## Solver: reactingParcelFoam Description

reactingParcelFoam is a transient solver developed for simulating compressible, turbulent flows with the capability to manage simple reactions between multiphase particle clouds in a continuous fluid phase. This solver is intended to model the basic flow and interactions of parcels within a fluid while considering chemical reactions and transformations. The solver can also handle combustion and chemical reactions.

This solver uses the **PIMPLE** algorithm to solve the pressure-velocity coupling of the fluid phase. The solver can also handle combustion and chemical reactions. This solver operates in the Eulerian-Lagrangian framework. The continuous fluid phase is solved in the Eulerian approach using the standard Navier-Stokes equations: continuity, momentum, species transport, and energy equations. The turbulence models (RANS and LES) are supported.

Particle motion is being solved using the Lagrangian framework. The motion of each particle is computed by integrating Newton’s second law of motion. Gravity, drag and lift forces are considered. The particles are considered rigid and spherical, and rotational motion is neglected.

One-way or two-way coupling between continuous and particle phases can be applied. In one-way coupling, the primary phase (e.g., fluid) affects the secondary phase (e.g., particles), but the secondary phase does not affect the primary phase. One-way coupling simplifies the computations and reduces computational costs. However, it may lead to inaccuracies in cases where the interaction between phases is significant, and feedback from the secondary phase is important.

In two-way coupling, the primary phase affects the secondary phase, and the secondary phase also exerts influence back on the primary phase. It provides more accurate solutions in cases where interactions and feedback between the phases are substantial. But, it is computationally expensive.

The solver can be applied to modeling spray combustion systems, fuel injection systems, powder production, and many others.

## Solver: reactingParcelFoam Features

**Transient****Compressible****Multiphase - Lagrangian Particles**

- Species Transport
- Lagrangian Particles:
- Multiphase Composition of Particles

- Chemical Reactions
- Evaporation and Boiling
- Combustion Modeling

- Laminar and Turbulent (RANS, LES, DES)
- Multicomponent (mixture)
- Perfect Gas Model
- Pressure-Based Solver
- Rotating Objects:
- Multiple Reference Frames (MRF)

- Passive Scalar
- Porosity Modeling
- Heat Transfer
- Heat Source
- Radiation
- Buoyancy
- Source Term (explicit/implicit)
- Transonic Flow
- PIMPLE Algorithm
- Solution Limiters:
- Velocity Damping
- Pressure Limit
- Temperature Limit

## Solver: reactingParcelFoam Application

**Energy**

- Spray Combustion (e.g. Spray Combustion)
- Fuel Injection Systems
- Spray Drying
- Particle-Laden Reacting Flows
- Powder Production

## Solver: reactingParcelFoam Species & Reactions Solvers Comparison

Species & Reactions Solvers In this group, we have included compressible (pressure-based) solvers that can be used to simulate: **Species Transport**, **Multicomponent Gas Mixtures**, **Chemical Reactions**, **Combustion**.

**Multicomponent**

- simpleReactingParcelFoam steady-state, multiphase particle clouds
- reactingParcelFoam transient, multiphase particle clouds

**Spray**

- sprayFoam transient, liquid particles only, dedicated to fuel spray combustion
- sprayDyMFoam extension of sprayFoam with DyM

**Coal**

- simpleCoalParcelFoam steady-state, coal particles only
- coalChemistryFoam transient, coal particles only

**Gas***

- reactingFoam fluids with minor density fluctuations (caused by pressure variance), no buoyancy
- rhoReactingFoam fluids with density variations due to reactions, no buoyancy
- rhoReactingBuoyantFoam extension of rhoReactingFoam with buoyancy forces

- * All solvers in this group are transient

- DyM - Dynamic Mesh

## Solver: reactingParcelFoam Alternative Solvers

In this section, we propose alternative solvers from different categories, distinct from the current solver. While they may fulfill similar purposes, they diverge significantly in approach and certain features.

## Solver: reactingParcelFoam Results Fields

This solver provides the following results fields:

**Primary Results Fields**- quantities produced by the solver as default outputs**Derivative Results**- quantities that can be computed based on primary results and supplementary models. They are not initially produced by the solver as default outputs.

**Primary Results Fields**

Velocity | \(U\) [\(\frac{m}{s}\)] |

Pressure | \(p\) [\(Pa\)] |

Temperature | \(T\) [\(K\)] |

Species Mass Fraction | \(Y_i\) [\(-\)] |

**Derivative Results**

Density | \(\rho\) [\(\frac{kg}{m^{3}}\)] |

Vorticity | \(\omega\) [\(\frac{1}{s}\)] |

Mach Number | \(Ma\) [\(-\)] |

Courant Number | \(Co\) [\(-\)] |

Peclet Number | \(Pe\) [\(-\)] |

Stream Function | \(\psi\) [\(\frac{m^2}{s}\)] |

Q Criterion | \(Q\) [\(-\)] |

Wall Functions (for RANS/LES turbulence) | \(y^+\) [\(-\)] |

Wall Shear Stress | \(WSS\) [\(Pa\)] |

Wall Heat Flux | \(\phi_q\) [\(W/m^2\)] |

Turbulent Fields (for RANS/LES turbulence) | \(k\) \(\epsilon\) \(\omega\) \(R\) \(L\) \(I\) \(\nu_t\) \(\alpha_t\) |

Volumetric Stream | \(\phi\) [\(\frac{m^{3}}{s}\)] |

Passive Scalar | \(scalar_i\) [\(-\)] |

Forces and Torque acting on the Boundary | \(F\) [\(N\)] \(M\) [\(-\)] |

Force Coefficients | \(C_l\) [\(-\)] \(C_d\) [\(-\)] \(C_m\) [\(-\)] |

Average, Minimum or Maximum in Volume from any Result Field | \(Avg\) \(Min\) \(Max\) |