Terascale High-Fidelity Simulations of Turbulent Combustion with Detailed Chemistry

Sponsored by

U.S. Department of Energy, Office of Science, Grants and Contracts Division
Scientific Discovery through Advanced Computing (SciDAC)
Computational Chemistry

Project Summary

Direct numerical simulation (DNS) is a mature and productive research tool in combustion science that is used to provide high-fidelity computer-based observations of the micro-physics found in turbulent reacting flows. DNS is also a unique tool for the development and validation of reduced model descriptions used in macro-scale simulations of engineering-level systems. Because of its high demand for computational power, current (gigascale) state-of-the-art DNS remains limited to small computational domains (i.e. small Reynolds numbers) and to simplified problems corresponding to adiabatic, non-sooting, gaseous flames in simple geometries. The objective of this research proposal is to use terascale technology to overcome many of the current DNS limitations.

The effort will leverage an existing SNL DNS capability, named S3D, and a PSC/SNL collaborative effort for efficient implementation of S3D on massively parallel processors (MPP) computers. S3D is a compressible Navier-Stokes solver coupled with an integrator for detailed chemistry, and is based on high-order finite differencing, high-order explicit time integration, and conventional structured meshing. We propose here to re-design S3D for effective use on terascale high-performance computing platforms, and to enhance the code with new numerical and physical modeling capabilities. The list of proposed numerical developments includes: an implicit/explicit additive Runge-Kutta method for efficient time integration; an immersed boundary method to allow for geometrical complexity; and an adaptive mesh refinement (AMR) capability to provide flexible spatial resolution. The list of proposed physical modeling developments includes: a thermal radiation capability; and a multi-phase capability including soot particles and liquid fuel droplets.

The new MPP S3D software will be object-oriented and adapted to fit into an advanced software framework, known as the Grid Adaptive Computational Engine (GrACE) framework. GrACE is a MPP framework targeted for AMR applications and includes load-balancing capabilities. In addition, S3D will be made compliant to a software interoperability standard, the Common Component Architecture (CCA) developed by a consortium of DOE laboratories and academic institutions. The CCA environment will allow exchanging software components developed by different teams working on complementary tasks. It will allow in particular the re-use of components developed by a separate SNL-led research project [1] that is closely related to, and coordinated with, this proposal, and that focuses for instance on developing an AMR component.

We plan to demonstrate the performance and capabilities of the new DNS code in a series of demonstration studies selected for both their technical challenge and scientific value. This includes: the simulation of compression-ignition of a gaseous or liquid, hydrocarbon fuel in a turbulent inhomogeneous mixture; and the simulation of NOx emissions from hydrocarbon-air turbulent jet diffusion flames.

Finally, the objective of our proposal is also to establish a consortium of research institutions (PSC, SNL, UMD, UMI, UWI) that will bring together a critical mass of interdisciplinary skills, in order to tackle the increasing levels of complexity found in terascale technology. The proposed partnership will provide a suitable framework for ensuring the successful development and long-term support of the DNS code, as well as for maximizing its impact in the combustion research community.

[1] Najm, H., et al. (2001) “A Computational Facility for Reacting Flow Science”, SNL-led project funded by the DOE Office of Science, "SciDAC: Computational Chemistry".