Create: Scalar¶
Scalars are single-valued field quantities used to represent local species concentrations. Their evolution across the fluid lattice is governed by the advection–diffusion–reaction equation and is solved in tandem with the fluid field, enabling dynamic coupling between species concentration, viscosity, and density. This continuous-phase representation is used to model mixing, blending, and chemically reactive flows. Scalar fields can enter the system via a scalar injection, a boundary condition, or an initial background concentration.
Scalar fields can participate in user-defined reactions, allowing local species concentrations to evolve due to chemical or physical processes in addition to advection and diffusion. These reactions are evaluated on a voxel-by-voxel basis using user-defined kinetics, which may depend on local fluid or particle properties, species concentrations, and other custom variables.
Representations
Scalar Field: Scalar fields are continuous field variables that evolve according to the advection-diffusion-reaction equation. Scalar fields are typically used to model species mixing and transport processes (e.g., blending and dispersion). The species represented by the scalar field can occupy both the fluid and the particles. As such, species contained within the fluid can interact with species in the particles via particle-scalar coupling.
Reaction Types
Fluid Reaction: Fluid reactions are applied to scalar fields and can be calculated on a voxel-by-voxel basis per a user-defined set of reaction kinetics. These kinetics can be functions of the local species concentrations, as well as the local fluid/particle properties. Reactions are solved in tandem with the advection-diffusion equation, particle advection, and the fluid transport algorithm.
Scalar Output
Scalar Output Data: The local scalar concentration can be exported during the simulation both as reduced statistical quantities and as spatial datasets for analysis and visualization. In addition, reaction rates and scalar addition or removal rates at inlets and outlets are recorded.