Further development of a combustion Large Eddy Simulation (LES) code for the design of advanced gaseous combustion systems is described in this seventh quarterly report. CFD Research Corporation is developing the LES module within the parallel, unstructured solver included in the commercial CFD-ACE+ software. In this quarter, the Localized Dynamic subgrid Kinetic energy Model (LDKM) was improved and an initial Turbulent Artificial Neural Net (TANN) was developed. Validation and testing of the combustion LES code was performed for the Vanderbilt lean premixed combustor and the Loughborough University combustor port flow experiment.Next quarter, LES software development and testing will continue. Alpha testing of the code will continue to be performed on cases of interest to the industrial consortium. Optimization of the subgrid models will be pursued, particularly with the In Situ Adaptive Tabulation (ISAT) approach. Also next quarter, the demonstration of the TANN approach in CFD-ACE+ will be accomplished.ii 8321/7
INTRODUCTIONVision 21 combustion systems will require innovative low emission designs and low development costs if Vision 21 goals are to be realized. In this three-year project, an advanced computational software tool will be developed for the design of low emission combustion systems required for Vision 21 clean energy plants. The combustion Large Eddy Simulation (LES) software will be able to accurately simulate the highly transient nature of gaseous-fueled turbulent combustion so that innovative concepts can be assessed and developed with fewer high-cost experimental tests. During the first year, the project has included the development and implementation of improved chemistry (reduced GRI mechanism), subgrid turbulence (localized dynamic), and subgrid combustion-turbulence interaction (Linear Eddy) models into the CFD-ACE+ code. University expertise (Georgia Tech and UC Berkeley) has been utilized to help develop and implement these advanced submodels in the unstructured, parallel CFD flow solver. Efficient numerical algorithms that rely on in situ look-up tables or artificial neural networks have been implemented for chemistry calculations. Now, in the second year, the combustion LES software will be evaluated and validated using experimental data from lab-scale and industrial test configurations, including important benchmark data from DOE-NETL. During the last year, seven industrial and academic partners will take the combustion LES code and exercise it on problems of their choice. Final feedback and optimizations will then be implemented in the final release version of the combustion LES software.
EXECUTIVE SUMMARYWork in this seventh quarter (April -June 2002) has included further development of the LDKM and LEM subgrid models. Georgia Tech has extended the laminar ANN to include turbulent fluctuations. This TANN has been tested in their stand-alone LEM code and will be implemented and tested in the CFD-ACE+ code during the next quarter. Combustor LES validation has been carrie...