Two-Phase Fluid Domain

To view the complete domain source file, at the MATLAB^® Command prompt, type:

open([matlabroot '/toolbox/physmod/simscape/library/m/+foundation/+two_phase_fluid/two_phase_fluid.ssc'])

Abbreviated two-phase fluid domain declaration is shown below, with intermediate lookup table values omitted for readability.

domain two_phase_fluid
% Two-Phase Fluid Domain

% Copyright 2013-2018 The MathWorks, Inc.

parameters
    p_min  = {1e-3,     'MPa'  }; % Minimum valid pressure
    p_max  = {95,       'MPa'  }; % Maximum valid pressure
    u_min  = {0,        'kJ/kg'}; % Minimum valid specific internal energy
    u_max  = {4000,     'kJ/kg'}; % Maximum valid specific internal energy
    p_crit = {22.0640,  'MPa'  }; % Critical pressure
    p_atm  = {0.101325, 'MPa'  }; % Atmospheric pressure
    properties_range_check = simscape.enum.assert.action.error; % Pressure and specific internal energy outside valid range
    %                                                             0 - none
    %                                                             1 - warn
    %                                                             2 - error
    q_rev  = {0.01,     'Pa'   }; % Dynamic pressure threshold for flow reversal

    transition_range = {0.1, '1'}; % Range in vapor quality for smoothing of density partial derivatives

    % Default fluid property tables for water
    % Rows of the tables correspond to the normalized internal energy vector
    % Columns of the tables correspond to the pressure vector

    unorm_TLU = {[
        -1
        -0.958333333333333
        ...
        1.95833333333333
        2
        ], '1'}; % Normalized internal energy vector

    unorm_liq_TLU = {[
        -1
        -0.958333333333333
	...
        -0.0416666666666666
        0
        ], '1'}; % Normalized liquid internal energy vector

    unorm_vap_TLU = {[
        1
        1.04166666666667
	...
        1.95833333333333
        2
        ], '1'}; % Normalized vapor internal energy vector

    unorm_mix_TLU = {[
        0
        0.0204081632653061
	...
        0.979591836734694
        1
        ], '1'}; % Normalized mixture internal energy vector

    p_TLU = {[
        0.00100000000000000
        ...
        95.0000000000000
        ], 'MPa' }; % Pressure vector

    v_TLU = {[
        0.00100020732544948	... 	0.00646806895821810
        ], 'm^3/kg'}; % Specific volume table

    s_TLU = {[
        -7.05045840376749e-13	... 	6.81117017439253
        ], 'kJ/kg/K'}; % Specific entropy table

    T_TLU = {[
        273.159998291077	...	1348.81511704704
        ], 'K'}; % Temperature table

    nu_TLU = {[
        1.79172848157620	...	0.361552941837863
	], 'mm^2/s'}; % Kinematic viscosity table

    k_TLU = {[
        0.555598831086800	...	0.250538481070411
        ], 'W/(m*K)'}; % Thermal conductivity table

    Pr_TLU = {[
        13.6057970740934	...	0.671580102714643
        ], '1' };  % Prandtl number table

    DrhoDp_liq_TLU = {[
        0.509755264394891	...	1.80807388692342
	], 'kg/m^3/MPa'}; % Partial derivative of liquid density with pressure
			  % at constant specific internal energy table

    DrhoDp_vap_TLU = {[
        7.36831747174794	...	1.45923555583730
	], 'kg/m^3/MPa'}; % Partial derivative of vapor density with pressure
			  % at constant specific internal energy table

    DrhoDp_mix_TLU = {[
        1350.39031864440	...	1.80807388692342
	], 'kg/m^3/MPa'}; % Partial derivative of mixture density with pressure
			  % at constant specific internal energy table

    DrhoDu_liq_TLU = {[
        0.0160937306771423	...	-0.350392782066966
	], 'kg^2/m^3/kJ'}; % Partial derivative of liquid density with specific internal energy
			   % at constant pressure table
    DrhoDu_vap_TLU = {[
        -1.79894990819782e-05	...	-0.0610611856834271
	], 'kg^2/m^3/kJ'}; % Partial derivative of vapor density with specific internal energy
			   % at constant pressure table

    DrhoDu_mix_TLU = {[
        -0.0137995431136761	...	-0.350392782066966
	], 'kg^2/m^3/kJ'}; % Partial derivative of mixture density with specific internal energy
			   % at constant pressure table

    u_sat_liq_TLU = {[
        29.2976389515495
	...
    	2242.74587564859
        ], 'kJ/kg'}; % Saturated liquid specific internal energy vector

    u_sat_vap_TLU = {[
        2384.48887142334
	...
	2242.74587564859
        ], 'kJ/kg'}; % Saturated vapor specific internal energy vector

end

variables
    p = { 0.1,  'MPa'   };  % Pressure
    u = { 1500, 'kJ/kg' };  % Specific internal energy
end

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

end

The domain declaration contains the following variables and parameters:

Across variable p (absolute pressure), in MPa
Through variable mdot (mass flow rate), in kg/s
Across variable u (specific internal energy), in kJ/kg
Through variable Phi (energy flow rate), in kW
Parameter p_min, defining the minimum allowable pressure
Parameter p_max, defining the maximum allowable pressure
Parameter u_min, defining the minimum allowable specific internal energy
Parameter u_max, defining the maximum allowable specific internal energy
Parameter p_crit, defining the critical pressure
Parameter p_atm, defining the atmospheric pressure
Parameter q_rev, defining the dynamic pressure threshold for flow reversal

It also contains lookup table data, declared as domain parameters, for the following fluid properties:

Normalized internal energy vector
Normalized liquid internal energy vector
Normalized vapor internal energy vector
Normalized mixture internal energy vector
Pressure vector
Specific volume table
Specific entropy table
Temperature table
Kinematic viscosity table
Thermal conductivity table
Prandtl number table
Partial derivative of liquid density with pressure at constant specific internal energy table
Partial derivative of vapor density with pressure at constant specific internal energy table
Partial derivative of mixture density with pressure at constant specific internal energy table
Partial derivative of liquid density with specific internal energy at constant pressure table
Partial derivative of vapor density with specific internal energy at constant pressure table
Partial derivative of mixture density with specific internal energy at constant pressure table
Saturated liquid specific internal energy vector
Saturated vapor specific internal energy vector

These parameter declarations propagate to the components connected to the Two-Phase Fluid domain, and therefore you can use them in the tablelookup function in the component equations. In particular, the two-phase fluid blocks in the Foundation library use these lookup tables for interpolation purposes.

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

foundation.two_phase_fluid.two_phase_fluid

Two-Phase Fluid Domain

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