应能源与动力工程学院热科学与工程国际合作实验室邀请，明尼苏达大学Terrence W. Simon教授（Ernst G. Eckert Professor, ASME Fellow）将于2018年8月15日~16日来校进行学术交流并做两场学术报告，欢迎各位师生参加。
报告题目：Turbine Endwall Cooling as affected by Endwall Contouring and
Leakage and Cooling Flows
报告时间：2018年8月16日 周四 上午9:20~10:30
邀 请 人：丰镇平 教 授
报告摘要：The effects of engine-representative combustor cooling and flows introduced for sealing and cooling on endwall adiabatic effectiveness and passage temperature fields in a high pressure turbine of a gas turbine are documented. The measurements are made on a stationary linear cascade with an axisymmetrically-contoured endwall of modern engine geometry and with engine-representative approach flow thermal and fluid mechanics characteristics. The measurements give insight into mixing of combustor liner coolant and leakage and cooling flows with hot core gases ahead of and within the airfoil row. To document the effects of the various coolant streams on the passage thermal fields, cases that separate the thermal effects of the various coolant streams are compared. Reported results are thermal fields in the passage and adiabatic wall temperatures. The results give insight into mixing between the coolant streams and the mainstream passage flow. The results demonstrate that much of the endwall cooling is contributed by approach flow coolant (combustor coolant). This is an important result that has previously not been well documented.
报告题目：Enhancing Heat Transfer using MEMS Devices
报告时间：2018年8月16日 周四 下午14:30~15:30
邀 请 人：陶文铨 教 授
报告摘要：An excellent way to enhance performance of heat exchangers is to reduce the channel dimensions to the micro or nano-scale. However, there are often practical limits to shrinkage to small scales, such as blockage. In this presentation, the use of small channels for advanced air cooling of electronics is discussed, with focus on enhancement of heat transfer via a combination of active, MEMS-driven, agitators, impinging jets and passive features on the surface, micro pin fins. Agitation is by a piezoelectric-driven translating plates and diaphragms. The plates in each channel generate strong circulation near the channel walls. Translating diaphragms energize synthetic jets for impingement cooling. Micro pin-fin surfaces are fabricated on the walls by LIGA photolithography. The combined agitation, impingement and surface finning enhances heat transfer coefficients to 250% of smooth surface, without agitation, values. Discussion of the system focuses on agitation effects on heat transfer. A correlation is developed to relate Nusselt, Reynolds and Strouhal numbers for unsteady, oscillatory flow in a channel. Different regions of the agitated flow have different features: abrupt entry flow, low velocity laminar flow, and flow with strong vorticity. A single design correlation is found to fit all three regions of the channel over a range of frequencies and amplitudes of flow agitation. Also, the effects of surface features with pin fins on the wall are considered in the correlation. Finally, a prototype electronic cooling module with multiple-channels designed for cooling a 1kW chip with air is demonstrated.
Terrence W. Simon is the Ernst G. Eckert Professor of the Department of Mechanical Engineering at the University of Minnesota. He joined the University of Minnesota faculty in 1980. His major research interests include experiments, computation and visualization on heat, mass and momentum transfer in laminar, turbulent, transitional and unsteady flows, including flows through porous media and processes with phase change. Research is over the full range of length and time scales from atomic events (plasma processes) to micron scales (electronics and optics cooling) to large energy systems (engines and storage). Results are applied to plasma cutting tools and plasma flow actuators, electronics and optics, Stirling and gas turbine engines and MW-level grid energy storage systems. Professor Simon is a member of the American Society of Mechanical Engineers (including recent completion of a five-year term as the Senior Technical Editor of the Journal of Heat Transfer), the International Centre for Heat and Mass Transfer (in which he is the Vice-President and has served as Executive Committee Chair), and the American Society of Thermal and Fluids Engineers (for which he co-chaired the 2017 International Workshop on Heat Transfer).