FCSys.Species.N2.Gas

N₂ gas

Information

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

Package Content

Name	Description
Fixed	Fixed properties

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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 b_c = [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 (B_c) is set such that the specific entropy is 191.610 J/(mol·K) at 25 °C and p^o (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;