Plasma Model Reference Topic

Table 1. Coupled Plasma Electron Model Reference
Theory	See Cold, Non-Thermal Plasma and Reacting Flow Plasma.
Provided By	[physics continuum] > Models > Plasma
Example Node Path	Continua > Physics 1 > Models > Coupled Plasma Electron Model
Requires	Space: any Material: Gas or Multi-Component Gas Optional Models: Plasma
Properties	See Coupled Plasma Electron Model properties.
Activates	Model Controls (child nodes)	e-
	Material Properties	Charge Number, Mobility, Molecular Diffusivity, Molecular Weight. Also, for the [gas component], the Elastic Electron Collisional Cross Section Material Property is available to set.
	Initial Conditions	Electron Number Density, Electron Temperature. See Initial Conditions.
	Boundary Inputs	Electron Number Density Specification, Electron Thermal Specification. See Boundary Settings.
	Region Inputs	Electron Energy Density Source Option, Electron Source Option. See Region Settings.
	Solvers	Coupled Plasma Electron. See Solvers.
	Monitors	Electron Density, Electron Energy
	Field Functions	Charged Species Mobility of Electron Elastic Electron Collisional Cross Section Electron Elastic Collision Energy Source Electron Energy Density Electron Number Density Electron Ohmic Energy Source Electron Temperature Molecular Diffusivity of Electron See Field Functions.

Coupled Plasma Electron Model Properties

Transport

Allows you to specify how the electric potential is coupled with the electrons.

Electrons < > Electric Potential This selection is appropriate for modeling most plasma setups.
Electric Potential > Electrons
Electrons > Electric Potential
No Electric Potential Coupling

Secondary Gradients

Neglect or include the boundary secondary gradients for diffusion and/or the interior secondary gradients at mesh faces. See Omitting Secondary Gradients.

On
Include both secondary gradients.
Off
Exclude both secondary gradients.
Interior Only
Include the interior secondary gradients only.
Boundaries Only
Include the boundary secondary gradients only.

Initial Conditions

Electron Number Density: Sets the electron number density $n_{e}$ as a scalar profile.
Electron Temperature: Sets the temperature $T_{e}$ as a scalar profile.

Boundary Settings

Wall Boundaries

Electron Number Density Specification

Allows you to choose how the number density,

n_{e}

, of the electrons is specified at the boundary.

Method	Corresponding Physics Value Nodes
Impermeable Specifies that the boundary is impermeable to electrons – which is essentially a vanishing flux that is provided at the boundary.	None
Specified Flux Allows you to specify the electron number density as an influx or outflux of electrons. Also provides the physics condition, Wall Electron Number Density Flux Derivitave Option.	Electron Flux Specifies the electron flux, $Γ_{e}$ , as a scalar profile.
Specified Value Sets the electron number density to the specified value.	Electron Number Density Specifies the electron number density as a scalar profile.

Wall Electron Number Density Flux Derivitave Option

Allows you to specify an electron number density flux derivative.

Method	Corresponding Physics Value Nodes
None	None
Specified	Electron Flux Derivative Specifies the electron flux derivative, ${Γ^{'}}_{e}$ , as a scalar profile.

Electron Thermal Specification

Allows you to choose how the thermal energy of the electrons is specified.

Method	Corresponding Physics Value Nodes
Specified Electron Temperature Sets the electron temperature $T_{e}$ .	Electron Temperature Specifies the electron temperature as a scalar profile.
Specified Electron Energy Flux Allows you to specify the thermal energy of the electrons as an energy flux. Also provides the physics condition, Wall Electron Energy Density Flux Derivative Option.	Electron Energy Flux Specifies the electron energy flux, $Γ_{\in}$ , as a scalar profile.

Wall Electron Energy Density Flux Derivitave Option

Allows you to specify an electron energy density flux derivative.

Method	Corresponding Physics Value Nodes
None	None
Specified	Electron Energy Flux Derivative Specifies the electron energy flux derivative, ${Γ^{'}}_{e}$ , as a scalar profile.

Inflow and Outflow Boundaries

Electron Number Density: Specifies the electron number density, $n_{e}$ , at inflow and outflow boundaries as a scalar profile.
Electron Temperature: Specifies the electron temperature, $T_{e}$ , at inflow and outflow boundaries as a scalar profile.

Region Settings

Applies to fluid regions.

Electron Energy Density Source Option

Method	Corresponding Physics Value Nodes
Electron Energy Source When activated, allows you to specify the electron energy density source term and its derivative.	Electron Energy Source Specifies the electron energy density source term, $S_{\in, u s r}$ as a scalar profile. Electron Energy Source Derivative Specifies the derivative of the electron energy density source term.

Electron Source Option

Method	Corresponding Physics Value Nodes
Electron Source When activated, allows you to specify the electron number density source term and its derivative.	Electron Source Specifies the electron number density source term, $S_{e, u s r}$ , as a scalar profile. The electrons are assumed to be cold unless an electron energy source is added. Electron Source Derivative Allows you to specify the derivative of the electron number density source term.

Coupled Plasma Electron Solver Properties

Begin: Specifies the iteration or time-step after which the reactions are activated. During previous iterations or time-steps, reactions are deactivated. This feature is useful when modeling significant flow as you can deactivate reactions until a flow solution is found.
Solver Frozen: When On, the solver does not update any quantity during an iteration. It is Off by default. This is a debugging option that can result in non-recoverable errors and wrong solutions due to missing storage. See Finite Volume Solvers Reference for details.
Reconstruction Frozen: When On, Simcenter STAR-CCM+ does not update reconstruction gradients with each iteration, but rather uses gradients from the last iteration in which they were updated. Activate Temporary Storage Retained in conjunction with this property. This property is Off by default.
Reconstruction Zeroed: When On, the solver sets reconstruction gradients to zero at the next iteration. This action means that face values used for upwinding (Eqn. (905)) and for computing cell gradients (Eqn. (917) and Eqn. (918)) become first-order estimates. This property is Off by default. If you turn this property Off after having it On, the solver recomputes the gradients on the next iteration.
Temporary Storage Retained: When On, Simcenter STAR-CCM+ retains additional field data that the solver generates during an iteration. The particular data retained depends on the solver, and becomes available as field functions during subsequent iterations. Off by default.

Field Functions

Charged Species Mobility of Electron: Mobility of electrons, $μ_{e}$
Elastic Electron Collisional Cross Section: Elastic collision momentum transfer cross-section $σ_{ζ e}$ which is used to calculate the collision frequency.
Electron Elastic Collision Energy Source: Electron elastic collision energy source term, $S_{e l}$ in Eqn. (4193).
Electron Energy Density: Electron energy density, $\in_{e}$
Electron Number Density: Electron number density, $n_{e}$
Electron Ohmic Energy Source: Electron Ohmic heating energy source term, $S_{Ω}$ in Eqn. (4193).
Electron Temperature: Electron temperature, $T_{e}$
Molecular Diffusivity of Electron: Molecular diffusivity of electrons, $D_{e}$