Cyclic Variations of In-cylinder Multi-phase Multi-interaction Processes in Gasoline Direct Injection Engines
Professor David L.S. Hung
University of Michigan – Shanghai Jiao Tong University Joint Institute
Institute of Automotive Engineering, School of Mechanical Engineering
Shanghai Jiao Tong University, Shanghai, China
Abstract
New vehicles equipped with gasoline direct injection (GDI) engines have demonstrated high potentials in improving combustion performance and fuel efficiency. However, the cyclic variations of incylinder flow field represent a significant challenge which influence the stability and emissions of GDI engines. Elucidated by how the liquid fuel is directly injected and immediately interacts with intake air, the combustion process also depends strongly on the fuelair mixture formation inside the combustion cylinder. In this seminar, advanced optical diagnostics providing the measurements of incylinder air flow, fuelair mixing formation, and combustion processes inside an optical GDI engine cylinder are presented. The proper orthogonal decomposition (POD) analysis technique is employed to first characterize the variation of the velocity flow fields of intake air motion in the engine cylinder, and then quantitatively reveal how spray structures vary in the presence of intake air motion on a cycletocycle basis. Credited to the recent advances in laser systems, imaging hardware, and data processing algorithms, both qualitative and quantitative cyclic variations of flow and combustion inside a real engine regarding the incylinder air flow dynamics, fuel spray injection, fuelair mixture formation, flame front development, and flame structure propagation can be revealed with high temporal and spatial resolutions.
Biography
Dr. David L.S. Hung is a professor of the University of MichiganShanghai Jiao Tong University Joint Institute, with dual appointment as a professor of Institute of Automotive Engineering, School of Mechanical Engineering at SJTU. His research focuses on advanced powertrain systems, gasoline direct injection engine, fuel injection sprays and optical diagnostics. He has received research funding from agencies including China’s Ministry of Education and NSFChina. He also received numerous teaching awards for his contributions to the Joint Institute’s reform and innovation in training mechanical engineering students. He was named a Top Ten SJTU “KoGuan Professor” in 2015. Prior to working in China, he was an associate professor in the Department of Mechanical Engineering at Michigan State University. Previously he held professional positions in the US at General Motors, Delphi, and Visteon Corporations where he researched and developed powertrain components for use in advanced gasoline engines. He has attained ten US patents and published over one hundred papers in various journals and conference proceedings, including Nature Physics, International Journal of Engine Research, Fuel, SAE and ASME Transactions. He is currently an Associate Editor of the ASME Journal of Engineering for Gas Turbines and Power. Presently he serves as a vicechairman of the SAE Gasoline Fuel Injection Standards Committee. He is a recipient of numerous awards, including ASME Internal Combustion Engine Division Outstanding Speaker Award, SAE Engineering Meetings Board Outstanding Oral Presentation Awards, SAE Henry Souther Standards Award, and SAE/InterRegs Standards and Regulations Award for Young Engineers for his contributions to develop engineering standards and regulations for the global automotive industry.