adding Isoentropic efficiency to mass flow rate(2P) block

I wish to add a parameter "iso-entropic efficiency" to the block "controlled mass flow rate (2P). Kindly guide me to what changes/additions i need to make to the source code of the respective block.

component controlled_mass_flow_source
% Controlled Mass Flow Rate Source (2P)
% This block represents an ideal mechanical energy source in a two-phase
% fluid network that can maintain a controlled mass flow rate regardless of
% the pressure differential. There is no flow resistance and no heat
% exchange with the environment. The mass flow rate is set by the physical
% signal port M [kg/s]. A positive value causes fluid to flow from port A
% to port B.

% Copyright 2013-2017 The MathWorks, Inc.

nodes
    A = foundation.two_phase_fluid.two_phase_fluid; % A:left
    B = foundation.two_phase_fluid.two_phase_fluid; % B:right
end

inputs
    % Mass flow rate
    M = {0, 'kg/s'}; % M:left
end

parameters
    power_spec = foundation.enum.power_spec.isentropic; % Power added
    %                                                     1 - isentropic
    %                                                     0 - none
    area_A = {0.01, 'm^2'}; % Cross-sectional area at port A
    area_B = {0.01, 'm^2'}; % Cross-sectional area at port B
end

% Parameter checks
equations
    assert(area_A > 0)
    assert(area_B > 0)
end

variables (Access=protected)
    mdot_A = {0, 'kg/s'}; % Mass flow rate into port A
    mdot_B = {0, 'kg/s'}; % Mass flow rate into port B
    Phi_A  = {0, 'kW'  }; % Energy flow rate into port A
    Phi_B  = {0, 'kW'  }; % Energy flow rate into port B
    power  = {0, 'kW'  }; % Power added to fluid flow
end

branches
    mdot_A : A.mdot -> *;
    mdot_B : B.mdot -> *;
    Phi_A  : A.Phi  -> *;
    Phi_B  : B.Phi  -> *;
end

if power_spec == foundation.enum.power_spec.isentropic

    variables (Access=private, ExternalAccess=none)
        u_in_A  = {1500, 'kJ/kg'}; % Specific internal energy for inflow at port A
        u_in_B  = {1500, 'kJ/kg'}; % Specific internal energy for inflow at port B
        u_out_A = {1500, 'kJ/kg'}; % Specific internal energy for outflow at port A
        u_out_B = {1500, 'kJ/kg'}; % Specific internal energy for outflow at port B
    end

    equations
        let
            % Compute change in specific entropy
            [Ds_AB, ht_in_A, ht_out_B] = foundation.two_phase_fluid.sources.isentropic_relation( ...
                A.p, B.p, u_in_A, u_out_B, mdot_A, area_A, area_B, ...
                A.u_min, A.u_max, A.unorm_TLU, A.p_TLU, A.v_TLU, A.s_TLU, A.u_sat_liq_TLU, A.u_sat_vap_TLU);

            [Ds_BA, ht_in_B, ht_out_A] = foundation.two_phase_fluid.sources.isentropic_relation( ...
                B.p, A.p, u_in_B, u_out_A, mdot_B, area_B, area_A, ...
                A.u_min, A.u_max, A.unorm_TLU, A.p_TLU, A.v_TLU, A.s_TLU, A.u_sat_liq_TLU, A.u_sat_vap_TLU);
        in
            % Power added to the flow by the source
            if ge(M, 0)
                power == mdot_A*(ht_out_B - ht_in_A);
            else
                power == mdot_B*(ht_out_A - ht_in_B);
            end

            % Isentropic relation between inflow and outflow
            Ds_AB == 0;
            Ds_BA == 0;

            % Specific total enthalpy for outflow
            ht_out_A == convection_A.ht_I;
            ht_out_B == convection_B.ht_I;
        end
    end

else % power_spec == foundation.enum.power_spec.none

    equations
        power == 0;
    end

end

equations
    % Commanded mass flow rate
    mdot_A == M;

    % Mass balance
    mdot_A + mdot_B == 0;

    % Energy balance
    Phi_A + Phi_B + power == 0;

    % Run-time variable checks
    assert(A.p >= A.p_min, message('physmod:simscape:library:two_phase_fluid:PressureMinValid', 'A'))
    assert(A.p <= A.p_max, message('physmod:simscape:library:two_phase_fluid:PressureMaxValid', 'A'))
    assert(A.u >= A.u_min, message('physmod:simscape:library:two_phase_fluid:InternalEnergyMinValid', 'A'))
    assert(A.u <= A.u_max, message('physmod:simscape:library:two_phase_fluid:InternalEnergyMaxValid', 'A'))
    assert(B.p >= B.p_min, message('physmod:simscape:library:two_phase_fluid:PressureMinValid', 'B'))
    assert(B.p <= B.p_max, message('physmod:simscape:library:two_phase_fluid:PressureMaxValid', 'B'))
    assert(B.u >= B.u_min, message('physmod:simscape:library:two_phase_fluid:InternalEnergyMinValid', 'B'))
    assert(B.u <= B.u_max, message('physmod:simscape:library:two_phase_fluid:InternalEnergyMaxValid', 'B'))

    % Equate variables for internal components that calculate energy convection at ports A and B
    convection_A.mdot == mdot_A;
    convection_A.Phi  == Phi_A;
    convection_B.mdot == mdot_B;
    convection_B.Phi  == Phi_B;

    convection_A.ht_I == convection_B.ht_I;
end

% Internal components that calculate energy convection at ports A and B
components (ExternalAccess=none)
    convection_A = foundation.two_phase_fluid.port_convection(flow_area = area_A, length_scale = sqrt(4*area_A/pi));
    convection_B = foundation.two_phase_fluid.port_convection(flow_area = area_B, length_scale = sqrt(4*area_B/pi));
end

connections
    connect(A, convection_A.port)
    connect(B, convection_B.port)
end

end

Answer 1

[Kresten]

Add an isentropic efficiency parameter:

parameters
    power_spec = foundation.enum.power_spec.isentropic; % Power added
    %                                                     1 - isentropic
    %                                                     0 - none
    isentropic_efficiency = {1.00, 'J/J'}; % Isentropic efficiency 
    area_A = {0.01, 'm^2'}; % Cross-sectional area at port A
    area_B = {0.01, 'm^2'}; % Cross-sectional area at port B

end

% Parameter checks
equations
    assert(area_A > 0)
    assert(area_B > 0)
    assert(isentropic_efficiency <= 1.0)
    assert(isentropic_efficiency >  0.0)
end

Then divide the power added by the identropic efficiency, like this:

 % Power added to the flow by the source.
if ge(V, 0)
    power == mdot_A*(ht_out_B - ht_in_A)/isentropic_efficiency;
else
    power == mdot_B*(ht_out_A - ht_in_B)/isentropic_efficiency;
end

If you need variable isentropic efficiency you should create an input instead of a parameter.