## Solver: interPhaseChangeDyMFoam Description

interPhaseChangeDyMFoam is a solver designed for two incompressible, isothermal immiscible fluids, which are capable of phase change, such as seen in cavitation. It is an extension of the interPhaseChangeFoam solver additionally supporting the functionality of dynamic mesh motion.

It handles laminar and turbulent flow, accommodating Newtonian and non-Newtonian fluids, utilizing the Volume of Fluid (VoF) method to accurately capture fluid interfaces. Additionally, it supports phase-change models, primarily for simulating cavitation but adaptable to other phase-change mechanisms.

The solver uses the **PIMPLE** (merged **PISO-SIMPLE**) algorithm for pressure-momentum coupling. It supports Multiple Reference Frame (MRF) and porosity modeling and allows easy integration of passive scalar transport equations and source terms.

The dynamic mesh capabilities of this solver expand its scope for analyzing moving objects. It enables the analysis of phase changes in scenarios such as cavitation around hydrofoils, propellers, and hydraulic pump systems, where boundary motion is significant. Additionally, in the piping industry, it facilitates the prediction of cavitation in valves, supporting simulations involving moving parts.

## Solver: interPhaseChangeDyMFoam Features

**Transient****Incompressible****Multiphase - Volume of Fluid (VoF)**

- 2 Immiscible Fluids (Liquid & Vapor)
- Cavitation
- Phase Change Models:
**Schnerr-Sauer**Merkle **Kunz - Dynamic Mesh Motion

- Laminar and Turbulent (RANS, LES, DES)
- Newtonian and Non-Newtonian Fluid
- Pressure-Based Solver
- Rotating Objects:
- Multiple Reference Frames (MRF)
- Rotating Mesh Motion

- Passive Scalar
- Porosity Modeling
- Buoyancy
- Source Term (explicit/implicit)
- PIMPLE Algorithm
- MULES Algorithm
- Solution Limiters:
- Velocity Damping

## Solver: interPhaseChangeDyMFoam Application

**Marine**

- Time-dependent Cavitation around Hydrofoils or Propellers

**Rotating Machines**

- Time-dependent Cavitation in Hydraulic Pump

**Piping**

- Time-dependent Cavitation in Pipe Systems or Valves

## Solver: interPhaseChangeDyMFoam Multiphase - Phase Change Solvers Comparison

Phase Change Solvers In this group, we have included solvers implementing **Phase Change** models to handle cavitation, and surface evaporation/condensation (liquid and its vapor phases).

**Phase Change - Cavitation**

- cavitatingFoam 2 immiscible fluids, dedicated to cavitation, Homogeneous Equilibrium Model (HEM)
- interPhaseChangeFoam 2 immiscible fluids, dedicated to cavitation, VoF, Phase Change Models: Schnerr-Sauer, Merkle, Kunz

- cavitatingDyMFoam extension of cavitatingFoam with DyM
- interPhaseChangeDyMFoam extension of interPhaseChangeFoam with DyM
- overInterPhaseChangeDyMFoam extension of interPhaseChangeFoam with Overset, DyM

**Phase Change - Condensation / Evaporation**

- interCondensatingEvaporatingFoam 2 immiscible fluids, phase changes (evaporation and condensation) between a fluid and its vapor phase

- VoF - Volume of Fluid
- DyM - Dynamic Mesh
- Overset - also known as Chimera Grid (Method)

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

Phase Volume Fraction | \(\alpha\) [\(-\)] |

Hydrostatic Perturbation Pressure | \(p - \rho gh\) [\(Pa\)] |

**Hydrostatic Perturbation Pressure** This value represents the pressure without the hydrostatic component (minus gravitational potential). Read More: Hydrostatic Pressure Effects

**Derivative Results**

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

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

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

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 | \(WSS\) [\(Pa\)] |

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