Upgrading Hydraulic Models to Use Isothermal Liquid Blocks

Resources for converting models from the hydraulic domain to the isothermal liquid domain

Use the isothermal liquid domain to model hydraulic systems where the working fluid temperature remains constant during simulation. (since R2020a)

Upgrade your legacy hydraulic models to use the Isothermal Liquid library blocks.

Each of the hydraulic example models listed on this page has a matching isothermal liquid example model, listed under Isothermal Liquid Systems. You can open the models side by side to compare them, or try converting any of the hydraulic models and comparing the result to the corresponding isothermal liquid example model. For detailed, step-by-step examples of converting and cleaning up one of these models, see hydraulicToIsothermalLiquid.

Topics

Get Started With Model Conversion

Advantages of Using Isothermal Liquid Blocks
Blocks in the Isothermal Liquid library provide increased accuracy and numerical performance and are easier to use.
Upgrade Considerations When Converting Hydraulic to Isothermal Liquid Models
Learn about how to maintain the original model functionality after converting a model from hydraulic to isothermal liquid blocks by adjusting the blocks and block parameters.

Convert Your Model

How to Upgrade Hydraulic Models
Learn how to use the hydraulicToIsothermalLiquid conversion tool and review the results.
Upgrading Systems with Enabled Library Links, Model References, and Subsystem References
Preserve the links between files in models that contain hydraulic blocks from custom Simulink^® libraries, referenced models, or subsystems.
Upgrading Custom Hydraulic Blocks to Use the Isothermal Liquid Domain
Rewrite underlying code of custom hydraulic blocks to convert them to isothermal liquid domain.

Block Substitution Tables and Conversion Messages

Conversion Messages After Converting Hydraulic to Isothermal Liquid Models
Learn about warning messages in the HTML report and recommended actions when you upgrade your models using the hydraulicToIsothermalLiquid conversion tool.
Block Substitutions for Foundation Library Hydraulic Blocks
Learn about the block substitutions the hydraulicToIsothermalLiquid conversion tool makes for Simscape > Foundation Library > Hydraulic library blocks.

Functions

`hydraulicToIsothermalLiquid`	Upgrade hydraulic block diagram system to use isothermal liquid blocks (Since R2020a)
`hydraulicToIsothermalLiquidPostProcess`	Restore original file names and links after upgrading hydraulic block diagram systems to use isothermal liquid blocks (Since R2021a)

Simscape Blocks

Interface (H-IL)

Flow connection between hydraulic and isothermal liquid networks (Since R2020a)

Featured Examples

Hydraulic Actuator with Analog Position Controller

How the Foundation library can be used to model systems that span electrical, mechanical and hydraulic domains. In the model, a hydraulic system controls mechanical load position in response to a voltage reference demand. If the reference demand is zero, then the hydraulic actuator (and load) displacement is zero, and if the reference is +5 volts, then the displacement is 100mm.

Open Model

Hydraulic Actuator with Analog Position Controller and Dashboard Blocks

Use the Foundation library to model systems that span electrical, mechanical and hydraulic domains.

Open Model

Hydraulic Actuator with Digital Position Controller

A two-way valve acting in a closed-loop circuit together with a double-acting cylinder. The controller is represented as a continuous-time transfer function plus a transport delay. The delay allows for the computational time (one discrete time period) plus the zero-order hold (half a discrete time period) when implemented in discrete time. The model is configured for linearization so that a frequency response can be generated. To configure for faster desktop simulation, comment through the transport delay and increase the solver maximum step size.

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Hydraulic Actuator Configured for HIL Testing

A physical system model and controller configured for HIL testing. It is derived from example Hydraulic Actuator with Digital Position Controller, HydraulicActuatorWithDigitalPositionControllerHExample. The model has been configured for HIL testing by performing the following steps:

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Cavitation Cycle

How the fluid in a custom double acting cylinder can cavitate and recover. During the repeating cycle of oscillating pressure, the absolute pressure does not get below absolute zero as the bulk modulus of the homogeneous liquid-gas mixture decreases accordingly at low pressures.

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