NSF/DOE Advanced Combustion Engines: Development of a Dynamic Wall Layer Model for LES of Internal Combustion Engines

CBET 1258609PI（机构）：Ihme（斯坦福大学），sick /Reuss（密歇根大学），Fajardo（密歇根大学）美国)基于物理的内燃机近壁流体运动和传热预测模型的开发和实施为内燃机提供了一种可行的技术。该模型基于基础的高保真仿真和最先进的实验，为实现稀薄燃烧和低温燃烧（LTC）发动机提供了新的能力。与火花点火式节气门汽油发动机相比，燃油经济性提高了12%，预计可达20%。使用类似柴油的燃料，LTC发动机的收益预计将超过10%。近壁面流动对内燃机的传热和近壁面化学反应性具有重要的影响，但人们对近壁面流动还没有完全了解。这些过程反过来又影响LTC发动机的稳定性，从而影响其运行效率和污染物的形成。本文将进行详细的数值模拟和高速激光成像实验，以获得对缸内近壁结构的基本认识，并建立用于大涡模拟的壁函数模型。将在光学发动机中进行验证研究，以证明该模型在广泛的操作模式和条件下的适用性和性能。整合到这项研究的是与工业和国家实验室的几项合作活动，以加速基础和应用工作的进展。研究工作被整合到一系列创新学习和推广活动中，这些活动有助于招聘和教育科学和工程工作人员。本科生、研究生研究助理和博士后研究人员都参与了这个项目的各个层次。几个教育和推广活动被整合到这个项目中，包括通过“工程管道”计划招募高中生和参加内部研究交流计划的机会。这些独特的学习和拓展元素符合密歇根大学工程学院的使命，即至少有一半的本科生获得国际经验，作为其学院教育的一部分。研究数据通过发动机燃烧网络向公众发布。美国国家科学基金会的立法和公共事务办公室以及“全民科学”和“生活科学”等网站为非专业观众制作和传播文章、视频和其他媒体提供了便利。

CBET 1258609PI (Institution): Ihme (Stanford U), Sicke/Reuss (U Michigan), Fajardo (W. Mich. U.) The development and implementation of a physics-based predictive model for near-wall fluid motion and heat transfer in internal combustion engines provides an enabling technology. The model, derived from fundamental, high-fidelity simulations and state-of-the art experiments, leads to new capabilities for the implementation of lean-burn and low-temperature combustion (LTC) engines. 12% fuel economy gains over throttled spark-ignition gasoline engines were demonstrated and up to 20% are expected. Operated on Diesel-like fuels, gains for LTC engines are expected to be in excess of 10%. The near-wall flow is not fundamentally understood for in-ternal combustion engines, but has leading impact on heat transfer and affects chemical reactivity near walls. These processes in turn affect the stability and thus the efficiency of LTC engine op-eration and pollutant formation. Detailed numerical simulation and high-speed laser imaging ex-periments will be conducted with the objective of obtaining fundamental understanding about in-cylinder near-wall structure and developing a wall-function model for large-eddy simulations. Validation studies in optical engines will be performed to demonstrate the applicability and per-formance of the model for a wide range of operating modes and conditions. Integrated into this research are several collaborative activities with industry and national laboratories to accelerate progress at both the fundamental as well as the application end of the work.The research work is integrated into a range of innovative learning and outreach activities that contribute to recruiting and educating the scientific and engineering work force. Undergraduate, graduate research assistants, and postdoctoral researchers are involved at all levels with the pro-ject. Several educational and outreach activities are integrated into this project, including the re-cruitment of high-school students through the "Engineering Pipeline" program and opportunities to participate in internal research exchange programs. These unique learning and outreach ele-ments are in line with the University of Michigan's College of Engineering's mission to have at least half of the undergraduate students gain an international experience as part of their College education. Research data are disseminated to the public via the Engine Combustion Network. Production and dissemination of articles, videos, and other media for lay audiences are facilitated through NSF's Office of Legislative and Public Affairs and venues such as "Science for Every-one" and "LiveScience.com."