# NitrogenFluidProperties

Fluid properties for Nitrogen (N2)

Fluid properties for nitrogen are mainly calculated using the Span et al. equation of state (Span et al., 2000). This formulation uses density and temperature as the primary variables with which to calculate properties such as density, enthalpy and internal energy.

When used with the pressure and temperature interface, which is the case in the Porous Flow module, nitrogen properties are typically calculated by first calculating density iteratively for a given pressure and temperature. This density is then used to calculate the other properties, such as internal energy, directly.

Viscosity and thermal conductivity are calculated using the formulation presented in Lemmon and Jacobsen (2004).

Dissolution of nitrogen into water is calculated using Henry's law (IAPWS, 2004).

## Properties of nitrogen

Propertyvalue
Molar mass0.02801348 kg/mol
Critical temperature126.192 K
Critical pressure3.3958 MPa
Critical density313.3 kg/m
Triple point temperature63.151 K
Triple point pressure12.523 kPa

## Range of validity

The NitrogenFluidProperties UserObject is valid for:

• 63.151 K T 1000 K for p 2200 MPa

## Input Parameters

• allow_imperfect_jacobiansFalsetrue to allow unimplemented property derivative terms to be set to zero for the AD API

Default:False

C++ Type:bool

Options:

Description:true to allow unimplemented property derivative terms to be set to zero for the AD API

• execute_onTIMESTEP_ENDThe list of flag(s) indicating when this object should be executed, the available options include NONE, INITIAL, LINEAR, NONLINEAR, TIMESTEP_END, TIMESTEP_BEGIN, FINAL, CUSTOM.

Default:TIMESTEP_END

C++ Type:ExecFlagEnum

Options:NONE INITIAL LINEAR NONLINEAR TIMESTEP_END TIMESTEP_BEGIN FINAL CUSTOM

Description:The list of flag(s) indicating when this object should be executed, the available options include NONE, INITIAL, LINEAR, NONLINEAR, TIMESTEP_END, TIMESTEP_BEGIN, FINAL, CUSTOM.

### Optional Parameters

• control_tagsAdds user-defined labels for accessing object parameters via control logic.

C++ Type:std::vector

Options:

Description:Adds user-defined labels for accessing object parameters via control logic.

• enableTrueSet the enabled status of the MooseObject.

Default:True

C++ Type:bool

Options:

Description:Set the enabled status of the MooseObject.

• allow_duplicate_execution_on_initialFalseIn the case where this UserObject is depended upon by an initial condition, allow it to be executed twice during the initial setup (once before the IC and again after mesh adaptivity (if applicable).

Default:False

C++ Type:bool

Options:

Description:In the case where this UserObject is depended upon by an initial condition, allow it to be executed twice during the initial setup (once before the IC and again after mesh adaptivity (if applicable).

• force_preauxFalseForces the GeneralUserObject to be executed in PREAUX

Default:False

C++ Type:bool

Options:

Description:Forces the GeneralUserObject to be executed in PREAUX

• use_displaced_meshFalseWhether or not this object should use the displaced mesh for computation. Note that in the case this is true but no displacements are provided in the Mesh block the undisplaced mesh will still be used.

Default:False

C++ Type:bool

Options:

Description:Whether or not this object should use the displaced mesh for computation. Note that in the case this is true but no displacements are provided in the Mesh block the undisplaced mesh will still be used.

1. IAPWS. Guidelines on the Henry's constant and vapour liquid distribution constant for gases in H$_2$O and D$_2$O at high temperatures. Technical Report, IAPWS, 2004.[BibTeX]