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Isothermal Liquid Models

Basic isothermal liquid blocks and modeling techniques

Isothermal Liquid libraries contain blocks for the isothermal liquid domain, organized into elements, sources, and sensors. Connect these blocks together just as you would assemble a physical system. Use these blocks, along with the blocks from other Foundation libraries and the add-on products, to model multidomain physical systems.

The Utilities library contains the Isothermal Liquid Properties (IL) block, which lets you specify the properties of the working fluid in the connected loop. The temperature of the working fluid is assumed to be constant during simulation time. To model thermodynamic effects, use the blocks from the Thermal Liquid library. For a complete list of domains available for modeling fluid systems, see Fluid System Modeling.

The Isothermal Liquid domain and libraries provide an alternative to the Hydraulic domain and libraries. Starting in R2020a, use the Isothermal Liquid blocks for modeling hydraulic systems where the working fluid temperature remains constant during simulation. For information on the upgrade process for existing hydraulic models, see Upgrading Hydraulic Models to Use Isothermal Liquid Blocks.


  • Elements
    Isothermal liquid building blocks, such as chambers, reservoirs, local restrictions, hydro-mechanical converters
  • Sensors
    Isothermal liquid flow rate and pressure sensor blocks
  • Sources
    Isothermal liquid flow rate and pressure source blocks
  • Utilities
    Basic isothermal liquid environment blocks that specify fluid properties, hydraulic-to-isothermal-liquid conversion utility
  • Isothermal Liquid Systems
    Featured examples of isothermal liquid hydraulic systems
  • Upgrading Hydraulic Models to Use Isothermal Liquid Blocks
    Resources for converting models from the hydraulic domain to the isothermal liquid domain