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

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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."