Fixed-Displacement Pump (2P)

Mechanical-hydraulic power conversion device

Since R2022b

• 

Libraries:
Simscape / Fluids / Two-Phase Fluid / Fluid Machines

Description

The Fixed-Displacement Pump (2P) block represents a pump that extracts power from a mechanical rotational network and delivers it to a two-phase fluid network. The pump displacement is fixed at a constant value that you specify through the Displacement parameter.

Ports A and B represent the pump inlets. Ports R and C represent the drive shaft and case. During normal operation, the pressure gain from port A to port B is positive if the angular velocity at port R relative to port C is positive.

The Fixed-Displacement Pump (2P) block assumes that liquid enters the pump inlet. You can use the Report when fluid is not fully liquid parameter to choose what the block does when the fluid does not meet liquid conditions. To move vapor in a two-phase fluid network, use a compressor.

Operating Modes

The block has four modes of operation, as shown by this image.

The working mode depends on the pressure gain from port A to port B, Δp = p_B – p_A and the angular velocity, ω = ω_R – ω_C:

• The quadrant labeled 1 represents the forward pump mode. In this mode, the positive shaft angular velocity causes a pressure increase from port A to port B and flow from port A to port B

• The quadrant labeled 2 represents the reverse motor mode. In this mode, the flow from port B to port A causes a pressure decrease from B to A and negative shaft angular velocity.

• The quadrant labeled 3 represents the reverse pump mode. In this mode, the negative shaft angular velocity causes a pressure increase from port B to port A and flow from port B to port A

• The quadrant labeled 4 represents the forward motor mode. In this mode, the flow from port A to port B causes a pressure decrease from A to B and positive shaft angular velocity.

The response time of the pump is negligible in comparison with the system response time. The pump reaches steady state nearly instantaneously and is treated as a quasi-steady component.

Energy Balance

The block associates the mechanical work done by the pump with an energy exchange. The governing energy balance equation is

$${\varphi }_A+{\varphi }_B+P_{hydro}=0,$$

where:

• Φ_A and Φ_B are the energy flow rates at ports A and B, respectively.

• P_hydro is the pump hydraulic power, which is a function of the pressure difference between the pump ports: $$P_{hydro}=\Delta p\frac{\dot{m}}{\rho }$$.

The block generates mechanical power due to torque, τ, and angular velocity, ω:

$$P_{mech}=\tau \omega .$$

Flow Rate and Driving Torque

The mass flow rate generated at the pump is

$$\dot{m}={\dot{m}}_{\text{Ideal}}-{\dot{m}}_{\text{Leak}},$$

where:

• $$\dot{m}$$ is the actual mass flow rate.

• $${\dot{m}}_{\text{Ideal}}$$ is the ideal mass flow rate.

• $${\dot{m}}_{\text{Leak}}$$ is the internal leakage mas flow rate.

The driving torque required to power the pump is

$$\tau ={\tau }_{\text{Ideal}}+{\tau }_{\text{Friction}},$$

where:

• τ is the actual driving torque.

• τ_Ideal is the ideal driving torque.

• τ_Friction is the friction torque.

Ideal Flow Rate and Ideal Torque

The ideal mass flow rate is

$${\dot{m}}_{\text{Ideal}}=\rho D\omega ,$$

and the ideal required torque is

$${\tau }_{\text{Ideal}}=D\Delta p,$$

where:

• ρ is the average of the fluid densities at ports A and B.

• D is the Displacement parameter.

• ω is the shaft angular velocity.

• Δp is the pressure gain from inlet to outlet.

Leakage and Friction Parameterization

You can parameterize leakage and friction analytically, by using tabulated efficiencies or losses, or by using input efficiencies or input losses.

Analytical

When you set the Leakage and friction parameterization parameter to Analytical, the leakage flow rate is

$${\dot{m}}_{\text{Leak}}=\frac{K_{\text{HP}}{\rho }_{\text{Avg}}\Delta p}{{\mu }_{\text{Avg}}},$$

and the friction torque is

$${\tau }_{\text{Friction}}=\left({\tau }_0+K_{\text{TP}}\left|\Delta p\right|\text{tanh}\frac{4\omega }{\left(5\cdot {10}^{-5}\right){\omega }_{\text{Nom}}}\right),$$

where:

• K_HP is the Hagen-Poiseuille coefficient for laminar pipe flows. The block computes this coefficient from the specified nominal parameters.

• μ is the dynamic viscosity of the fluid, which is the average of the values at the ports.

• K_TP is the friction torque vs. pressure gain coefficient at nominal displacement, which the block determines from the Mechanical efficiency at nominal conditions parameter, η_m:

  $$k=\frac{{\tau }_{fr,nom}-{\tau }_0}{\Delta p_{nom}}.$$

  τ_fr,nom is the friction torque at nominal conditions:

  $${\tau }_{fr,nom}=\left(\frac{1-{\eta }_{m,nom}}{{\eta }_{m,nom}}\right)D\Delta p_{nom}.$$

• Δp_Nom is the value of the Nominal pressure gain parameter. This value is the pressure gain at which the nominal volumetric efficiency is specified.

• τ₀ is the value of the No-load torque parameter.

• ω_Nom is the value of the Nominal shaft angular velocity parameter.

The block determines the Hagen-Poiseuille coefficient from the nominal fluid and component parameters

$$K_{\text{HP}}=\frac{D{\omega }_{\text{Nom}}{\mu }_{\text{Nom}}\left(1-{\eta }_{\text{v,Nom}}\right)}{\Delta p_{\text{Nom}}},$$

where:

• ω_Nom is the value of the Nominal shaft angular velocity parameter. This value is the angular velocity at which the block specifies the nominal volumetric efficiency.

• μ_Nom is the value of the Nominal Dynamic viscosity parameter. This value is the dynamic viscosity at which the block specifies the nominal volumetric efficiency.

• η_v,Nom is the value of the Volumetric efficiency at nominal conditions parameter. This is the volumetric efficiency that corresponds to the specified nominal conditions.

Tabulated Efficiencies

When you set the Leakage and friction parameterization parameter to Tabulated data - volumetric and mechanical efficiencies, the leakage flow rate is

$${\dot{m}}_{\text{Leak}}={\dot{m}}_{\text{Leak,Pump}}\frac{\left(1+\alpha \right)}{2}+{\dot{m}}_{\text{Leak,Motor}}\frac{\left(1-\alpha \right)}{2},$$

and the friction torque is

$${\tau }_{\text{Friction}}={\tau }_{\text{Friction,Pump}}\frac{1+\alpha }{2}+{\tau }_{\text{Friction,Motor}}\frac{1-\alpha }{2},$$

where:

• α is a numerical smoothing parameter for the motor-pump transition.

• $${\dot{m}}_{\text{Leak,Motor}}$$ is the leakage flow rate in motor mode.

• $${\dot{m}}_{\text{Leak,Pump}}$$ is the leakage flow rate in pump mode.

• τ_{Friction,Motor} is the friction torque in motor mode.

• τ_{Friction,Pump} is the friction torque in pump mode.

This hyperbolic function describes the smoothing parameter α

$$\alpha =\text{tanh}\left(\frac{4\Delta p}{\Delta p_{\text{Threshold}}}\right)·\text{tanh}\left(\frac{4\omega }{{\omega }_{\text{Threshold}}}\right),$$

where:

• Δp_Threshold is the value of the Pressure gain threshold for motor-pump transition parameter.

• ω_Threshold is the value of the Angular velocity threshold for motor-pump transition parameter.

The block calculates the leakage flow rate from the volumetric efficiency, which the Volumetric efficiency table parameter specifies over the Δp–ɷ domain. When operating in pump mode, the leakage flow rate is:

$${\dot{m}}_{\text{Leak,Pump}}=\left(1-{\eta }_{\text{v}}\right){\dot{m}}_{\text{Ideal}},$$

where η_v is the volumetric efficiency, which the block obtains either by interpolation or extrapolation of the tabulated data. Similarly, when operating in motor mode, the leakage flow rate is:

$${\dot{m}}_{\text{Leak,Motor}}=-\left(1-{\eta }_{\text{v}}\right)\dot{m}.$$

The block calculates the friction torque from the mechanical efficiency, which the Mechanical efficiency table parameter specifies over the Δp–ɷ domain. When operating in pump mode, the friction torque is

$${\tau }_{\text{Friction,Pump}}=\left(1-{\eta }_{\text{m}}\right)\tau ,$$

where η_m is the mechanical efficiency, which the block obtains either by interpolation or extrapolation of the tabulated data. Similarly, when operating in motor mode, the friction torque is

$${\tau }_{\text{Friction,Motor}}=-\left(1-{\eta }_{\text{m}}\right){\tau }_{\text{Ideal}}.$$

Tabulated Losses

When you set the Leakage and friction parameterization parameter to Tabulated data - volumetric and mechanical losses, the block specifies the leakage volumetric flow rate in tabulated form over the Δp–ɷ domain:

$$q_{\text{Leak}}=q_{\text{Leak}}\left(\Delta p,\omega \right).$$

The block calculates the mass flow rate due to leakage from the volumetric flow rate:

$${\dot{m}}_{\text{Leak}}=\rho q_{\text{Leak}}.$$

The block calculates the friction torque in tabulated form:

$${\tau }_{\text{Friction}}={\tau }_{\text{Loss}}\left(\Delta p,\omega \right)\tanh \left(\frac{4\omega }{{\omega }_{threshold}}\right),$$

where q_Leak(Δp,ω) and τ_Loss(Δp,ω) are the volumetric and mechanical losses, specified through interpolation or extrapolation of the tabulated data in the Volumetric loss table and Mechanical loss table parameters.

Input Efficiencies

When you set the Leakage and friction parameterization parameter to Input signal - volumetric and mechanical efficiencies, the leakage flow rate and friction torque calculations are identical to the Tabulated data - volumetric and mechanical efficiencies setting. The block replaces the volumetric and mechanical efficiency lookup tables with the physical signal input ports EV and EM.

The efficiencies are positive quantities with values between 0 and 1.The block sets input values outside of these bounds to 0 for inputs smaller than 0 or 1 for inputs greater than 1. The block saturates the efficiency signals at the value of the Minimum volumetric efficiency or Minimum mechanical efficiency parameter and the Maximum volumetric efficiency or Maximum mechanical efficiency parameter.

Input Losses

When you set the Leakage and friction parameterization parameter to Input signal - volumetric and mechanical losses, the leakage flow rate and friction torque calculations are identical to the Tabulated data - volumetric and mechanical efficiencies setting. The block replaces the volumetric and mechanical loss lookup tables with the physical signal input ports LV and LM.

The block expects the inputs to be positive and sets the signs automatically from the Δp–ɷ quadrant where the component is operating. If you provide a negative signal, the block returns zero losses.

Faults

To model a fault, in the Faults section, click the Add fault hyperlink next to the fault that you want to model. Use the fault parameters to specify the fault properties. For more information about fault modeling, see Introduction to Simscape Faults.

You can model a displacement fault, leakage, or a shaft friction torque fault.

When you enable the Displacement fault parameter, the block scales the displacement by the value of the Faulted displacement factor parameter when the fault triggers,

$${\text{D}}_{Fault}=f_{D}D,$$

where f_D is the value of the Faulted displacement factor parameter. When the Leakage and friction parameterization parameter is Analytical, the block does not use the faulted displacement value to calculate the Hagen-Poiseuille coefficient or the friction torque at nominal conditions.

When you enable the Leakage fault parameter and Leakage and friction parameterization is Analytical, Tabulated data - volumetric and mechanical efficiencies, or Input signal - volumetric and mechanical efficiencies, the faulted volumetric efficiency is

$${\eta }_{v,Fault}=\frac{{\eta }_v}{f_{Leak}},$$

where f_Leak is the value of the Faulted leakage factor parameter and η_v is the volumetric efficiency. When Leakage and friction parameterization is Analytical, the block uses the faulted volumetric efficiency to calculate the Hagen-Poiseuille coefficient.

When Leakage and friction parameterization is Tabulated data - volumetric and mechanical losses or Input signal - volumetric and mechanical losses, the faulted leakage volumetric flow rate is

$$q_{Leak,Fault}=f_{Leak}{q}_{Leak}.$$

When you enable the Shaft friction torque fault parameter and Leakage and friction parameterization is Analytical, Tabulated data - volumetric and mechanical efficiencies, or Input signal - volumetric and mechanical efficiencies, the faulted mechanical efficiency is

$${\eta }_{m,Fault}=\frac{{\eta }_m}{f_{Friction}},$$

where f_Friction is the value of the Faulted shaft friction torque factor parameter and η_m is the mechanical efficiency. When Leakage and friction parameterization is Analytical, the block uses the faulted mechanical efficiency to calculate the friction torque at nominal conditions.

When Leakage and friction parameterization is Tabulated data - volumetric and mechanical losses or Input signal - volumetric and mechanical losses, the faulted friction torque is

$${\tau }_{Friction,Fault}=f_{Friction}{\tau }_{Friction}.$$

Assumptions and Limitations

• The block treats the pump as a quasi-steady component.

• The block ignores the effects of fluid inertia and elevation.

• The pump wall is rigid.

• The block ignores external leakage.

Ports

Input

EV — Volumetric efficiency, unitless

physical signal

Physical signal input port for the volumetric efficiency coefficient. The input signal has an upper bound at the Maximum volumetric efficiency parameter value and a lower bound at the Minimum volumetric efficiency parameter value.

Dependencies

To enable this port, set Leakage and friction parameterization to Input signal - volumetric and mechanical efficiencies.

EM — Mechanical efficiency, unitless

physical signal

Physical signal input port for the mechanical efficiency coefficient. The input signal has an upper bound at the Maximum mechanical efficiency parameter value and a lower bound at the Minimum mechanical efficiency parameter value.

Dependencies

To enable this port, set Leakage and friction parameterization to Input signal - volumetric and mechanical efficiencies.

LV — Volumetric loss, m^3/s

physical signal

Physical signal input port for the volumetric loss which is the internal leakage flow rate between the pump inlets.

Dependencies

To enable this port, set Leakage and friction parameterization to Input signal - volumetric and mechanical losses.

LM — Mechanical loss, N*m

physical signal

Physical signal input port for the mechanical loss which is the friction torque on the rotating pump shaft.

Dependencies

To enable this port, set Leakage and friction parameterization to Input signal - volumetric and mechanical losses.

Conserving

A — Pump inlet

two-phase fluid

Two-phase fluid conserving port associated with the pump inlet.

B — Pump outlet

two-phase fluid

Two-phase fluid conserving port associated with the pump outlet.

C — Pump case

mechanical rotational

Mechanical rotational conserving port associated with the pump case.

R — Pump shaft

mechanical rotational

Mechanical rotational conserving port associated with the rotational pump shaft.

Parameters

Parameters

Leakage and friction parameterization — Parameterization of leakage flow rate and friction torque

Analytical (default) | Tabulated data - volumetric and mechanical efficiencies | Tabulated data - volumetric and mechanical losses | Input signal - volumetric and mechanical efficiencies | Input signal - volumetric and mechanical losses

Method to compute the flow-rate and torque losses due to internal leaks and friction. Use the Analytical if the block parameters are generally available from component data sheets. When you select Tabulated data - volumetric and mechanical efficiencies or Tabulated data - volumetric and mechanical losses, the block uses lookup tables to map pressure gains and shaft angular velocities to component efficiencies or losses.

When you select Input signal - volumetric and mechanical efficiencies or Input signal - volumetric and mechanical losses, the block performs the leakage flow rate and friction torque calculations the same as the Tabulated data - volumetric and mechanical efficiencies or Tabulated data - volumetric and mechanical losses settings, respectively. When you select Input signal - volumetric and mechanical efficiencies, the block enables the EV and EM ports. You use these ports to specify the volumetric and mechanical efficiency. When you select Input signal - volumetric and mechanical losses, the block enables the LV and LM ports. You use these ports to specify the volumetric and mechanical losses.

Displacement — Fluid volume displaced per shaft rotation

30 cm^3/rev (default) | positive scalar

Fluid volume displaced per shaft rotation. The block maintains this value throughout the simulation.

Nominal shaft angular velocity — Shaft angular velocity for given volumetric efficiency

1800 rpm (default) | scalar

Angular velocity of the rotary shaft that corresponds to the given volumetric efficiency. The standard operating conditions in the manufacturer data sheet typically list these values. The block uses this parameter to calculate the leakage flow rate and friction torque.

Dependencies

To enable this parameter, set Leakage and friction parameterization to Analytical.

Nominal pressure gain — Pressure gain for corresponding volumetric efficiency

10 MPa (default) | scalar

Pressure gain that corresponds to the given volumetric efficiency. The standard operating conditions in the manufacturer data sheet typically list these values. The block uses this parameter to calculate the internal leakage flow rate.

Dependencies

To enable this parameter, set Leakage and friction parameterization to Analytical.

Nominal dynamic viscosity — Dynamic viscosity at which to specify the volumetric efficiency

0.9 cP (default) | scalar

Dynamic viscosity of the hydraulic fluid for the given volumetric efficiency. The standard operating conditions in the manufacturer data sheet typically list these values. The block uses this parameter to calculate the internal leakage flow rate.

Dependencies

To enable this parameter, set Leakage and friction parameterization to Analytical.

Volumetric efficiency at nominal conditions — Volumetric efficiency at specified nominal conditions

0.92 (default) | positive scalar

Volumetric efficiency for the given conditions. The block defines the volumetric efficiency as the ratio of actual to ideal volumetric flow rates. The standard operating conditions in the manufacturer data sheet typically list these values. The block uses this parameter to calculate the internal leakage flow rate.

Dependencies

To enable this parameter, set Leakage and friction parameterization to Analytical.

Mechanical efficiency at nominal conditions — Ratio of ideal-to-actual mechanical power

0.88 (default) | positive scalar

Ratio of ideal mechanical power to actual mechanical power at nominal conditions.

Dependencies

To enable this parameter, set Leakage and friction parameterization to Analytical.

No-load torque — Minimum torque required to induce shaft rotation

0 N*m (default) | scalar

Torque to overcome the seal friction and induce rotation of the mechanical shaft. This torque is the load-independent component of the total friction torque.

Dependencies

To enable this parameter, set Leakage and friction parameterization to Analytical.

Pressure gain vector, dp — Pressure gains for given volumetric and mechanical efficiencies or losses

[.1, 1, 2] MPa (default) | vector

Pressure gains for the corresponding tabular efficiency or loss data. The vector must be at least two elements in strictly increasing order.

Specify the data for a single quadrant, (ɷ, Δp). Refer to Operating Modes for the operation modes corresponding to parameter specifications and the resulting quadrants.

Dependencies

To enable this parameter, set Leakage and friction parameterization to Tabulated data - volumetric and mechanical efficiencies or Tabulated data - volumetric and mechanical losses.

Shaft angular velocity vector, w — Angular velocities at which to specify volumetric and mechanical efficiencies or losses

[250, 500, 1000, 2000, 3000, 4000] rpm (default) | vector

Shaft angular velocities for the corresponding tabular efficiency or loss data. The vector must be at least two elements in strictly increasing order.

Specify the data for a single quadrant, (ɷ, Δp). Refer to Operating Modes for the operation modes corresponding to parameter specifications and the resulting quadrants.

Dependencies

To enable this parameter, set Leakage and friction parameterization to Tabulated data - volumetric and mechanical efficiencies or Tabulated data - volumetric and mechanical losses.

Volumetric efficiency table, e_v(dp,w) — Volumetric efficiencies for given pressure gains and angular velocities

[.816, .908, .954, .977, .981, .984; .325, .663, .831, .916, .925, .946; .137, .568, .78, .892, .893, .91] (default) | matrix

Volumetric efficiencies for the given fluid pressure gains and shaft angular velocities. The efficiencies must be in the range (0,1]. M and N are the sizes of the specified lookup-table vectors:

• M is the number of vector elements in the Pressure gain vector, dp parameter.

• N is the number of vector elements in the Shaft angular velocity vector, w parameter.

Specify the data for a single quadrant, (ɷ, Δp). Refer to Operating Modes for the operation modes corresponding to parameter specifications and the resulting quadrants.

Dependencies

To enable this parameter, set Leakage and friction parameterization to Tabulated data - volumetric and mechanical efficiencies.

Mechanical efficiency table, e_m(dp,w) — Mechanical efficiencies for given pressure gains and angular velocities

[.996, .996, .996, .996, .996, .996; .988, .989, .989, .989, .989, .99; .981, .981, .982, .982, .983, .984] (default) | matrix

Mechanical efficiencies for the given fluid pressure gains and shaft angular velocities. The efficiencies must be in the range (0,1]. M and N are the sizes of the specified lookup-table vectors:

• M is the number of vector elements in the Pressure gain vector, dp parameter.

• N is the number of vector elements in the Shaft angular velocity vector, w parameter.

Specify the data for a single quadrant, (ɷ, Δp). Refer to Operating Modes for the operation modes corresponding to parameter specifications and the resulting quadrants.

Dependencies

To enable this parameter, set Leakage and friction parameterization to Tabulated data - volumetric and mechanical efficiencies.

Volumetric loss table, q_loss(dp,w) — Internal leakage flow rates for corresponding pressure gains and angular velocities

[.023, .023, .023, .023, .0285, .032; .0844, .0842, .0845, .084, .1125, .108; .1079, .108, .11, .108, .1605, .18] * 1e-3 m^3/s (default) | matrix

Volumetric losses at the specified fluid pressure gains and shaft angular velocities. Volumetric loss is the internal leakage volumetric flow rate between port A and port B. M and N are the sizes of the specified lookup-table vectors:

• M is the number of vector elements in the Pressure gain vector, dp parameter.

• N is the number of vector elements in the Shaft angular velocity vector, w parameter.

Specify the data for a single quadrant, (ɷ, Δp). Refer to Operating Modes for the operation modes corresponding to parameter specifications and the resulting quadrants.

Dependencies

To enable this parameter, set Leakage and friction parameterization to Tabulated data - volumetric and mechanical losses.

Mechanical loss table, torque_loss(dp,w) — Friction torques for corresponding pressure gains and angular velocities

[.002, .002, .002, .002, .002, .002; .0607, .0556, .0556, .0556, .0556, .0505; .1937, .1937, .1833, .1833, .1729, .1626] N*m (default) | matrix

Mechanical losses for the given pressure gains and shaft angular velocities. The block defines mechanical loss as the friction torque due to seals and internal components. M and N are the sizes of the specified lookup-table vectors:

• M is the number of vector elements in the Pressure gain vector, dp parameter.

• N is the number of vector elements in the Shaft angular velocity vector, w parameter.

Specify the data for a single quadrant, (ɷ, Δp). Refer to Operating Modes for the operation modes corresponding to parameter specifications and the resulting quadrants. The tabulated data for the mechanical losses must obey the convention in the figure, with positive values at positive angular velocities and negative values at negative angular velocities.

Dependencies

To enable this parameter, set Leakage and friction parameterization to Tabulated data - volumetric and mechanical losses.

Minimum volumetric efficiency — Lower saturation bound on volumetric efficiency input signal

1e-3 (default) | scalar in the range (0,1)

Smallest allowed value of the volumetric efficiency. The input from the physical signal port EV saturates inputs below this value.

Dependencies

To enable this parameter, set Leakage and friction parameterization to Input signal - volumetric and mechanical efficiencies.

Maximum volumetric efficiency — Upper saturation bound on volumetric efficiency input signal

1 (default) | positive scalar

Largest allowed value of the volumetric efficiency. The input from the physical signal port EV saturates inputs above this value.

Dependencies

To enable this parameter, set Leakage and friction parameterization to Input signal - volumetric and mechanical efficiencies.

Minimum mechanical efficiency — Lower saturation bound on volumetric efficiency input signal

1e-3 (default) | scalar in the range (0,1)

Smallest allowed value of the mechanical efficiency. The input from the physical signal port EM saturates inputs below this value.

Dependencies

To enable this parameter, set Leakage and friction parameterization to Input signal - volumetric and mechanical efficiencies.

Maximum mechanical efficiency — Upper saturation bound on volumetric efficiency input signal

1 (default) | scalar in the range (0,1)

Largest allowed value of the mechanical efficiency. The input from the physical signal port EM saturates inputs above this value.

Dependencies

To enable this parameter, set Leakage and friction parameterization to Input signal - volumetric and mechanical efficiencies.

Pressure gain threshold for motor-pump transition — Pressure gain at which to initiate smooth transition between motor and pump modes

1e-3 MPa (default) | scalar

Pressure gain from the inlet to the outlet below which the block begins to transition between the motor and pump modes. The block uses a hyperbolic tangent function to smooth the leakage flow rate and friction torque.

Dependencies

To enable this parameter, set Leakage and friction parameterization to Input signal - volumetric and mechanical efficiencies or Input signal - volumetric and mechanical losses.

Angular velocity threshold for motor-pump transition — Angular velocity at which to initiate smooth transition between pump and motor modes

100 rpm (default) | scalar

Shaft angular velocity below which the block begins to transition between the motor and pump modes. The block uses the hyperbolic tangent function to smooth the leakage flow rate and friction torque.

Dependencies

To enable this parameter, set Leakage and friction parameterization to Input signal - volumetric and mechanical efficiencies or Input signal - volumetric and mechanical losses.

Cross-sectional area at ports A and B — Flow area at component inlet and outlet

0.01 m^2 (default) | positive scalar

Flow area at the component inlet and outlet. The areas are assumed equal.

Report when fluid is not fully liquid — Notification when fluid is not fully liquid

None (default) | Warning | Error

Whether the block does nothing, generates a warning, or generates an error when the vapor quality is greater than 0, which indicates that the fluid is not fully liquid.

Check if operating beyond the range of supplied tabulated data — Simulation warning mode for operating conditions outside range of tabulated data

None (default) | Warning | Error

Simulation warning mode for operating conditions outside the range of tabulated data. If you select Warning, the block generates a warning when the fluid pressure gain or the shaft angular velocity cross outside the specified tabular data. The warning does not cause simulation to stop. If you select Error, the simulation will stop for conditions outside the range of tabulated data.

Dependencies

To enable this parameter, set Leakage and friction parameterization to:

• Tabulated data - volumetric and mechanical efficiencies

• Tabulated data - volumetric and mechanical losses

Check if operating outside of pump mode — Simulation warning mode for operating conditions outside pump mode

None (default) | Warning | Error

Simulation warning mode for operating conditions outside the pump mode. When you set this parameter to Warning, the block generates a warning if the pump transitions to motoring mode. The warning does not cause simulation to stop. If you select Error, the simulation will stop for conditions outside the pump mode.

Dependencies

To enable this parameter, set Leakage and friction parameterization to Input signal - volumetric and mechanical losses.

Faults

Displacement fault — Option to model displacement fault

Add fault

Option to model a displacement fault in the block. When a fault occurs, the displacement scales by the value of the Faulted displacement factor parameter. To add a fault, click the Add fault hyperlink.

Faulted displacement factor — Factor by which to scale faulted displacement

0.5 (default) | positive scalar

Factor that the block uses to scale the displacement when a fault occurs.

Dependencies

To enable this parameter, click the Add fault hyperlink for the Displacement fault parameter.

Leakage fault — Option to model leakage fault

Add fault

Option to model a leakage fault in the block. When a fault occurs, the volumetric efficiencies or losses scale by the value of the Faulted leakage factor parameter. To add a fault, click the Add fault hyperlink.

Faulted leakage factor — Factor by which to scale leakage fault

2.0 (default) | positive scalar

Factor that the block uses to scale the volumetric efficiencies or losses when a fault occurs.

Dependencies

To enable this parameter, click the Add fault hyperlink for the Leakage fault parameter.

Shaft friction torque fault — Option to model shaft friction torque fault

Add fault

Option to model a shaft friction torque fault in the block. When a fault occurs, the mechanical efficiencies or losses scale by the value of the Faulted shaft friction torque factor parameter. To add a fault, click the Add fault hyperlink.

Faulted shaft friction torque factor — Factor by which to scale shaft friction torque fault

2.0 (default) | positive scalar

Factor that the block uses to scale the mechanical efficiencies or losses when a fault occurs.

Dependencies

To enable this parameter, click the Add fault hyperlink for the Shaft friction torque fault parameter.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

Version History

Introduced in R2022b

R2024b: Model faults with the Simscape faults interface

The Fixed-Displacement Pump (2P) block now supports the Simscape faults interface. To learn more, see Introduction to Simscape Faults.

R2024a: Check if block operates outside range of calculated data

The Check if operating beyond the quadrants of supplied tabulated data parameter has been renamed to Check if operating beyond the range of supplied tabulated data. You can enable the Check if operating beyond the range of supplied tabulated data parameter to check if the block is operating beyond the data specified in the block parameters, that is, operating in a region where the block has extended the data.