Joseph C. Oefelein
Robert S. Barlow
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Joseph C. Oefelein |
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Large Eddy Simulation of Complex Combustion Processes High-performance massively-parallel computing coupled with advanced experimental capabilities in combustion science offer unprecedented opportunities for synergistic, high-fidelity investigations of combustion phenomena. In particular, application of the Large Eddy Simulation (LES) technique to key target experiments now provides a unique ability to study coupled fluid-dynamic, thermodynamic, transport and combustion processes in the complex geometric and parameter space associated with a variety of combustion devices. This poster highlights how high-performance computational capabilities are being combined with the advanced laboratory and experimental diagnostic capabilities at the Combustion Research Facility (CRF) and elsewhere to bring our fundamental understanding of combustion science to the level needed for predictive simulations of complex combustion systems. The combination of high-fidelity simulations enabled by application of LES, unique high-performance software, and detailed experimental data from key target experiments facilitates the synchronized application of theoretical, computational, and experimental research in a centralized manner. Application of LES, using a formulation consistent with the application of a Direct Numerical Simulation (DNS), provides the formal ability to treat the full range of multidimensional time and length scales that exist in turbulent reacting flows in a computationally feasible manner and thus provides a direct link to key experimental studies of relevant combustion phenomena. These phenomena span a wide range of time and length scales, from the largest geometrically dominated turbulence scales to the smallest reactive-diffusive scales, and are inherently coupled through a cascade of nonlinear interactions. Given this complexity, our core effort has been focused on performing calculations that significantly exceed the time and resources available in industry and academia in a manner consistent with a National Laboratory’s role of using high-performance computing. To describe the overall approach, four key components are highlighted: 1) the application and role of software capabilities and high-performance computational resources, 2) model development and the role of canonical flows and DNS, 3) the need for rigorous validation of models using data acquired from carefully designed experiments, and 4) detailed characterization of complex combustion processes through joint-analysis of respective data. Information from validated LES solutions, combined with detailed laser-based experiments on well-defined benchmark flames, present new opportunities to understand the central physics of turbulence-chemistry interactions and for the development of accurate predictive models for advanced combustion systems. Once validated against experiments, high-fidelity simulations offer a wealth of information that cannot be measured directly. These data provide both a fundamental description of coupled processes not otherwise available and information required to improve and/or develop advanced engineering models for design. Significant improvements can be derived to provide enhanced accuracy and confidence in both our basic understanding and our ability to design state-of-the-art combustion systems.
Combustion Research Facility |