Free Software

OpenFOAM v14, produced by CFD Direct and released via The OpenFOAM Foundation, is the best version of OpenFOAM today.  By “best” we mean the software which best meets the critical needs of users — availability, usability, robustness and extensibility. It is redesign work that has greatest impact on these criteria and which CFD Direct has provided time and again, delivering new, improved software components. Examples include modular solvers, NCC, modular Lagrangian, units, field functions, coded file input, bounded MULES, dynamic zones, improved dynamic meshes, snappyHexMeshConfig, fvModels and fvConstraints.

In 2026, CFD Direct made units a standard feature of Foundation OpenFOAM.  The feature allows users to accompany numerical parameters in input files with units, e.g. [ft/s] for feet per second.  When the data is read with units, the numerical value is converted into the base unit, i.e.metres per second [m/s] for the default SI unit set.  The new foamUnits utility makes units easy to use. Units provide both the flexibility to specify parameters in the units given in the real world problem, but they can also make us aware of the associated dimensions and ensure values we provide are dimensionally consistent. This gives the user greater certainty over correct specification of parameters.

CFD Direct have added field functions to OpenFOAM, which provide a flexible, convenient way to initialise non-uniform fields in OpenFOAM. The field functions are: zonal, corresponding to different zones; surfaces, corresponding to regions separated by surfaces; distanceFunction, calculated using a function of distance across the domain; and, coded, calculated using a coded function. Field functions are accompanied by the functionalFixedValue boundary condition (BC) for non-uniform values on boundary patches. The functionality removes the need for a separate pre-processing step to intialise fields and some specialised BCs.

In June 2025, Henry Weller at CFD Direct completed a rewrite of mesh zones and associated tools, released in OpenFOAM v13 by The OpenFOAM Foundation.  The aim behind the rewrite of mesh zones was to make them dynamic, so they would work effectively for complex CFD problems, especially involving moving meshes.  The new design includes createZones which provides a simpler, more powerful replacement for the lousy topoSet. Other utilities which have been rewritten, and are far better to use as a result, include setFields, refineMesh (making the separate refineHexMesh redundant), createPatch and subsetMesh.

In February 2025, there were significant improvements to MULES in the development line of OpenFOAM which make it extremely robust, easier to use, and quicker to run. The changes include: improvements to the iterative MULES algorithm to guarantee boundedness of solutions; a new control structure for the MULES parameters; an optional tolerance for limiter convergence for semi-implicit MULES; better control for sub-cycling the α-equation based on setting a function of the α-Courant number.