The FLASH Code

The FLASH code, currently in its 4th version, is a publicly available high performance application code which has evolved into a modular, extensible software system from a collection of unconnected legacy codes. FLASH consists of inter-operable modules that can be combined to generate different applications. The FLASH architecture allows arbitrarily many alternative implementations of its components to co-exist and interchange with each other. A simple and elegant mechanism exists for customization of code functionality without the need to modify the core implementation of the source. A built-in unit test framework combined with regression tests that run nightly on multiple platforms verify the code.


Physics Solvers :

  • Hydrodynamics: Unsplit PPM and WENO; Split PPM; 2T+Radiation
  • Magnetohydrodynamics: Unsplit Staggered Mesh; Split 8 wave
  • Equation of State: Ideal gas; Degenerate Ionized Plasma; Multimaterial
  • Radiation Transfer: Multigroup Flux-limited Diffusion
  • Diffusion and Conduction: Implicit with AMR
  • Laser Energy Deposition: Geometric Optics with Inverse Brensstrahlung
  • Quiet Start
  • Opacity: Constant; Multimaterial Tabular
  • Particles: Tracer; Massive; Sink; Charged
  • Nuclear Burning
  • Gravity: Constant; PointMass; Planar; Self Gravity
  • Cosmology
  • Magnetic Resistivity, Conductivity
  • Primordial Chemistry


  • Driver: Split; Unsplit
  • Grid: Uniform Grid; AMR (PARAMESH); AMR (Chombo)
  • GridParticles: Lagrangian Framework
  • GridSolvers: Multigrid; Multipole; Barnes-Hut Tree; PFFT; Direct Solvers for Uniform Grid
  • IO: HDF5 ; PnetCDF
  • Multispecies
  • RuntimeParameters
  • Monitor: MPI Timers; Hooks for TAU

  • Downloads