Projects / FLASH Code


The FLASH code is a modular, adaptive, parallel simulation code capable of handling general compressible flow problems in astrophysical environments. It has been designed to allow users to configure initial and boundary conditions, change algorithms, and add new physical effects with minimal effort. It uses the PARAMESH library to manage a block-structured adaptive grid, placing resolution elements only where they are needed most. It uses the Message-Passing Interface (MPI) library to achieve portability and scalability on a variety of different message-passing parallel computers.

Operating Systems

Recent releases

  •  25 Oct 2006 23:42

    Release Notes: This release adds new gravity solvers, a source term for stirring, a nuclear burning network, a directionally split 8wave MHD solver, and an equation of state for fully ionized plasma of arbitrary degeneracy. It also includes Lagrangian tracer particles for the uniform grid. API changes include complete interface definitions of the units' API, support for face-centered discretization variables, curvilinear geometry in the meshes, and more robust boundary conditions handling. Two methods of parallel I/O support have been added. New test cases have been added.

    •  07 Jun 2003 16:14

      Release Notes: New features include cosmology routines. Improvements include better support for non-planar geometries (in mesh and artificial viscosity calculations) and extensive code cleanup. Optimizations include better timestep calculation and much improved multi-grid routines.

      •  05 Dec 2002 06:12

        Release Notes: In this release, improvements include expanded documentation, internal and in the users guide, a cleaned-up code base, including better support for many compilers, better I/O with higher serial performance, extended data stored in the checkpoint files, and tools to convert output to TecPlot or ChomboVis formats, better support for non-Cartesian geometries, and much-improved gravity solvers. There are new features for the MHD and hydro (PPM) solvers, and support for cosmological expansion.

        •  10 Jun 2002 04:23

          Release Notes: This release increases portability, improves modularity, includes additional new solvers and many additional test setups, provides cleaner interfaces, and reorganizes the framework to make it cleaner and more flexible. There are selected specific feature updates, including isolated boundary conditions for gravity, support for active particle dynamics and passive particle tracers, new and improved fidlr/xflash routines, and user contributed modules radiative cooling, static and gaussian transient heating, Spitzer viscosity and conductivity, and ionization.

          •  31 Jan 2002 16:23

            Release Notes: This release contains many new features and bugfixes. The API was cleaned up. The program now compiles on a wider range of Intel Linux and Compaq compilers. New poisson solvers for gravity, a new burner, new comparison routines, and resistive MHD were added.

            Recent comments

            04 Dec 2002 16:09 ljdursi

            FLASH2.2 Release
            We are pleased to announce the immediate available of FLASH2.2. All
            users of previous versions are encouraged to upgrade. The download
            is available at:
            (note the 's' in https). You will need your username and password
            from previous downloads.

            New users can request the code at:


            The major changes are summarized below:

            -- Expanded documentation

            -- Better support for Intel, Compaq, and Lahey compilers

            -- Enhancements to the setup script (-nxb, -with-module, -stack)

            -- HDF5 output is now the default

            o runtime parameters are now stored in HDF5 files

            o minima and maxima attributes accompany the variable


            o serial I/O performance improved

            o ability to restart from a checkpoint file directly

            -- New conversion tools for TecPlot and ChomboVis

            -- PPM improvements

            o hybrid Riemann solver

            o further implementation of the CMA algorithm

            -- entropy now returned by all EOSs

            -- new model burners (kpp and arrhenius)

            -- gravity changes

            o optimizations to the multipole gravity solver

            o multigrid can use multipole coarse solve

            -- geometry enhancements

            o new prolongation routines for 1-d spherical and 2-d cylindrical


            o flux correction fixes in 1-d spherical coordinates

            o generalized restriction routine

            o improved support for non-Cartesian geometries in the diffusion


            -- initial support for cosmology

            -- integration of IBM HPM and PAPI performance monitor libraries

            14 Jun 2002 23:59 ljdursi

            New Release
            With FLASH2.2, we're hoping to move to a more regular release schedule, with patches everytime something major improves.
            News will always be posted to the FLASH-USERS mailing list that you'll have the option of being subscribed to when you register for the software; we'll also keep the freshmeat info up-to-date. Comments and questions should go to the mailing lists.


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