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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 domain will be removed in a future release. Use the Isothermal Liquid 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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