ExaCT Co-Design Center: Proxy App Software

The Center for Exascale Simulation of Combustion in Turbulence (ExaCT) is actively developing a number of "proxy apps" that represent key aspects of structured-grid adaptive mesh PDE-based combustion simulations. A subset of these proxy apps are available to the public and may be obtained following the instructions in the Downloads section below. Currently, the set includes the apps below.

For more information about ExaCT, see the ExaCT web site.

WARNING: Each ExaCT proxy app is designed to represent a specific set of issues related to combustion simulation. None of them are, by themselves, representative of the full application. If these proxy apps are used out of context, the results may be misleading. If you are interested in investigating a specific issue, we encourage you to contact us to help you identify the appropriate proxy app to work with.


  • Basic PDE discretization methodology

    • Exp_CNS_NoSpec: A simple, explicit, stencil-based test code for integrating the the compressible Navier-Stokes equations. The code uses 8th order finite differences in space and a 3rd order, low-storage TVD RK algorithm in time. You can download the Exp_CNS_NoSpec proxy app by clicking here.

    • SMC: A minimalist high-order finite difference algorithm for combustion problems. It includes core discretizations for advection, diffusive transport and chemical kinetics. The models for computing diffusive transport coefficients have been replaced by a simplified approximation but the full structure of the discretization of the diffusive terms have been preserved. You can download the SMC proxy app by clicking here.

    • AMR_Exp_Parabolic: A simplified block-structured adaptive mesh refinement algorithm in two and three dimensions with subcycling in time. The algorithm solves a linear advection diffusion equation with a simple numerical method. This proxy app is intended to capture the communication pattern of an explicit AMR algorithm but does not represent an accurate characterization of floating point effort or relative costs of communication to computation. You can download the AMR_Exp_Parabolic proxy app by clicking here.

  • Linear Solvers

    • HPGMG-FV: A finite-volume multigrid solver that supports variable coefficient elliptic solves typical of those required by a low Mach number combustion algorithm. HPGMG-FV uses a hybrid parallel model that combines MPI with OpenMP. It supports a number of different variants of multigrid. You can download HPGMG-FV using git by typing the following command:

            git clone

      Make sure to use the code in the "finite-volume" folder of the hpgmg directory.

  • Uncertainty Quantification

    • UQ_proxy: This proxy app integrates the compressible Navier Stokes equations with constant viscosity and thermal conductivity; it then integrates the adjoint (in PRIMITIVE variables) to the CNS equations backwards in time, and computes sensitivities of the final density to the viscosity and thermal conductivity. You can download the UQ proxy app by clicking here.

      For additional information, contact Varis Carey

  • In-situ Topological Analysis

    • Topo_proxy: The attached file contains two proxy-apps for in-situ topological analysis, "localCompute" and "joinTrees". The "localCompute" proxy-app performs the local computation phase of the in-situ parallel merge tree computation. This local compute phase computes the merge tree for the data block assigned to the process. So the app takes as input a raw block of floats and computes the merge tree for that block and exits. The "joinTrees" proxy-app emulates the computation performed by a core or process during the "join" phases of the merge tree computation. The merge tree computation has a local compute phase followed by join phase which performs a hierarchical k-way merge to compute the merge tree. You can download these proxy apps by clicking here.

      For additional information, contact Aaditya G. Landge, Attila Gyulassy, Peer-Timo Bremer, Valerio Pascucci

  • Chemical mechanism integration

    • vodeDriver: A driver to evolve a representative set of ODEs associated with chemical combustion kinetics using the VODE algorithm, by Brown, Hindmarsh and Byrne. Coming soon.