Collaborative Research: NSF/DOE Advanced Combustion Engines: Radiation Heat Transfer and Turbulent Fluctuations in IC Engines - Toward Predictive Models to Enable High Efficiency

合作研究：NSF/DOE 先进内燃机：内燃机中的辐射传热和湍流脉动 - 建立预测模型以实现高效率

• 批准号: 1258613
• 负责人: Daniel Haworth
• 金额: $ 36.35万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-01 至 2017-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1258613&HistoricalAwards=false
• 关键词: Collaborative; Research; NSF; DOE; Advanced

CBET-1258613 Daniel C. Haworth The Pennsylvania State University Michael F. Modest University of California-Merced Radiation heat transfer is important in most combustion systems, by virtue of their high temperatures. In practical applications, combustion usually occurs in a turbulent flow environment, where turbulent fluctuations in composition and temperature can significantly alter the radiative transfer rates. The importance of these ?turbulence-radiation interactions? (TRI) is increasingly being recognized. Computational models that neglect radiation and/or TRI, or that treat them in an over-simplified manner, can give inaccurate predictions of important quantities including heat transfer rates, temperatures, and pollutant emissions. Radiation is known to be responsible for up to half of the in-cylinder heat losses during the combustion event in compression-ignition internal combustion engines. Accurate determination of radiative transfer rates is exceedingly difficult, requiring the solution to a five-dimensional radiative transfer equation, and further exacerbated by strong spectral variations of radiative properties. The problem reaches another level of difficulty when interactions with turbulence are considered. Consequently, radiation and TRI in engines have received little attention to date. The purpose of this research project is to quantify the extent to which radiation and TRI influence the efficiency and emissions characteristics of compression-ignition engines, and to develop predictive computational models that can be used for engine combustion system development and design. Next-generation high-efficiency engines are expected to function close to the limits of stable operation, where even small perturbations to the energy balance can have a large influence on system behavior. It is expected that radiation and TRI may be particularly important for such engines. To this end, advanced multiphase spectral radiation models and radiative transfer equation solution methods will be extended to the highly transient, high-pressure combustion environments that are representative of current and next-generation compression-ignition engines. The models will be exercised to establish conditions where radiation and/or TRI are important, and where they may safely be neglected. Outcomes of the proposed project will include new physical models and numerical strategies for radiative transfer in high-pressure multiphase systems, new physical insight into radiation and TRI in combustion environments of practical interest, and validated models that have been connected to multiple underlying computational fluid dynamics codes. Energy conversion involving turbulent combustion processes will remain important in global propulsion and power generation applications for the foreseeable future. This includes road vehicles, where ambitious near-term engine efficiency targets have been established that have the potential to significantly reduce energy and fossil fuel consumption. Radiation heat transfer is important in most combustion systems, but has received relatively little attention because of its extreme complexity. This project will provide advanced radiation models that will be part of the predictive computational tools that are required to develop high-efficiency engines. The physical insight and models that are developed will be relevant for other advanced combustion systems, including gas-turbine combustors.

CBET-1258613 Daniel C. Haworth 宾夕法尼亚州立大学 Michael F. Modest 加州大学默塞德分校 由于高温，辐射传热在大多数燃烧系统中都很重要。在实际应用中，燃烧通常发生在湍流环境中，其中成分和温度的湍流波动会显着改变辐射传输速率。这些“湍流-辐射相互作用”的重要性？ （TRI）越来越受到人们的认可。忽略辐射和/或 TRI 或以过于简化的方式处理它们的计算模型可能会对传热速率、温度和污染物排放等重要量做出不准确的预测。众所周知，压燃式内燃机燃烧过程中多达一半的缸内热损失是由辐射造成的。准确确定辐射传输速率非常困难，需要求解五维辐射传输方程，并且辐射特性的强烈光谱变化进一步加剧了这一问题。当考虑与湍流的相互作用时，这个问题就达到了另一个难度级别。因此，迄今为止，发动机中的辐射和 TRI 很少受到关注。该研究项目的目的是量化辐射和 TRI 对压燃​​式发动机效率和排放特性的影响程度，并开发可用于发动机燃烧系统开发和设计的预测计算模型。下一代高效发动机的功能预计接近稳定运行的极限，即使对能量平衡的微小扰动也会对系统行为产生很大影响。预计辐射和 TRI 对于此类发动机可能特别重要。为此，先进的多相光谱辐射模型和辐射传递方程求解方法将扩展到代表当前和下一代压燃式发动机的高瞬态高压燃烧环境。将运用这些模型来确定辐射和/或 TRI 很重要以及可以安全地忽略它们的条件。拟议项目的成果将包括高压多相系统中辐射传输的新物理模型和数值策略、对实际感兴趣的燃烧环境中的辐射和 TRI 的新物理见解，以及已与多个基础计算流体动力学相关的经过验证的模型代码。在可预见的未来，涉及湍流燃烧过程的能量转换在全球推进和发电应用中仍然很重要。这包括道路车辆，道路车辆已经制定了雄心勃勃的近期发动机效率目标，有可能显着减少能源和化石燃料的消耗。辐射传热在大多数燃烧系统中都很重要，但由于其极其复杂而受到的关注相对较少。该项目将提供先进的辐射模型，该模型将成为开发高效发动机所需的预测计算工具的一部分。开发的物理见解和模型将与其他先进燃烧系统相关，包括燃气轮机燃烧器。