | setpoint | Structure | |
mo_setpoint/fixed | fixed | Cell of scalars | true | |
mo_setpoint/start | start | Cell of scalars |
Ports
| Name | Type | Description | IO Type | Number |
|---|---|---|---|---|
fluidPortA | implicit | Hydraulic port A | input | 1 |
fluidPortB | implicit | Hydraulic port B | input | 2 |
flange_a | implicit | input | 3 | |
flange_b | implicit | output | 1 | |
setpoint | implicit | input | 4 | |
Port 6 | implicit | Hydraulic port Leakage | input | mo_useLeakagePort |