内燃机活塞表面的热流
日期：2023/10/27 - 2023/10/27
学术讲座：内燃机活塞表面的热流
主讲人: Marcis Jansons
时间: 2023年10月27日（周五）上午10:00-11:30
地点: 密西根学院龙宾楼中集报告厅
讲座摘要
Heat losses from reciprocating piston engines represent nearly 10% of global energy consumption. Yet, the convective heat transfer mechanism of reacting, turbulent, and pulsating boundary layers remains poorly understood. Moreover, the wall functions commonly used in numerical simulations are insufficiently accurate to predict heat losses from even non-reacting motored engine conditions. The stochastic characteristics of the turbulent boundary layer, where temperature fields are closely coupled with those of velocity, together with the steep temperature and pressure gradients at wall surfaces present challenges to analytical and numerical solutions, forming a need for experimental diagnostics for heat flux measurements from engine in-cylinder surfaces. Planar Laser Induced Fluorescence (PLIF) thermometry is used to measure the temperature profiles in the thermal boundary layer over a piston surface of a motored engine with 50 mm resolution. A thin –film infrared pyrometry technique is developed to allow the determination of surface heat flux and is simultaneously applied with the PLIF measurements to characterize the thermal boundary layer. The thin-film pyrometry technique is expanded to two dimensions, and allows the observation of heat transfer characteristics of reacting flame fronts above an engine piston, to facilitate the development of low heat loss, high efficiency engines.
主讲人简介
Dr. Marcis Jansons is an Associate Professor of the Mechanical Engineering Department at Wayne State University (WSU) in Detroit, Michigan. He teaches undergraduate and graduate courses on combustion engines, fluid mechanics and emissions formation processes, and serves as the Director of the College of Engineering's Early Engineering Program. Prior to joining Wayne State he has worked for the energy industry as an environmental engineer addressing air, soil and groundwater contamination, and as an instructor of Mechanical Engineering at the United States Coast Guard Academy. Marcis holds B.S., M.S., and Ph.D. degrees in Mechanical Engineering, earning his doctorate from Rutgers University for his work on combustion diagnostics and infrared imaging. He is a licensed Professional Engineer (P.E.). Jansons has authored over forty peer-reviewed, engine-related publications, and is a member of the Society of Automotive Engineers (SAE), the Board of Associates of the American Society of Mechanical Engineers (ASME), Internal Combustion Engine Division (ICED). He is currently teaching a course on Energy Sources and Conversion for the joint WSU-Ningbo University of Technology educational program.