The proposed research effort is to develop computer models for practical flames that are usually embedded in turbulent flows such as those in aircraft engines and power generation plants. The improved modeling tools developed here can be extended for use in many other fields such as soot modeling, fire simulations, geophysical fluid dynamics, and environmental sciences. The principal investigators will furthermore continue their practice of mentoring a diverse group of high-school and undergraduate researchers to attract and prepare them for graduate careers in science and engineering.
A comprehensive understanding of flame stabilization is critical for clean and efficient combustion in future power, propulsion, and transportation systems. In this context, the large eddy simulation (LES) methodology provides a suitable framework for modeling flame stabilization and related combustion dynamics. However, current LES models are far from ideal and introduce simplifications that potentially alter the temporal dynamics in the simulations. Here, the LES modeling approach will be reformulated to introduce temporal statistics and a non-equilibrium dissipation rate. Simultaneously, high-speed imaging data will be combined with very large-scale direct numerical simulations (DNS) to validate central assumptions in the statistical data and LES model. An industry partner will collaborate with the research team to ensure the relevance of models and experimental data. Educational and outreach components will aid the transfer of new knowledge and technologies to the classroom and industry. The intellectual merit of the proposed work lies in providing a comprehensive understanding of flame stabilization beyond typical one-point, ensemble statistical averages and will enable the development of a robust and predictive computational modeling. It will take advantage of recent advances in high-speed laser-based imaging and DNS to expand the range of applicability of the LES modeling approach. The CFD models and experimental data developed here will be made accessible to the gas turbine industry and the well-established international working group on turbulent non-premixed flames (TNF).
