A fast and scalable open-source spectral element solver for CFD


Nek5000 is a free open-source simulation-software package that delivers highly accurate solutions for a wide range of scientific applications, including fluid flow, thermal convection, combustion and magnetohydrodynamics.

It features state-of-the-art, scalable, high-order spectral element-based algorithms that are fast and efficient on platforms ranging from laptops to the world’s fastest computers.

Nek5000’s users include over 400 scientists and engineers in academia, laboratories and industry.





  • Runs on all POSIX compliant operating systems
  • Written in Fortran77 and C
  • Pure MPI for parallelization
  • Proven scalability to over a million ranks
  • Easy-to-build with minimal dependencies
  • High-order conformal curved quadrilateral/hexahedral meshes
  • 2nd/3rd order adaptive semi-implicit timestepping
  • Efficient multigrid preconditioners
  • Parallel I/O
  • Lagrangian particle tracking
  • Moving mesh and free surface flow
  • Efficient Low Mach-number formulation
  • Magnetohydrodynamics (MHD)
  • Conjugate fluid-solid heat transfer
  • Meshing tools and converters
  • VisIt & Paraview support for data analysis and visualization

For more information check out our project on GitHub.