## Solver: reactingFoam Description

reactingFoam is a pressure-based solver designed for transient simulations of compressible, reacting flows. It handles laminar and turbulent, multispecies flows with temperature and density variations (it solves the energy equation). This solver is well-suited for the simulation of combustion processes and chemical reactions within fluids, accommodating a variety of reaction kinetics and species transport mechanisms.

The solver uses the **PIMPLE** (merged **PISO-SIMPLE**) algorithm for pressure-momentum coupling, which leverages the strengths of both PISO and SIMPLE methods for pressure-velocity coupling, ensuring robustness in handling transient flows with large time steps. It enables adaptive adjustment of time step size within different regions by **Local Time Stepping** (**LTS**) functionality. It also supports Multiple Reference Frame (MRF), porosity modeling and allows easy integration of passive scalar transport equations and source terms.

The solver is mainly used for the analysis of burners in the energy industry and in environmental engineering for pollution modeling and control.

## Solver: reactingFoam Features

**Transient****Compressible****Single-Phase**

- Species Transport
- Chemical Reactions
- 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
- Source Term (explicit/implicit)
- Transonic Flow
- PIMPLE Algorithm
- Solution Limiters:
- Velocity Damping
- Pressure Limit
- Temperature Limit

## Solver: reactingFoam Application

**Energy:**

- Burners
- Combustion Chambers
- Pollution Modelling

## Solver: reactingFoam 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: reactingFoam 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.

- interMixingFoam incompressible, 3 fluids (2 miscible and 1 immiscible), VoF approach
- multiphaseEulerFoam incompressible, multiple miscible fluids, Euler-Euler approach

## Solver: reactingFoam 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 | \(Avg\) \(Min\) \(Max\) |