Collaborative Research: High-speed Imaging Guided Large Eddy Simulation (LES) Model Development for Turbulent Flames

1403969/1403901 Meyer/Raman合作研究：湍流火焰的高速成像引导大涡模拟模型开发拟议的研究工作是开发实际火焰的计算机模型，这些火焰通常嵌入在湍流中，例如飞机发动机和发电厂中的火焰。 改进的建模工具可以扩展到许多其他领域，如烟尘建模，火灾模拟，地球物理流体动力学和环境科学。主要研究人员还将继续指导高中和本科研究人员的多元化群体，以吸引和准备他们的研究生职业生涯在科学和工程。火焰稳定的全面理解是未来的动力，推进和运输系统清洁和高效燃烧的关键。在这种情况下，大涡模拟（LES）方法提供了一个合适的框架，火焰稳定和相关的燃烧动力学建模。然而，目前的LES模型是远远理想的，并引入简化，可能会改变模拟中的时间动态。在这里，LES建模方法将重新制定引入时间统计和非平衡耗散率。同时，高速成像数据将与非常大规模的直接数值模拟（DNS）相结合，以验证统计数据和LES模型中的中心假设。行业合作伙伴将与研究团队合作，以确保模型和实验数据的相关性。教育和外联部分将有助于向课堂和工业界转让新知识和技术。所提出的工作的智力价值在于提供一个全面的理解火焰稳定超越典型的一点，合奏统计平均值，并将使一个强大的和预测性的计算建模的发展。它将利用高速激光成像和DNS的最新进展，扩大LES建模方法的适用范围。这里开发的CFD模型和实验数据将提供给燃气涡轮机行业和成熟的湍流非预混火焰（TNF）国际工作组。

1403969/1403901Meyer/RamanCollaborative Research: High Speed Imaging Guided Large Eddy Simulation Model Development for Turbulent FlamesThe 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).