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Isothermal Liquid Domain

The isothermal liquid domain declaration is shown below.

domain isothermal_liquid
% Isothermal Liquid Domain

% Copyright 2019 The MathWorks, Inc.

parameters
    bulk_modulus_model    = foundation.enum.bulk_modulus_model.const; % Isothermal bulk modulus model
    %                                                                   1 - const
    %                                                                   2 - linear
    air_dissolution_model = simscape.enum.onoff.off; % Air dissolution model
    %                                                  1 - on
    %                                                  0 - off
    rho_L_atm             = {998.21,    'kg/m^3'}; % Liquid density at atmospheric pressure (no entrained air)
    beta_L_atm            = {2.1791e9,  'Pa'    }; % Liquid isothermal bulk modulus at atmospheric pressure (no entrained air)
    beta_gain             = {6,         '1'     }; % Isothermal bulk modulus vs. pressure increase gain
    nu_atm                = {1.0034e-6, 'm^2/s' }; % Kinematic viscosity at atmospheric pressure
    air_fraction          = {0 ,        '1'     }; % Volumetric fraction of air that is entrained at atmospheric pressure
    rho_g_atm             = {1.225,     'kg/m^3'}; % Gas (air) density at atmospheric condition
    polytropic_index      = {1.0,       '1'     }; % Air polytropic index
    p_atm                 = {0.101325,  'MPa'   }; % Atmospheric pressure
    p_crit                = {3,         'MPa'   }; % Pressure at which all entrained air is dissolved
    p_min                 = {0.1,       'Pa'    }; % Minimum valid pressure
end

variables
    p = {0.1, 'MPa'}; % Pressure
end

variables (Balancing = true)
    mdot = {0, 'kg/s'}; % Mass flow rate
end

end

It contains the following variables and parameters:

  • Across variable p (absolute pressure), in MPa

  • Through variable mdot (mass flow rate), in kg/s

  • Enumerated parameter bulk_modulus_model, defining the bulk modulus parametrization, with two values:

    • 0 — Bulk modulus is constant

    • 1 — Bulk modulus is a function of pressure

  • Enumerated parameter air_dissolution_model, defining the entrained air parametrization, with two values:

    • 0 — Entrained air is constant

    • 1 — Entrained air is a function of pressure

  • Parameter rho_L_atm, defining the liquid density at atmospheric pressure, with zero entrained air

  • Parameter beta_L_atm, defining the liquid isothermal bulk modulus at atmospheric pressure, with zero entrained air

  • Parameter beta_gain, defining the ratio of bulk modulus to pressure increase, for when the bulk modulus is a function of pressure

  • Parameter nu_atm, defining the kinematic viscosity at atmospheric pressure

  • Parameter air_fraction, defining the volumetric fraction of air that is entrained at atmospheric pressure

  • Parameter rho_g_atm, defining the air density at atmospheric condition

  • Parameter polytropic_index, defining the air polytropic index

  • Parameter p_atm, defining the atmospheric pressure

  • Parameter p_crit, defining the pressure at which all entrained air is dissolved, for when the amount of entrained air is a function of pressure

  • Parameter p_min, defining the minimum valid pressure

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

foundation.isothermal_liquid.isothermal_liquid