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Hydraulic Domain


Isothermal liquid domain, introduced in R2020a, provides a more robust and flexible way of modeling isothermal hydraulic systems.

Hydraulic library will be removed in a future release. Use the Isothermal Liquid library and domain to model hydraulic systems where the working fluid temperature remains constant during simulation.

The hydraulic domain declaration is shown below.

domain hydraulic
% Hydraulic Domain

% Copyright 2005-2013 The MathWorks, Inc.

    density       = { 850   , 'kg/m^3' }; % Fluid density
    viscosity_kin = { 18e-6 , 'm^2/s'  }; % Kinematic viscosity
    bulk          = { 0.8e9 , 'Pa'     }; % Bulk modulus at atm. pressure and no gas
    alpha         = { 0.005 , '1'      }; % Relative amount of trapped air

    p = { 0 , 'Pa' };

  variables(Balancing = true)
    q = { 0 , 'm^3/s' };


It contains the following variables and parameters:

  • Across variable p (gauge pressure), in Pa

  • Through variable q (volumetric flow rate), in m^3/s

  • Parameter density, specifying the default fluid density

  • Parameter viscosity_kin, specifying the default kinematic viscosity

  • Parameter bulk, specifying the default fluid bulk modulus at atmospheric pressure and no gas

  • Parameter alpha, specifying the default relative amount of trapped air in the fluid

To refer to this domain in your custom component declarations, use the following syntax:


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