Advanced radiation models to enable direct comparisons between computed and measured temperatures and compositions in laminar and turbulent flames

1604446 -在可预见的未来，HaworthCombustion将继续在推进和发电领域发挥核心作用。这包括轻型和重型道路车辆（轿车和卡车）的发动机。制定了积极的燃油经济性和排放目标，以同时减少能源消耗和污染物排放，包括温室气体排放。与此同时，石油衍生燃料（例如生物燃料）的替代品正在被引入，以减少以燃烧为基础的能源系统的碳足迹。预测数学/计算工具是迫切需要的，以便工程师能够优化未来的发动机和其他燃烧系统，以最小的油耗和排放获得最大的性能，同时能够引入未来的可持续燃料。这些工具必须包括关键底层物理过程的准确表示。由于其高温，辐射传热在燃烧系统中很重要，但由于其极端的复杂性，迄今为止受到的关注相对较少。该项目将开发先进的辐射模型，这些模型将成为新一代预测数学/计算工具的重要组成部分，从而能够引入新一代高效、低排放的替代燃料汽车。高分辨率光学诊断和数值模拟越来越多地用于了解发动机和其他燃烧系统的潜在物理过程，并为可用于设备和系统设计的降阶模型的开发提供信息。然而，实验和数值模拟/建模之间的联系仍然有些原始。例如，非侵入式光学诊断技术需要广泛的简化和建模，以提供温度的定量值和测量辐射强度的等效比分布。与此同时，基于计算流体动力学（CFD）的湍流反应流模拟正在开发越来越复杂的光谱辐射传热模型，这些模型为直接计算与各种光学诊断技术相对应的辐射强度信号提供了理想的起点。到本项目结束时，将开发两种重要的诊断技术，用于活塞发动机等恶劣高压燃烧环境，模拟模型将扩展到直接计算与这些诊断技术相对应的辐射强度信号，并证明直接比较计算和测量的辐射强度（相对于推导量）的优势。如温度和等效比)将已完成。

1604446 - HaworthCombustion will continue to play a central role in propulsion and power generation for the foreseeable future. This includes engines for light- and heavy-duty road vehicles (cars and trucks). Aggressive fuel economy and emissions targets have been established to simultaneously reduce energy consumption and pollutant emissions, including greenhouse-gas emissions. At the same time, alternatives to petroleum-derived fuels (e.g., biofuels) are being introduced to reduce the carbon footprint of combustion-based energy systems. Predictive mathematical/computational tools are urgently needed so that engineers can optimize future engines and other combustion systems for maximum performance with minimum fuel consumption and emissions, while enabling the introduction of future sustainable fuels. These tools must include accurate representations of the key underlying physical processes. Radiative heat transfer is important in combustion systems, by virtue of their high temperatures, but has received relatively little attention to date because of its extreme complexity. This project will develop advanced radiation models that will be an important part of a new generation of predictive mathematical/computational tools, which in turn will enable the introduction of a new generation of high-efficiency, low-emissions, alternative-fuel vehicles.High-resolution optical diagnostics and numerical simulations are increasingly being brought to bear to provide fundamental insight into the underlying physical processes in engines and other combustion systems, and to inform the development of reduced-order models that can be used for device and system design. However, the connection between experiment and numerical simulation/modeling remains somewhat primitive. For example, extensive simplification and modeling are required to provide quantitative values of temperature and equivalence-ratio distributions from measured radiative intensities for nonintrusive optical diagnostics techniques. At the same time, increasingly sophisticated models for spectral radiative heat transfer are being developed for computational fluid dynamics (CFD)-based simulations of turbulent reacting flows, and these models provide an ideal starting point for directly computing the radiative intensity signals that correspond to various optical diagnostics techniques. By the end of this project, two important diagnostic techniques will have been developed/advanced for applications to harsh high-pressure combustion environments such as those in piston engines, simulation models will have been extended to directly compute radiative intensity signals corresponding to these diagnostic techniques, and a proof-of-concept of the advantages of making direct comparisons between computed and measured radiative intensities (versus derived quantities, such as temperature and equivalence ratio) will have been completed.