力学系与湍流国家重点实验室学术报告6.15( 报告人：Yanbao Ma)
发布时间: 2010-06-11 01:35:00
SEMINAR SERIES
北京大学工学院 
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力学与空天技术系
湍流与复杂系统国家重点实验室
报告人 Yanbao Ma
School of Engineering
University of California, Merced
报告内容摘要
Computational fluid dynamics (CFD) has become a very powerful tool in studying multi-physics flow phenomena in different scales ranging from hypersonic flows for design of high-speed transportation vehicles to microfluidic flows for design of multi-functional microfluidic systems in bioapplication.
A computational code was developed by combining a fifth-order shock-fitting scheme with additive semi-implicit Runge-Kutta methods to investigate the receptivity process with chemical reactions in hypersonic flows. Receptivity is the process how environmental disturbances enter the supersonic/hypersonic boundary layer and induce boundary-layer instabilities. The receptivity process is the first step of laminar-turbulence transition. The receptivity mechanisms were revealed in this study which would significantly facilitate active control on laminar-turbulent transition for optimal design of high-speed vehicles.
Microfluidic systems offer the potential for both fundamental chemical/biochemical/biologic analysis and practical clinical diagnostics. A bio-concentrator was designed to substitute the centrifuge in bioprocess to separate and concentrate target bacteria. AC dielectrophoretic force was employed to manipulate the movement of micro scale bacteria for separation and concentration. The geometric design of the bioconcentrator was optimized by using computational physics. A novel micro mixer was modeled and optimized by using numerical simulations. Efficient mixing was achieved by using pressure disturbances, which was proved by both numerical simulations and experiments.
报告人简介
Dr. Ma obtained his Ph.D. in Fluid Mechanics from University of California at Los Angeles in 2004. After receiving his Ph. D. degree in mechanical Engineering from UCLA, he joined Micro Systems Lab of UCLA and worked on micro-fluidic systems for biological analysis and biomedical diagnosis. In 2009, he joined University of California at Merced as an assistant professor. His broad research interests revolve around the areas of multi-scale, multi-physics flow phenomena including macro-scale aerodynamics, hydrodynamics, micro-and nano-scale fluidic systems. In his doctoral research, he investigated the receptivity and stability of high-speed boundary-layer flows using both direct numerical simulation and linear stability analysis. Currently, he is working on microfluidic systems and biomolecular sensors for infectious bacteria detection, cancer diagnosis, metabolomic analysis, bioterrorism reagents detection, and bioreactor design for stem cell engineering.
主持人：史一蓬
时 间：6月15日（周二）下午3:00
地 点：力学楼434会议室
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