Valve Section with Rigid Shaft (IL-PB)

R2026b

Valve section with rigid shaft for hydromechanical valves

Since R2026b

• 

Valve Section with Rigid Shaft (IL-PB) block

To add a block to a model, double-click the canvas and start typing the block name. Then, select the block from the list.

Libraries:
Simscape / Fluids / Isothermal Liquid / Valves & Orifices / Hydromechanical Valves

Description

The Valve Section with Rigid Shaft (IL-PB) block represents a section of a valve with a rigid shaft in the Hydromechanical Valves library. The valve section has rigid spacing along both the valve body and moving spool.

Port Relations

Ports F and B are hydromechanical valve composite ports that have valve_body, spool, and fluid nodes, where:

• Position of F.valve_body relative to B.valve_body is equal to the value of the Valve body section length parameter.

• Position of F.spool relative to B.spool is equal to the value of the Shaft length parameter.

• When you clear Valve section contains liquid, the valve section does not contain liquid and does not use the nodes B.fluid and F.fluid.

• When you select Valve section contains liquid, the block models liquid flow inside the valve section and:

  • The liquid volume is $$V=A\ast L,$$ where L is the value of the Shaft length parameter and A is the value of the Liquid cross-sectional area in valve section parameter.

  • You can enable the isothermal liquid port Af, which models a branching flow path, by selecting Enable port Af for the liquid in the valve section.

Block Sub-Components

The Valve Section with Rigid Shaft (IL-PB) block is equivalent to a composite component comprised of these Simscape Foundation and Fluids library blocks:

• Hydromechanical Valve Interface (IL-PB)

• Translational Spacer (PB)

• Constant Volume Chamber (IL) or Reservoir (IL)

When you select Valve section contains liquid, the equivalent diagram is

When you clear Valve section contains liquid, the equivalent diagram is

Examples

New

Hydromechanical 3-Way Directional Valve with Position Input

Build a 3-way directional valve using components from the Hydromechanical Valves library and compares it to the behavioral 3-Way Directional Valve (IL) block.

• Since R2026b
• Open Live Script

Ports

Conserving

B — Valve body, spool, and fluid

hydromechanical valve composite

Hydromechanical valve composite port that comprises three nodes:

• B.valve_body — Position-based translational node along the valve body.

• B.spool — Position-based translational node that moves along the spool.

• B.fluid — Isothermal liquid node associated with the flow path inside the valve. If you select Valve section contains liquid, this node represents flow to and from an adjacent valve component. Otherwise, this node is unused.

Programmatic Use

Port: B

F — Valve body, spool, and fluid

hydromechanical valve composite

Hydromechanical valve composite port that comprises three nodes:

• F.valve_body — Position-based translational node along the valve body.

• F.spool — Position-based translational node that moves along the spool.

• F.fluid — Isothermal liquid node associated with the flow path inside the valve. If you select Valve section contains liquid, this node represents flow to and from an adjacent valve component. Otherwise, this node is unused.

Programmatic Use

Port: F

Af — Branching flow path

isothermal liquid

Isothermal liquid conserving port that represents a branching flow path for the fluid.

Dependencies

To enable this port, select Valve section contains liquid and Enable port Af for the liquid in valve section.

Programmatic Use

Port: Af

Parameters

Valve body section length — Length of valve body section

0.1 m (default) | positive scalar

Length of the body section of the valve.

Programmatic Use

Parameter: body_length

Shaft length — Length of valve shaft

0.1 m (default) | positive scalar

Length of the valve shaft.

Programmatic Use

Parameter: shaft_length

Valve section contains liquid — Whether valve section contains liquid

on (default) | off

Whether the valve section contains liquid.

Programmatic Use

Parameter:	contains_liquid
Values:	"true" | "false"

Liquid cross-sectional area in valve section — Liquid cross-sectional area

0.01 m^2 (default) | positive scalar

Cross-sectional area of the liquid in the valve

Dependencies

To enable this parameter, select Valve section contains liquid.

Programmatic Use

Parameter: section_area

Enable port Af for the liquid in valve section — Option to enable branching flow path

off (default) | on

Option to enable the isothermal liquid port Af, which represents a branching flow path for the fluid.

Dependencies

To enable this parameter, select Valve section contains liquid.

Programmatic Use

Parameter:	enable_liquid_port
Values:	"true" | "false"

Enable fluid dynamic compressibility — Whether to model fluid dynamic compressibility

off (default) | on

Whether to model the dynamic compressibility of the liquid. Dynamic compressibility affects the transient response of the system at small timescales. If you select this parameter, the pressure responds dynamically based on the accumulation of fluid mass in the volume. If you clear this parameter, the volume does not accumulate mass and the pressure response is instantaneous. Clearing this setting can improve simulation performance, but may have a negative effect on the simulation robustness. Only clear this setting for small fluid volumes or models with long simulation times.

Dependencies

To enable this parameter, select Valve section contains liquid.

Programmatic Use

Parameter:	enable_dynamic_compressibility
Values:	"true" | "false"

Initial liquid pressure — Initial isothermal liquid pressure

0.101325 MPa (default) | positive scalar

Pressure for the isothermal liquid at the start of the simulation.

Dependencies

To enable this parameter, select Valve section contains liquid and Enable fluid dynamic compressibility.

Programmatic Use

Parameter: p_init

Extended Capabilities

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

Version History

Introduced in R2026b