Valve Port with Land Edge at B (IL-PB)

R2026b

Valve port with land edge at port B for hydromechanical valves

Since R2026b

• 

Valve Port with Land Edge at B (IL-PB) block

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

Description

The Valve Port with Land Edge at B (IL-PB) block represents a valve port and a spool land that meters flow with its edge at port B. The metering area increases as the land moves in the positive direction relative to the valve port. This movement creates a flow path between ports Af and B. To model this component the land edge on the opposite side, use the Valve Port with Land Edge at F (IL-PB) block.

Use the Flow momentum force model parameter to specify the method the block uses to calculate the flow momentum force. The block always models the pressure force. The block calculates the pressure force by multiplying the gauge pressure at B.fluid by the land area. A positive fluid force pushes the land in the positive direction, and a negative fluid force pushes the land in the negative direction.

Port Relations

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

• The positions of B.valve_body and F.valve_body are equal.

• The position of F.spool relative to B.spool is the value of the Land width along valve axis parameter.

The opening distance is the position of B.spool relative to the valve port edge on side of port B. If Metering edge geometry is Sharp Edge, the flow path is closed at an opening distance of 0. If Metering edge geometry is Chamfer, the flow path is fully closed when the opening distance is equal to the negative of the value of the Chamfer setback parameter.

Metering Area

The metering area depends on the metering edge and valve port geometry.

Sharp Edge Metering Edge

When Metering edge geometry is Sharp Edge and Valve port geometry is Regular slot, the metering area and maximum metering area are

$$\begin{array}{l}A=x{l}_p\\ A_{max}=w_p{l}_p\end{array}$$

where:

• x is the distance between the port edge and the land piston face.

• l_p is the value of the Port length along valve circumference parameter.

• w_p is the value of the Port width along valve axis parameter.

When Valve port geometry is Round holes, the metering area and maximum metering area are

$$\begin{array}{l}A=\frac{n_p{d}_p^2}{4}\left[\left(\frac{2x}{d_p}-1\right)\sqrt{1-{\left(\frac{2x}{d_p}-1\right)}^2}+\arcsin \left(\frac{2x}{d_p}-1\right)+\frac{\pi }{2}\right]\\ A_{max}=\frac{n_p\pi d_p^2}{4}\end{array}$$

where:

• n_p is the value of the Number of holes along valve circumference parameter.

• d_p is the value of the Hole diameter parameter.

Chamfer Metering Edge

When Metering edge geometry is Chamfer and Valve port geometry is Regular slot, the metering area and maximum metering area are

$$\begin{array}{l}A=\{\begin{array}{ll}\left(x+w_c\right)l_p\sin {\theta }_c,\hfill & x\le w_c{\tan }^2{\theta }_c\hfill \\ l_p\sqrt{x^2+{\left(w_{c}tan{\theta }_c\right)}^2},\hfill & w_c{\tan }^2{\theta }_c<x\le w_p-w_c\hfill \\ l_p\sqrt{x^2+{\left[\left(w_p-x\right)tan{\theta }_c\right]}^2},\hfill & x>w_p-w_c\hfill \end{array}\\ A_{max}=w_p{l}_p\end{array}$$

where:

• w_c is the value of the Chamfer setback along valve axis parameter.

• θ_c is the value of the Chamfer angle with respect to valve axis parameter.

When Valve port geometry is Round holes, the metering area and maximum metering area are

$$\begin{array}{l}A=\{\begin{array}{ll}\frac{n_p{d}_p^2\sin {\theta }_c}{4}\left[\left(\frac{2x_{c1}}{d_p}-1\right)\sqrt{1-{\left(\frac{2x_{c1}}{d_p}-1\right)}^2}+\arcsin \left(\frac{2x_{c1}}{d_p}-1\right)+\frac{\pi }{2}\right],\hfill & x\le w_c{\tan }^2{\theta }_c\hfill \\ \frac{n_p{d}_p^2\sin {\theta }_{c2}}{4}\left[\left(\frac{2x_{c2}^2}{d_{p}x}-1\right)\sqrt{1-{\left(\frac{2x_{c2}^2}{d_{p}x}-1\right)}^2}+\arcsin \left(\frac{2x_{c2}^2}{d_{p}x}-1\right)+\frac{\pi }{2}\right],\hfill & w_c{\tan }^2{\theta }_c<x\le w_p-w_c\hfill \\ \frac{n_p{d}_p^2\sin {\theta }_{c3}}{4}\left[\left(\frac{2x_{c3}^2}{d_{p}x}-1\right)\sqrt{1-{\left(\frac{2x_{c3}^2}{d_{p}x}-1\right)}^2}+\arcsin \left(\frac{2x_{c3}^2}{d_{p}x}-1\right)+\frac{\pi }{2}\right],\hfill & x>w_p-w_c\hfill \end{array}\\ A_{max}=\frac{n_p\pi d_p^2}{4}\end{array}$$

where:

$$\begin{array}{l}{x}_{c1}=x+w_c\\ x_{c2}=\sqrt{x^2+{\left(w_{c}tan{\theta }_c\right)}^2}\\ x_{c3}=\sqrt{x^2+{\left[\left(w_p-x\right)tan{\theta }_c\right]}^2}\\ \sin {\theta }_{c2}=\frac{x}{\sqrt{x^2+{\left(w_{c}tan{\theta }_c\right)}^2}}\\ \sin {\theta }_{c3}=\frac{x}{\sqrt{x^2+{\left[\left(w_p-x\right)tan{\theta }_c\right]}^2}}\end{array}$$

Tabulated Metering Area

When Metering edge geometry is Tabulated metering area, the block uses a lookup table to determine the metering area from the Opening distance vector and Metering area vector parameters.

Jet Angle Calculations and Flow Effects

When Flow momentum force model is None, the block does not include the flow momentum force. However, it does model the pressure force.

When Flow momentum force model is Based on von Mises jet angle, the jet angle is

$$\cos \alpha =\cos {\alpha }_{metering}+\frac{\cos {\alpha }_{cracking}-\cos {\alpha }_{metering}}{1+0.642{\left(\frac{\overline{x}}{c}\right)}^{1.26}}$$

where:

• α_cracking is the value of the Cracking jet angle for valve port inflow or Cracking jet angle for valve port outflow parameter, depending on the direction of the flow at port Af.

• α_metering is the value of the Metering jet angle for valve port inflow or Metering jet angle for valve port outflow parameter, depending on the direction of the flow at port Af.

• $$\overline{x}$$ is the distance between the port edge and the land piston face, except when Metering edge geometry is Chamfer. In that case, $$\overline{x}$$= x+w_c.

When the opening moves beyond the fully open or fully closed positions, the block smoothly transitions the jet angle to 90° over a distance of 0.1 multiplied by the value of either the Port width along valve axis or Hole diameter parameter. Because of the jet angle saturation, the flow momentum force smoothly transitions to zero when the land edge moves away from the valve port.

The block does not modify the jet angle calculation for metering edge geometry modifications such as chamfers because the geometry and fluid jet interaction is too complex to approximate with a lumped parameter model. If your system uses machined geometry modifications to the land edge to mitigate the flow momentum force, estimate the jet angle empirically by either fitting the von Mises jet angle parameterization or using the tabulated parameterization.

When Flow momentum force model is Based on tabulated jet angle, the block calculates the jet angle by using a lookup table from the Opening distance vector for jet angle parameter and either the Jet angle vector for valve port inflow or Jet angle vector for valve port outflow parameter, depending on the direction of the flow at port Af.

The flow momentum force is

$$F_{flow}=-\frac{{\dot{m}}^2}{\rho }\left(\frac{\cos \alpha }{A}\right).$$

Mass Flow Rate

The mass flow rate through the fluid flow path is

$$\dot{m}=\frac{\Delta p}{{\left(\Delta p^2+\Delta p_{crit}{}^2\right)}^{1/4}}{\left(\frac{2{\rho }_{avg}}{1-A_r{}^2}\right)}^{1/2}{C}_{d}A,$$

where:

• Δp is the pressure differential.

• Δp_crit is the critical pressure differential.

• ρ_avg is the average fluid density.

• A_r is the ratio from the metering area to the connecting area.

• C_d is the value of the Discharge coefficient parameter.

• A is the metering area.

The critical pressure differential is

$$\Delta p_{crit}=\frac{\pi }{4}\frac{{\rho }_{avg}}{2A}{\left(\frac{R{e}_c\nu }{C_d}\right)}^2,$$

where:

• Re_c is the value of the Critical Reynolds number parameter.

• ν is the fluid kinematic viscosity.

Block Sub-Components

The Valve Port with Land Edge at B (IL-PB) block is equivalent to a composite component that comprises these Simscape Foundation and Fluids library blocks:

• Hydromechanical Valve Interface (IL-PB)

• Local Restriction (IL)

• Pressure Sensor (IL)

• Reservoir (IL)

• Ideal Translational Motion Sensor

• Mass (PB), if you select Enable land mass.

• Translational Damper (PB), if you select Enable damping between land and valve body. The damping coefficient is

  $$c_{damping}=\frac{k_{scale}\pi d_{land}{w}_{land}\mu }{h_{clearance}}$$

  where:

  • k_scale is the value pf the Damping scale factor parameter.

  • d_land is the value of the Land outer diameter parameter.

  • w_land is the value of the Land width along valve axis parameter.

  • h_clearance is the value of the Radial clearance between land and valve body parameter.

  • μ is the fluid dynamic viscosity.

• Force Actuator (PB)

• Translational Spacer (PB)

The equivalent diagram is:

Variables

To set the priority and initial target values for the block variables prior to simulation, use the Initial Targets section in the block dialog box or Property Inspector. For more information, see Set Priority and Initial Target for Block Variables.

Nominal values provide a way to specify the expected magnitude of a variable in a model. Using system scaling based on nominal values increases the simulation robustness. Nominal values can come from different sources, one of which is the Nominal Values section in the block dialog box or Property Inspector. For more information, see Modify Nominal Values for a Block Variable.

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 port, land, and fluid

hydromechanical valve composite

Hydromechanical valve composite port that comprises three nodes:

• B.valve_body — Position-based translational node along the valve body. This node represents the center of the valve port.

• B.spool — Position-based translational node along the moving spool. This node represents the land edge.

• B.fluid — Isothermal liquid node associated with the flow path inside the valve. This node represents the fluid flow to an adjacent valve component.

Programmatic Use

Port: B

F — Valve port, land, and fluid

hydromechanical valve composite

Hydromechanical valve composite port that comprises three nodes:

• F.valve_body — Position-based translational node along the valve body. This node represents the center of the valve port.

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

• F.fluid — Isothermal liquid node associated with the flow path inside the valve. This node is unused because the land blocks liquid flow. The adjacent valve component on this side cannot contain liquid.

Programmatic Use

Port: F

Af — Valve port

isothermal liquid

Isothermal liquid conserving port associated with the port on the valve body.

Programmatic Use

Port: Af

Parameters

Flow Metering

Metering edge geometry — Shape of metering edge

Sharp Edge (default) | Chamfer | Tabulated metering area

Shape of the metering edge.

Programmatic Use

Parameter:	metering_geometry
Values:	"fluids.isothermal_liquid.valves_orifices.hydromechanical_valves.enum.MeteringGeometry.SharpEdge" | "fluids.isothermal_liquid.valves_orifices.hydromechanical_valves.enum.MeteringGeometry.Chamfer" | "fluids.isothermal_liquid.valves_orifices.hydromechanical_valves.enum.MeteringGeometry.TabulatedMetering"

Chamfer setback along valve axis — Chamfer setback

1e-3 m (default) | positive scalar

Chamfer setback in the direction along the valve axis. If the spool moves in the horizontal direction, this parameter is in the horizontal direction.

This value is w_c in this diagram:

Dependencies

To enable this parameter, set Metering edge geometry to Chamfer.

Programmatic Use

Parameter: chamfer_setback

Chamfer angle with respect to valve axis — Chamfer angle

45 deg (default) | scalar between 0 and 90

Chamfer angle measured with respect to the valve axis. If the spool moves in the horizontal direction, this parameter is measured with respect to the horizontal.

This value is θ_c in this diagram:

Dependencies

To enable this parameter, set Metering edge geometry to Chamfer.

Programmatic Use

Parameter: chamfer_angle

Opening distance vector — Opening distance data

0 : 0.002 : 0.01 m (default) | vector

Opening distance values that correspond to the values in the Metering area vector parameter.

Dependencies

To enable this parameter, set Metering edge geometry to Tabulated metering area.

Programmatic Use

Parameter: opening_TLU

Metering area vector — Metering area data

[1e-06, .2, .4, .6, .8, 1] * 1e-4 m^2 (default) | vector

Metering area values that correspond to the values in the Opening distance vector parameter.

Dependencies

To enable this parameter, set Metering edge geometry to Tabulated metering area.

Programmatic Use

Parameter: area_TLU

Valve port geometry — Shape of valve port

Rectangular slot (default) | Round holes

Shape of valve ports. When you select Rectangular slot, the block models one rectangular port. When you select Round holes, the block models multiple holes around the circumference of the valve.

Dependencies

To enable this parameter, set Metering edge geometry to Sharp Edge or Chamfer.

Programmatic Use

Parameter:	port_geometry
Values:	"fluids.isothermal_liquid.valves_orifices.hydromechanical_valves.enum.PortGeometry.RectangularSlot" | "fluids.isothermal_liquid.valves_orifices.hydromechanical_valves.enum.PortGeometry.RoundHoles"

Port width along valve axis — Rectangular valve port width

0.01 m (default) | positive scalar

Width of the rectangular valve port, defined along the direction of the valve axis.

Dependencies

To enable this parameter, set Metering edge geometry to Tabulated metering area, or set Metering edge geometry to Sharp Edge or Chamfer and Valve port geometry to Rectangular slot.

Programmatic Use

Parameter: port_width

Port length along valve circumference — Rectangular valve port length

0.01 m (default) | positive scalar

Length of the rectangular valve port, defined along the direction of the valve circumference.

Dependencies

To enable this parameter, set Metering edge geometry to Sharp Edge or Chamfer and set Valve port geometry to Rectangular slot.

Programmatic Use

Parameter: port_length

Hole diameter — Diameter of holes

5e-3 m (default) | positive scalar

Diameter of each hole along the valve circumference.

Dependencies

To enable this parameter, set Metering edge geometry to Sharp Edge or Chamfer and set Valve port geometry to Round holes.

Programmatic Use

Parameter: hole_diameter

Number of holes along valve circumference — Number of round holes

6 (default) | positive integer

Number of holes. The holes are evenly spaced around the circumference of the valve.

Dependencies

To enable this parameter, set Metering edge geometry to Sharp Edge or Chamfer and set Valve port geometry to Round holes.

Programmatic Use

Parameter: num_holes

Fraction of minimum to maximum metering area — Ratio of minimum to maximum metering area

1e-6 (default) | positive scalar

Ratio of the minimum metering area to the maximum metering area. The block uses this parameter to calculate the minimum metering area.

Dependencies

To enable this parameter, set Metering edge geometry to Sharp Edge or Chamfer.

Programmatic Use

Parameter: min_area_fraction

Area of connecting fluid channel at valve port — Cross-sectional area of fluid channel

1e-3 m^2 (default) | positive scalar

Cross-sectional area of the fluid channel at the location of the valve port.

Programmatic Use

Parameter: connecting_area

Discharge coefficient — Discharge coefficient

0.64 (default) | positive scalar in the range of [0,1]

Correction factor that accounts for discharge losses in theoretical flows.

Programmatic Use

Parameter: Cd

Critical Reynolds number — Upper Reynolds number limit for laminar flow

150 (default) | positive scalar

Upper Reynolds number limit for laminar flow through the component.

Programmatic Use

Parameter: Re_c

Spool Land

Land width along valve axis — Land width

0.05 m (default) | positive scalar

Land width, defined along the direction of the valve axis.

Programmatic Use

Parameter: land_width

Land area for liquid pressure force — Land surface area

0.01 m^2 (default) | positive scalar

Effective surface area of the valve land over which the fluid pressure acts.

Programmatic Use

Parameter: land_area

Enable land mass — Option to model land mass

off (default) | on

Option to model land mass.

Programmatic Use

Parameter:	enable_land_mass
Values:	"true" | "false"

Land mass — Mass of land

0.5 kg (default) | positive scalar

Mass of the land.

Dependencies

To enable this parameter, select Enable land mass.

Programmatic Use

Parameter: land_mass

Enable damping between land and valve body — Option to model damping

off (default) | on

Option to model damping between the land and the valve body.

Programmatic Use

Parameter:	enable_damping
Values:	"true" | "false"

Damping scale factor — Scale factor for damping

1 (default) | positive scalar

Scale factor for damping between the land and the valve body. Adjust the value of this parameter to empirically tune the damping in the valve.

Dependencies

To enable this parameter, select Enable damping between land and valve body.

Programmatic Use

Parameter: damping_scale

Land outer diameter — Outer diameter of land

0.1 m (default) | positive scalar

Outer diameter of the land.

Dependencies

To enable this parameter, select Enable damping between land and valve body.

Programmatic Use

Parameter: land_diameter

Radial clearance between land and valve body — Distance between land and valve

5e-6 m (default) | positive scalar

Distance between the land outer land edge and the valve body, defined along the radial direction.

Dependencies

To enable this parameter, select Enable damping between land and valve body or set Flow momentum force model to Based on von Mises jet angle.

Programmatic Use

Parameter: radial_clearance

Flow Effects

Flow momentum force model — Method for modeling flow momentum force

None (default) | Based on von Mises jet angle | Based on tabulated jet angle

Method for modeling flow momentum force on the land. If you select None, the block does not model flow momentum force on the land.

Programmatic Use

Parameter:	flow_force_model
Values:	"fluids.isothermal_liquid.valves_orifices.hydromechanical_valves.enum.SpoolFlowForceModel.None" | "fluids.isothermal_liquid.valves_orifices.hydromechanical_valves.enum.SpoolFlowForceModel.VonMisesJetAngle" | "fluids.isothermal_liquid.valves_orifices.hydromechanical_valves.enum.SpoolFlowForceModel.TabulatedJetAngle"

Cracking jet angle for valve port inflow — Port inflow cracking jet angle

21 deg (default) | scalar between 0 and 180

Jet angle for the inflow through the port when the valve begins to open. The value of this parameter must be less than or equal to the value of the Metering jet angle for valve port inflow parameter.

Dependencies

To enable this parameter, set Flow momentum force model to Based on von Mises jet angle.

Programmatic Use

Parameter: jet_angle_cracking_inflow

Metering jet angle for valve port inflow — Port inflow metering jet angle

69 deg (default) | scalar between 0 and 180

Jet angle for the inflow through the port when the valve operates in the metering region. The value of this parameter must be greater than or equal to the value of the Cracking jet angle for valve port inflow parameter.

Dependencies

To enable this parameter, set Flow momentum force model to Based on von Mises jet angle.

Programmatic Use

Parameter: jet_angle_metering_inflow

Cracking jet angle for valve port outflow — Port outflow cracking jet angle

21 deg (default) | scalar between 0 and 180

Jet angle for the outflow through the port when the valve begins to open. The value of this parameter must be less than or equal to the value of the Metering jet angle for valve port outflow parameter.

Dependencies

To enable this parameter, set Flow momentum force model to Based on von Mises jet angle.

Programmatic Use

Parameter: jet_angle_cracking_outflow

Metering jet angle for valve port outflow — Port outflow metering jet angle

69 deg (default) | scalar between 0 and 180

Jet angle for the outflow through the port when the valve operates in the metering region. The value of this parameter must be greater than or equal to the value of the Cracking jet angle for valve port outflow parameter.

Dependencies

To enable this parameter, set Flow momentum force model to Based on von Mises jet angle.

Programmatic Use

Parameter: jet_angle_metering_outflow

Opening distance vector for jet angle — Opening distance vector

0 : 0.002 : 0.01 m (default) | vector

Opening distance values for the jet angle values for inflow and outflow through the valve.

Dependencies

To enable this parameter, set Flow momentum force model to Based on tabulated jet angle.

Programmatic Use

Parameter: opening_jet_TLU

Jet angle vector for valve port inflow — Jet angle values for inflow

[21, 69, 69, 90, 90, 90] deg (default) | vector

Jet angle values for inflow through the valve. These values correspond to the values in the Opening distance vector for jet angle parameter. Use 90° as the last element in this vector so that the flow momentum force goes to zero. If the last element is not 90, the flow momentum force continues to be nonzero for any opening larger than the table range.

Dependencies

To enable this parameter, set Flow momentum force model to Based on tabulated jet angle.

Programmatic Use

Parameter: jet_angle_inflow_TLU

Jet angle vector for valve port outflow — Jet angle values for outflow

[21, 69, 69, 90, 90, 90] deg (default) | vector

Jet angle values for outflow through the valve. These values correspond to the values in the Opening distance vector for jet angle parameter. If the last element is not 90, the flow momentum force continues to be nonzero for any opening larger than the table range.

Dependencies

To enable this parameter, set Flow momentum force model to Based on tabulated jet angle.

Programmatic Use

Parameter: jet_angle_outflow_TLU

Plots

Metering area — Generate metering area plot

button

Use the Plot button to generate the metering area plot.

Jet angle — Generate jet angle plot

button

Use the Plot button to generate the jet angle plot. To generate a plot, you must set Flow momentum force model to Based on von Mises jet angle or Based on tabulated jet angle.

References

[1] Manring, Noah D. Hydraulic Control Systems. John Wiley & Sons, 2005.

[2] Merritt, Herbert E. Hydraulic Control Systems. John Wiley & Sons, 1967.

[3] von Mises, R., 1917. Berechnung von Ausfluß und uberfallzahlen. VDI, (22), pp. 469-474.

Extended Capabilities

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

Version History

Introduced in R2026b