pimpleFoam - OpenFOAM Solver

Solver: pimpleFoam   Description

pimpleFoam is a pressure-based solver designed for transient simulations of incompressible flow. It handles laminar and turbulent, single-phase flows under isothermal conditions, accommodating both Newtonian and non-Newtonian fluids.

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 Frames (MRF) and porosity modeling and allows easy integration of passive scalar transport equations and source terms. The solver handles dynamic meshes.

The versatility of the solver is very wide and ranges from the automotive industry (vehicle aerodynamics) to the aerospace industry (wing optimization, aircraft aerodynamics). Internal flows can also be calculated which finds applications in the piping industry, chemical and food industry (mixers and stirring tanks). Dynamic mesh capabilities further increase the potential use of the solver, including the rotating machinery (compressors, turbines, fans) but also wind turbines, piston movements, and many others.

Solver: pimpleFoam   Features

  • Transient
  • Incompressible
  • Single-Phase
  • Low-Speed Flows
  • PIMPLE Algorithm
  • Subsonic Flow (Ma < 0.3)
  • 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
  • Source Term (explicit/implicit)
  • Solution Limiters:
    • Velocity Damping

Solver: pimpleFoam   Application

Automotive

  • Car Aerodynamics with Transient Effects (LES considered)
  • Tire Aquaplaning

Aerospace

  • Aircraft Aerodynamics
  • Wing Optimization and Motion

Biomedical

  • Heart Valves

Rotating Machinery

  • Pumps
  • Propellers
  • Compressors
  • Turbines, Fans

HVAC

  • Fans and Pumps

Pipping

  • Flows through the Pipe and Junctions
  • Oscillating Inlets
  • Valve Motion

Pile Structures

  • Vortex Shedding on Bridges

Solver: pimpleFoam   Incompressible Solvers Comparison

Incompressible Solvers In this group, we have included single-phase, pressure-based solvers for low-speed flows with negligible variations in density, applicable for external and internal aerodynamics (Ma < 0.3) and hydrodynamics. These solvers use incompressibility features for stability and robustness.

Incompressible, Stedy-State - Main Solvers

Incompressible, Transient - Main Solvers

Incompressible, Transient - Simplified Solvers*

  • pisoFoam transient, PISO** algorithm
  • icoFoam transient, PISO** algorithm, laminar flows only (no turbulence), Newtonian fluids only
  • * Dedicated solvers for simplified scenarios, improve stability and computational efficiency
  • ** The PISO algorithm is used for cases with a small Courant number Co < 1
  • DyM - Dynamic Mesh
  • MRF - Multiple Reference Frame
  • SRF - Single Reference Frame
  • Overset - also known as Chimera Grid (Method)
  • SIMPLE - Semi-Implicit Method for Pressure-Linked Equations
  • PIMPLE - merged PISO and SIMPLE
  • PISO - Pressure-Implicit Split-Operator

Solver: pimpleFoam   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: pimpleFoam   Tutorial

Static Mixer

  • Transient simulation of a static mixer, using a passive scalar to track fluid dispersion.

Blood Flow

  • Transient simulation of blood flow in a vessel, including the modeling of non-Newtonian fluid properties and time-variable boundary conditions.

Solver: pimpleFoam   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

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

Kinematic Pressure \(p/\rho\)

\(p\) [\(\frac{m^{2}}{s^{2}}\)]

Kinematic Pressure It is a pressure normalized by density. To obtain pressure in Pascals [Pa], multiply kinematic pressure by the fluid’s reference density. Read More: Kinematic Fluid Properties

Derivative Results

Pressure

\(P\) [\(Pa\)]

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

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