## Solver: overRhoPimpleDyMFoam Description

overRhoPimpleDyMFoam is a pressure-based solver designed for transient simulations of compressible flow. It handles laminar and turbulent, single-phase flows with temperature and density variations (it solves the energy equation).

Based on rhoPimpleFoam, the solver enhances its predecessor’s capabilities by incorporating overset (Chimera) meshes. This advancement makes the solver particularly suitable for scenarios involving significant object motion, where traditional dynamic meshes prove inadequate.

The overset framework offers a universal approach to implementing overset meshes for both stationary and dynamic scenarios. It utilizes mappings from cell to cell across various, separate mesh regions to create a unified domain. This approach facilitates intricate mesh movements and interactions without the drawbacks typical of mesh deformation.

The solver uses the PIMPLE (merged PISO-SIMPLE) algorithm for pressure-momentum coupling. This algorithm leverages the strengths of both PISO and SIMPLE methods for pressure-velocity coupling, ensuring robustness in handling transient flows with large time steps. This approach is supplemented by under-relaxation techniques to secure convergence stability. It supports both Multiple Reference Frame (MRF) and porosity modeling and allows easy integration of passive scalar transport equations and source terms. The solver handles dynamic meshes.

The overset mesh capabilities increase the applications of the solver for the cases where the mesh movement is significant and cannot be handled with standard dynamic mesh functions. In the turbomachinery, the analysis of the rotating components can be performed. In the aerospace industry, high-speed flows can be analyzed around flaps and landing gear. Missile and projectile aerodynamics can be performed for the military industry.

## Solver: overRhoPimpleDyMFoam Features

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

- High-Speed Aerodynamics
- Subsonic Flow
- Transonic Flow
- Pressure-Based Solver
- Overset (Chimera) Meshes

- Laminar and Turbulent (RANS, LES, DES)
- Equation of State Models
- Rotating Objects:
- Multiple Reference Frames (MRF)
- Rotating Mesh Motion

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

## Solver: overRhoPimpleDyMFoam Application

**Aerospace Industry**

- High Speed Aircraft with Significant Motion
- High Speed Flow around Flaps
- High Speed Flow around Moving Landing Gear

**Automotive Industry**

- High Speed Flow around Moving Spoilers

**Turbomachinery**

- Interaction between Stationary and Rotating Components

**Military Industry**

- Missile and Projectile Aerodynamics

## Solver: overRhoPimpleDyMFoam Compressible Solvers Comparison

Compressible Solvers In this group, we have included single-phase, pressure and density-based solvers that can handle flows with significant variations in density, mostly applicable for and **high-speed aerodynamics** (**Ma > 0.3**)

**Subsonic / Transonic, Steady-State, Ma < 1**

- rhoSimpleFoam steady-state, pressure-based, small density changes
- overRhoSimpleFoam extension of rhoSimpleFoam with Overset

**Subsonic / Transonic, Transient, Ma < 1**

- rhoPimpleFoam transient, pressure-based, small density changes, DyM
- overRhoPimpleDyMFoam extension of rhoPimpleFoam with Overset, DyM

**Transonic / Supersonic, Pressure-Based, Ma > 1**

- sonicFoam transient, pressure-based, shock waves
- sonicDyMFoam extension of sonicFoam with DyM

**Transonic / Supersonic, Density-Based, Ma > 1**

- rhoCentralFoam transient, density-based, shock waves
- rhoCentralDyMFoam extension of rhoCentralFoam with DyM

- Ma - Mach Number
- DyM - Dynamic Mesh
- Overset - also known as Chimera Grid (Method)

## Solver: overRhoPimpleDyMFoam 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 | \(T\) [\(K\)] |

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

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