## Solver: simpleCoalParcelFoam Description

simpleCoalParcelFoam is a Lagrangian, steady-state solver developed for simulating compressible, turbulent flows using both RANS and LES turbulence models, with a focus on coal combustion processes and chemical reactions. It incorporates models specific to coal chemistry, such as devolatilization and char combustion. The solver accounts for the thermal processes involved in coal combustion, including the effects of radiation, which are crucial for making accurate temperature predictions.

This solver is the steady-state version of coal-chemistry-foam. `simpleCoalParcelFoam`

employs a single cloud of coal particles, which can undergo the evaporation of any liquid or vapor content, devolatilization into the carrier phase, and surface reactions. The **SIMPLE** algorithm is used to solve the pressure-velocity coupling in the gas phase (continuous phase). The continuous fluid phase is solved using an Eulerian approach, employing the standard Navier-Stokes equations: continuity, momentum, species transport, and energy equations. The current flow field is utilized to evolve the solid particles and update their parameters. This two-way coupling is essential for accurately predicting combustion characteristics, pollutant formation, and the overall efficiency of coal-fired systems.

Particle motion is solved using a Lagrangian framework, where the motion of each particle is computed by integrating Newton’s second law of motion. Forces such as gravity, drag, and lift are considered.

The application of steady-state combustion is widespread, mostly in different types of combustors and furnaces, such as swirl combustors or the combustion of pulverized fuels with high-ash content.

## Solver: simpleCoalParcelFoam Features

**Steady-State****Compressible****Multiphase - Lagrangian Particles**

- Species Transport
- Lagrangian Particles:
- Coal Reacting 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)
- SIMPLE Algorithm
- Solution Limiters:
- Velocity Damping
- Pressure Limit
- Temperature Limit

## Solver: simpleCoalParcelFoam Application

**Energy**

- Swirling, Non-Premixed Industrial Methane-Air Burner
- Combustion of Pulverized Fuels with High Ash Contents

## Solver: simpleCoalParcelFoam 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: simpleCoalParcelFoam 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 | \(U\) [\(\frac{m}{s}\)] |

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

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

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

**Derivative Results**

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

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

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

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 | \(Avg\) \(Min\) \(Max\) |