## FCSys.Species.N2.Gas

N2 gas

### Information

Extends from Modelica.Icons.Package (Icon for standard packages).

### Package Content

Name | Description
--- | ---
Fixed | Fixed properties

## FCSys.Species.N2.Gas.Fixed

Fixed properties

### Information

Assumptions:

1. The generalized resistivities (η, θ) are fixed (e.g., independent of thermodynamic state).
2. Ideal gas
3. Fixed specific heat capacity (independent of temperature)

The default specific heat capacity (via bc = `[1.041e3*U.J*Data.m/(U.kg*U.K)]`) and resistivities (η = `1/(17.82e-6*U.Pa*U.s)` and θ = `U.m*U.K/(25.9e-3*U.W))`) are based on data of gas at 1 atm and 300 K from Incropera and DeWitt [Incropera2002, p. 920]. The integration offset for specific entropy (Bc) is set such that the specific entropy is 191.610 J/(mol·K) at 25 °C and po (1 bar). This is the value from Table B in [McBride2002]. Additional data is listed in Table 1.

Table 1: Properties of N2 gas at 1 atm [Incropera2002, p. 920]
T `/U.K` | cp`*U.kg*U.K /(U.J*Data.m)` | η`*U.Pa*U.s` | θ`*U.W /(U.m*U.K)`
--- | --- | --- | ---
100 | 1.070e3 | 1/68.8e-7 | 1/9.58e-3
150 | 1.050e3 | 1/100.6e-7 | 1/13.9e-3
200 | 1.043e3 | 1/129.2e-7 | 1/18.3e-3
250 | 1.042e3 | 1/154.9e-7 | 1/22.2e-3
300 | 1.041e3 | 1/178.2e-7 | 1/25.9e-3
350 | 1.042e3 | 1/200.0e-7 | 1/29.3e-3
400 | 1.045e3 | 1/220.4e-7 | 1/32.7e-3
450 | 1.050e3 | 1/239.6e-7 | 1/35.8e-3
500 | 1.056e3 | 1/257.7e-7 | 1/38.9e-3
550 | 1.065e3 | 1/274.7e-7 | 1/41.7e-3
600 | 1.075e3 | 1/290.8e-7 | 1/44.6e-3
700 | 1.098e3 | 1/320.1e-7 | 1/49.9e-3
800 | 1.220e3 [sic] | 1/349.1e-7 | 1/54.8e-3
900 | 1.146e3 | 1/375.3e-7 | 1/59.7e-3
1000 | 1.167e3 | 1/399.9e-7 | 1/64.7e-3
1100 | 1.187e3 | 1/423.2e-7 | 1/70.0e-3
1200 | 1.204e3 | 1/445.3e-7 | 1/75.8e-3
1300 | 1.219e3 | 1/466.2e-7 | 1/81.0e-3

The fluidity of air at 15 °C and 1 atm is given by η = `1/(17.8e-6*U.Pa*U.s)` (http://en.wikipedia.org/wiki/Viscosity).

For more information, please see the Species model.

Extends from Fluid (Base model for a fluid species).

### Parameters

Type | Name | Default | Description
--- | --- | --- | ---
Integer | n_inter | 0 | Number of exchange connections with other phases
Material properties
replaceable package Data | FCSys.Characteristics.N2.Gas… | Characteristic data
Independence factors
NumberAbsolute | k_intra_Phi[n_intra, n_trans] | ones(n_intra, n_trans) | For translational exchange among species within the phase [1]
NumberAbsolute | k_intra_Q[n_intra] | ones(n_intra) | For thermal exchange among species within the phase [1]
Initialization
Velocity | phi.start[n_trans] | 0 | Velocity [L/T]
Current | I.start[n_trans] | 0 | Current [N/T]
Velocity | phi_boundaries.start[n_trans, Side] | 0 | Normal velocities at the boundaries [L/T]
Force | f.start[n_trans] | 0 | Total normal translational force on pairs of boundaries [L.M/T2]
Force | minusDeltaf.start[n_trans] | 0 | Dynamic and nonequilibrium compression forces [L.M/T2]
Geometry
Length | kL[:] | L[cartTrans] | Effective transport length [L]
Initialization
Init | initMaterial | Init.pressure | Method of initializing the material state
Init | initEnergy | Init.temperature | Method of initializing the thermal state
Amount | N_IC |  | Initial amount of material [N]
Density | rho_IC |  | Initial density [N/L3]
Volume | V_IC |  | Initial volume [L3]
PressureAbsolute | p_IC | environment.p_dry - environm… | Initial pressure [M/(L.T2)]
TemperatureAbsolute | T_IC |  | Initial temperature [L2.M/(N.T2)]
Potential | h_IC |  | Initial specific enthalpy [L2.M/(N.T2)]
Potential | g_IC |  | Initial Gibbs potential [L2.M/(N.T2)]
Assumptions
Integer | n_trans | 1 | Number of transport axes
Integer | n_chem | 0 | Number of reaction and phase change processes
Formulation of the conservation equations
ConsThermo | consMaterial | ConsThermo.dynamic | Material
Boolean | consRot | false | Conserve rotational momentum
ConsTrans | consTransX | ConsTrans.dynamic | X-axis translational momentum
ConsTrans | consTransY | ConsTrans.dynamic | Y-axis translational momentum
ConsTrans | consTransZ | ConsTrans.dynamic | Z-axis translational momentum
ConsThermo | consEnergy | ConsThermo.dynamic | Energy
Axes with upstream discretization
Boolean | upstreamX | true | X
Boolean | upstreamY | true | Y
Boolean | upstreamZ | true | Z
Flow conditions
Boolean | approxVelocity | true | Calculate normal boundary velocities assuming uniform density
NumberAbsolute | Nu_Phi[Axis] | {4,4,4} | Translational Nusselt numbers [1]
NumberAbsolute | Nu_Q | 1 | Thermal Nusselt number [1]

### Connectors

Type | Name | Description
--- | --- | ---
Intra | intra[n_intra] | Connectors to exchange translational momentum and energy within the phase
Inter | inter[n_inter] | Connectors to exchange translational momentum and energy with all other species
Dalton | dalton | Connector for additivity of pressure
Boundary | boundaries[n_trans, Side] | Connectors for transport
Chemical | chemical[n_chem] | Connector for reactions and phase change
Material properties
replaceable package Data | Characteristic data

### Modelica definition

    model Fixed "Fixed properties"
      import FCSys.Utilities.Polynomial;

      extends Fluid(
        redeclare replaceable package Data = FCSys.Characteristics.N2.Gas (
            b_v=[1],
            n_v={-1,0},
            n_c=0,
            T_lim_c={0,Modelica.Constants.inf},
            b_c=[1041*U.J*Data.m/(U.kg*U.K)],
            B_c=[Data.Deltah0_f - (1041*U.J*Data.m/U.kg)*298.15, 191.610*U.J/(U.mol*
                U.K) - (1041*U.J*Data.m/(U.kg*U.K))*log(298.15*U.K)]),
        redeclare parameter Q.Mobility mu=Data.mu(),
        redeclare parameter Q.TimeAbsolute nu=Data.nu(),
        redeclare parameter Q.Continuity zeta=Data.zeta(),
        redeclare parameter Q.Fluidity eta=1/(17.82e-6*U.Pa*U.s),
        redeclare parameter Q.ResistivityThermal theta=U.m*U.K/(25.9e-3*U.W),
        final tauprime,
        final N0,
        n_chem=0,
        p_IC=environment.p_dry - environment.p_O2);

      // See the documentation for a table of values.

    end Fixed;