Openfoam

Openfoam
Openfoam
Type of	Open source field operation and manipulation
Developer	The OpenFOAM Foundation Ltd
Written on
operating system	Linux , UNIX
First edition
Latest version	5.0
License	GNU GPL
Site	openfoam.org

OpenFOAM ( English Open Source Field Operation And Manipulation CFD ToolBox ) is an open integrable platform for numerical modeling of problems in mechanics of continuous media .

Content

General characteristics

OpenFOAM is a freely distributed toolkit of computational fluid dynamics for operations with fields ( scalar , vector and tensor). Today it is one of the finished and well-known applications designed for FVM calculations.

OpenFOAM code, originally developed in the UK by OpenCFD, Limited , is currently supported and developed by the nonprofit organization The OpenFOAM Foundation, founded by Henry Weller (creator of FOAM source code), Chris Greenshields and Cristel de Rouvray. The code takes its name and ideology of construction from its predecessor FOAM (Field Operation And Manipulation). Initially, the program was intended for strength calculations, but as a result of many years of academic and industrial development, today it allows solving many different problems of continuum mechanics (but not limited to it), in particular:

Strength calculations;
Hydrodynamics of Newtonian and non-Newtonian viscous fluids in both the incompressible and compressible approximations taking into account convective heat transfer and the action of gravitational forces. To simulate turbulent flows, it is possible to use RANS models, LES and DNS methods. It is possible to solve subsonic, transonic and supersonic problems;
Problems of thermal conductivity in a solid;
There are many phase tasks, including the description of chemical reactions of the components of the flow;
Tasks related to the deformation of the computational grid;
Related tasks;
Some other problems, the mathematical formulation of which requires the solution of partial differential equations in complex geometry of the medium;
Parallelization of calculation for launching on multiprocessor systems (including cluster ones ).

The code is based on a set of libraries that provide tools for solving systems of partial differential equations both in space and in time. The working language of the code is OOP C ++ . In terms of this language, most of the mathematical differential and tensor operators in the program code (before being translated into an executable file) of the equations can be represented in a readable form, and the discretization and solution method for each operator can be chosen by the user during the calculation process. Thus, the concepts of a computational grid (discretization method), discretization of basic equations, and methods for solving algebraic equations are completely encapsulated and separated in the code. For example, the equation of conservation of momentum for a Newtonian incompressible fluid without the action of mass forces:

{\frac {\partial \rho \mathbf {U} }{\partial t}}+\nabla \cdot (\rho \mathbf {U} \mathbf {U} )-\nabla \cdot (\mu \nabla \mathbf {U} )=-\nabla p

{\ displaystyle {\ frac {\ partial \ rho \ mathbf {U}} {\ partial t}} + \ nabla \ cdot (\ rho \ mathbf {U} \ mathbf {U}) - \ nabla \ cdot (\ mu \ nabla \ mathbf {U}) = - \ nabla p}

can be represented as:

  solve
     ( 
         fvm :: ddt (rho, U) 
       + fvm :: div (rho, U, U) 
       - fvm :: laplacian (mu, U) 
         == 
       - fvc :: grad (p) 
     );

Along with the code, a set of “solver” programs is supplied, in which various mathematical models of continuum mechanics are implemented.

The program can run on Windows through a virtual machine ; there are also implementations that do not use additional add-ons ^[2] .

Relationship with standards

The OpenFOAM package has many utilities that allow you to convert third-party formats to the OpenFOAM format (for example, ANSYS, Fluent, Gambit, VTK, etc.). To access the utilities, you need to go to the $ FOAM_UTILITIES folder, this can also be done with the util ^[3] command.

Branches

blueCFD is a cross-compiled version of OpenFOAM to run on Windows operating systems, derived from OpenFlow. Includes additional tools and functionality used in OpenFOAM. Development is supported by blueCAPE.
FreeFOAM - OpenFOAM version independent of the operating system, portable and more convenient to install. The project is developing in parallel with the official releases of OpenCFD and does not have additional functionality. For assembly uses CMake. Since 2017, the project is no longer supported according to information from the project website.
OpenFlow is the add-on source code for the cross-compiled OpenFOAM distribution that runs on Windows operating systems. The OpenFOAM components in blueCFD are based on the OpenFlow source code. Development is supported by Symscape.
OpenFOAM-extend is supported by Wikki Ltd. This branch includes community development, most of which can be installed in the official version of OpenFOAM with minimal changes. The branch is being developed in parallel with the official version of OpenFOAM, but in the latest versions the extended branches are one to two years behind.

Relationship with other Open source projects

SALOME - a package for working with geometry and meshes
ParaView - a package for visualizing results and computational grids, comes by default with OpenFOAM

Notes

↑ OpenFOAM Version 5.0 (unspecified) .
↑ OpenFOAM for MS Windows
↑ Standard utilities

Literature

Darwish, M .; Mangani, L .; Moukalled, F. The finite volume method in computational fluid dynamics: an advanced introduction with OpenFOAM® and Matlab®. - 1 st ed .. - Springer , 2015 .-- T. 113. - xxiv + 791 s. - (Fluid mechanics and its applications). - ISBN 978-3-319-16873-9 .
Joey Bernard To CFD, or Not to CFD? (unspecified) . Linux Journal (September 19, 2011). Date of treatment November 13, 2016.

Links

[1] OpenFOAM Version 5.0 (unspecified) .

[2] OpenFOAM for MS Windows

[one-3] Standard utilities