News

 

Notus is still under active development (till version 1.0.0).

18/2023 0.6.0 release

  • Navier-Stokes
    • Subsonic compressible method (material properties: perfect gas, Peng Robinson, polynomial and neutral network material laws)
      WALE LES model
  • Multiphase
    • MOF: analytic formula for tetrahedra and Gauss-Newton algorithm
    • Conservative VOF-PLIC method (Weymouth)
    • Level-set: reinitialisation with Closest Points + Kinks
    • Smoothing: B-spline cubic kernel smoothing
    • Phase change: linearised enthalpy method
  • Immersed boundaries
    • Repartitioning process to exclude « solid » partitions from the domain
  • Miscellaneous
    • Update build system
    • Non-regression: implement database in python script, convergence tools
    • Automatic checkpoint file names
    • NTS language improved
    • Solvers: refactor the solver interfaces
  • …and some minor improvements and bugs fixed here and there.

10/2020 0.5.0 release

  • Immersed boundaries

    • Framework improved
    • Explicit part improved
    • Cut cells generation improved
    • Some test cases added

  • Schemes

    • WENO3/5 schemes optimized (CPU time)
    • HOUC3/5 schemes added
    • Lax-Wendroff TVD limiters addition – minmod, Van Leer, MC, Sweby limiter, TVDal, & TVDblend
    • QUICK implicit scheme for scalar equations added

  • Navier-stokes

    • Momentum preserving method improved
    • Driving pressure added (Boussinesq approximation)

  • Multiphase

    • Level-set: some heaviside approximations added
    • MOF2D: Implement MOF in axisymmetric coordinates
    • MOF2D: Navier boundary condition added
    • MOF2D: add support of immersed boundaries in MOF reconstrution
    • MOF3D: analytic reconstruction improved
    • Height function: with axisym coordinate system (VOF-PLIC + MOF)
    • 3D curvature computation with height function improved

  • Miscellaneous

    • notus.py script modifications + Linux Slurm template
    • Add a scalability mode in Python script
    • Add ray-tracing to shapes
    • Unify all build scripts into build_notus.sh
    • Add generic routines for algebraic operations that include OpenMP directives
    • Some code architecture changes
    • Add a checkpoint metric (cpu_time or time_iteration)
    • Add user fields and variables initialization routines
    • Doc updated

  • IO

    • ADIOS single-precision support
    • Third party T3PIO library
    • XMDF, Pixie, ADIOS2 file format (3D only)

  • …and some minor improvements and bugs fixed here and there.

 

02/2020 0.4.0 release

  • Immersed boundaries
    • New 2D/3D methods for Cartesian grids that reduce stencil size and/or improve precision
    • Some explicit schemes developed to be compatible with immersed boundaries (LW TVD Superbee)
  • Schemes
    • Lax-Wendroff TVD Superbee limiter for scalar and Navier-Stokes
    • Some schemes compatible with asymmetric coordinate system
    • User implicit scheme for scalar equation
    • Implicit second order schme for diffusion and rectilinear (stretched) grids
    • SBDF3 for energy equation
    • Optimized WENO schemes for the inertial term on uniform grids
  • Navier-stokes
    • Pressure correction method : approximation of Dodd (density) and Frantzis (boundary condition)
    • Implicit / Explicit / Crank-Nicholson integration of the gravity term
  • Turbulence
    • RANS k-omega & v2-f (first step)
    • Improved statistic module
  • Multiphase
    • Improved redistanciation
    • MOF 3D reconstruction, add filters to MOF 2D
    • Refined grid approach (MOF, VOF-PLIC)
    • Height function computation of curvature (MOF, VOF-PLIC)
    • Momentum preserving method
  • Performance
    • Set-up of Hypre solvers done only once
    • Improved performance of some key routines
    • Removed limitation to 2.2 billion cells in partitioning
    • Hybrid OpenMP / MPI approach (1st step)
  • Miscellaneous
    • Robin boundary conditions for scalar
    • Quadratic boundary condition schemes
    • Validation improved
    • Add several diagnostic tools
    • NaN detection to stop simulations
  • Linear system solver
    • Add a « Notus » solver (BiCGStab)
  • IO
    • Add probe point and probe lines
    • Improved checkpoint / restart
    • Add EnSight Gold writer
  • …and some bugs fixed here and there.

 

03/2019 0.3.0 release

  • NTS files
    • Validation of the code
      • new validation script notus.py that includes parametric validation (@PARAMETER)
      • cleanup of some test case files (reference solution, initialization, source term can be written in the NTS file)
    • Material block (solid, fluid). Phase initialization is independent of phase advection.
    • Immersed boundary (by equation, several immersed boundaries now possible)
    • Time step: fixed or adaptive
    • Post processing
      • print fields on a set of probe points and/or lines
      • Boundary condition:
      • line_segment (2D) and rectangle/circle (3D) shapes
    • Robin boundary condition (for scalar equation)
    • Checkpoint/restart
      • use of ADIOS bp files (it is possible to restart with a different number of processors)
      • initialization of a simple field thanks to a bp file
      • It is possible to set the final time instead of the number of iterations
  • DOC
    • Improve documentation : installation guide, howtos, best practices, detailed numerical schemes, etc.
  • MULTIPHASE
    • MOF 2D : filament treatment
    • MOF 3D : polyhedron flood algorithm, polyhedron clipping algorithm
    • Stable and accurate advanced Level Set methods (advection, reinitialization: eikonal, HCR2)
    • Front tracking interface representation: coupling with FronTier (C++) library for 2D flows with surface tension
  • IMMERSED BOUNDARIES
    • 2D and 3D improvements
    • SBDF2 method for advection terms (NS, energy, species) coupled with high-order explicit schemes (WENO3, WENO5), various fluxes (Godunov, LW, FLIC, FORCE) and NSSP time integration schemes.
    • New interpolation/reconstruction/finite difference schemes (generic Lagrange, WENO, Peskin, etc.)
  • MISCELLANEOUS
    • 2D asymmetric (Navier-Stokes, Energy, Level-set)
    • Add a Poisson equation (used to initialize hydrostatic pressure)
    • Renaming of some variables, routines
    • MPI exchange on edges
    • Experimental works: generic lagrangian particles and semi-lagrangian advection schemes
    • New test cases added
    • Notus can ben run from any directory (if included in PATH variable)
    • New structures for boundary conditions
    • New objects (torus, half space)
  • … and some bugs fixed here and there.
 

12/2018 New open positions! Three internships granted: see offers

11/2017 New open position offer

07/2017 Coupling with LIS library of solvers and preconditioners (some scalability tests)

01/2017 0.2.0 release 

01/2016 0.1.0 release

09/2015 Web site creation

01/2015 Start of the project