Chemical Quenching Studies Using Microscopic PLIF
Speaker: Yuji Suzuki, University of Tokyo, Japan
Department: Mechanical & Aerospace Engineering
Location: Engineering Quadrangle J223
Date/Time: Monday, November 18, 2013, 2:00 p.m. - 3:00 p.m.
Detection of near-wall radical distribution is crucial to study chemical quenching mechanisms on solid walls. To give an insight into the wall material effect on the chemical quenching phenomena, a methane-air premixed flame formed in narrow quartz channels with different wall surfaces is investigated. In the present study, alumina and SUS321/Inconel600 thin films 100~150 nm in thickness are deposited on polished quartz substrates by using atomic layer deposition (ALD) or vacuum arc plasma gun. With the present configuration, equivalent thermal boundary condition is achieved for different wall materials. Microscopic OH-PLIF and numerical simulation with detailed reaction mechanisms are employed to examine interaction between the gas-phase and surface reactions. When the wall temperature is higher than 1073 K, the wall chemical effect starts to take over the thermal effect. It is shown through the PLIF measurements that OH* mole fraction near the wall surface is significantly changed over different wall surfaces. By using a radical quenching model, the initial sticking coefficient S0 associated with radical adsorption is evaluated for different surfaces. A series of numerical simulation is also made to examine the effect of S0 on the methane-air flame in micro channels. It is found that the wall chemical effect becomes of great importance for the gross flame characteristics such as the initiation temperature of the chain reaction and the heat release rate.
Prof. Yuji Suzuki received the B.S., M.S., and Dr.Eng. degrees in mechanical engineering from the University of Tokyo, Tokyo, Japan, in 1987, 1989, and 1993, respectively. After serving as an assistant professor at the Nagoya Institute of Technology, he joined the Graduate School of Engineering, the University of Tokyo. He is currently with the Department of Mechanical Engineering, the University of Tokyo, as a Professor and Department Head. He serves as an Editorial Board Member of JMM. He also served as a Vice Chair of JSME Micro-Nano Science & Technology Division and a steering member of IEEE MEMS Conference. His research interests include micro energy conversion such as microscale combustion, optimal design/control of micro heat and fluid flow, and MEMS-based energy harvesting.