Particle Reaction¶

Introduction¶

Reactions can be defined to occur within a particle. The below diagram shows how on-particle reactions interact with the surrounding scalar fields and custom particle variables.

Scalar coupling is first defined on the particle zone. This defines how the scalar is transferred into and out of the particle.

The scalar amount (defined in moles or \(m^3\)) in the particle can then be used in an on-particle reaction.

../../../_images/on-particle-reaction-diagram.png

This feature is used in combination with:

Fluid Reaction – Defines a scalar field in the surrounding fluid.
Miscible Scalar – Defines a miscible scalar field.
Scalar Coupling and Thermal Coupling – Defines how a scalar field transfers into and out of a particle.
Particle Variable – Defines a custom variable that only lives on a particle.
Particle Scalar – Defines a reaction species.

Property Grid¶

Intraparticle Reaction UDF

mol/s, g/s, or none | This UDF defines intraparticle reactions between species inside a particle. The number of output variables matches the total number of aqueous and particle scalar fields in the model. The output variables are named rate_{scalar}, where {scalar} is the dynamic name of the coupled scalar field, and rate_{pvs_p}, where {pvs_p} is the dynamic name of the particle species. Each output is a floating-point value representing the reaction rate.

Rates can be specified for all particle scalars, as well as species coupled to the scalar field. The interspecies reaction rate must have units compatible with those defined for the interparticle species concentration. Positive values indicate species production, while negative values indicate species consumption.

If a thermal field is present and the heat of reaction is enabled, an additional QDot output becomes available. Positive QDot values imply exothermic reactions, whereas negative values indicate endothermic reactions.

This is a particle-based local UDF, calculated on a particle-by-particle basis using the local particle/fluid properties.

Download Sample File: Injection

Integration

This setting defines which algorithm will be used to numerically integrate the reaction kinetics.

Euler (1st Order)

Runge-Kutta (4th Order)

Rosenbrock (Implicit)

Particle Reaction Toolbar¶

Context-Specific Toolbar Forms	Description
Help	The Help command launches the M-Star reference documentation in your web browser.

For a full description of each option, see Context-Specific Toolbar selections.