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 PDE-based combustion simulations. A subset of these proxy apps are available to the public and can be obtained from https://ccse.lbl.gov/ExaCT/index.html.

Basic PDE discretization methodology

  1. Exp_CNS_NoSpec: A simple stencil-based test code for computing the hyperbolic component of a time-explicit advance for the Compressible Navier-Stokes equations using 8th order finite differences and a 3rd order, low-storage TVD RK algorithm in time.
  2. 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 The models for computing diffusive transport coefficients have been replaced by a simplified approximation but the full structure of the discretization of the diffusive terms have been preserved.
  3. 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.

Linear Solvers

  1. 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.

Chemical mechanism integration

  1. 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.

Uncertainty Quantification

  1. Coming soon

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.

ExaCT is funded by the DoE office of Advanced Scientific Computing Research (ASCR). Dr. Karen Pao is the program manager and Dr. William Harrod is the director of the ASCR Research Division. U.S. Department of Energy: Office of Science Stanford University The University of Utah Georgia Institute of Technology Lawrence Berkeley National Laboratory Lawrence Livermore National Laboratory Oak Ridge National Laboratory The University of Texas at Austin Rutgers: The State University of New Jersey National Renewable Energy Laboratory (NREL) Los Alamos National Laboratory Sandia National Laboratories