Nektar++ — The Complete Guide: Free High-Accuracy Simulation With Spectral/hp Elements

Nektar++ is an open-source framework for solving partial differential equations with the spectral/hp element method, developed at Imperial College London and the University of Utah. Instead of linear polynomials on each element, it uses high-order polynomials — achieving high accuracy with fewer degrees of freedom.

Nektar++

Imperial College London / University of Utah

A spectral/hp element framework for high-accuracy simulation.

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What you get

Incompressible flow solver — for transitional flows, vortices and DNS.
Compressible flow solver — for high-accuracy aerodynamics.
More solvers — cardiac electrophysiology, advection-diffusion-reaction and shallow water equations.
NekMesh — a tool for building high-order meshes with curved elements.
Python interface — for scripting workflows and post-processing.

Who it suits

Researchers and graduate students who need high accuracy in sensitive flows — transition to turbulence, acoustics or blood flow. It is not a tool for routine engineering design: it requires understanding of the numerical method and command-line work, mainly on Linux and macOS.

Related tools

For general engineering CFD — OpenFOAM. For turbulence with high-order finite differences — Xcompact3d. For formulating general equations with finite elements — FEniCS.