Eddy Contact Micromixing Model Reference

The Eddy Contact Micromixing model [757] is numerically efficient, reasonably accurate, and easy to use for multiple reactions. It can be used for both steady and unsteady cases. This model is only available with the multicomponent liquid model, and requires turbulence modeling. It works with all turbulent models that are available for the EBU hybrid model.

Table 1. Eddy Contact Micromixing Model Reference
Theory	See Eddy Contact Micromixing.
Provided By	[physics continuum] > Models > Reacting Species Models
Example Node Path	Continua > Physics 1 > Models > Eddy Contact Micromixing
Requires	Material: Multi-Component Liquid Reaction Regime: Reacting Reacting Flow Models: Reacting Species Transport
Properties	Key properties are: Source Enabled Trigger, Begin, and Store Reaction Rates. See Eddy Contact Micromixing Properties.
Activates	Model Controls (child nodes)	Reactions. See Reactions.
	Materials	Specify the liquid materials under the Multi-Component Liquid model.

Eddy Contact Micromixing 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.

Store Reaction Rates

Provides the capability to post-process reaction rates, forward and backward (where applicable).

Activated Stores reaction rates during the simulation run and makes them available among scalar functions.
Deactivated Does not store reaction rates (default).

Reactions

Right-Click Actions

New Reaction: Creates a Reaction [n] sub-node.; See Reaction [n] Reference.

[reaction]

The defined reaction Type can only be Eddy Contact.

Reactants: Defines the reactant components of the Eddy Contact Micromixing reaction.

Products: Defines the product components of the Eddy Contact Micromixing reaction.

Properties > Micromixing Timescale

Allows you to select the method for calculating the micromixing timescale.


Select Method	Corresponding Method Node/Sub-Node
Classical Scalar Dissipation Selects the Classical Scalar Mixing method (considers the high-Schmidt number effect for liquids) [758].	Dissipation Coefficient The mixing coefficient $A$ , in Eqn. (3488).
Kolmogorov Selects the Kolmogorov Method (corresponds to Engulfment type of mixing). See Source Term Definition.	Mixing Coefficient The mixing coefficient $A$ , inEqn. (3487).
No Micromixing (Kinetics Only) Selects the assumption that the reaction rate is dictated solely by finite-rate chemical kinetics.	None.
User Micromixing Selects the User Defined method, allowing you to work with a user-defined field function.	User Micromixing TimeScale Specifies the user defined micromixing timescale.

Properties > Reaction Coefficient

Defines the reaction rate method for Eddy Contact Micromixing reaction. Following are the methods that can be applied:


Method	Corresponding Method Node/Sub-Node
Arrhenius Coefficients The Arrhenius reaction parameters are used to calculate chemical reaction rates from finite-rate kinetics.	Arrhenius Coefficients Pre-exponent Defines the pre-exponential factor, $A$ , in Eqn. (3365).
User Reaction Coefficient The user reaction coefficient allows you to specify custom reaction coefficients.	User Reaction Coefficient Specifies the custom reaction coefficients. After combining with species concentration contributions, the units for the corresponding reaction rates are Quantity/Length³-Time. See Eqn. (3364).