应能源与动力工程学院侯予教授和陈双涛博士的邀请,英国Imperial College London(帝国理工学院)机械工程系副主任和研究主任R. Peter Lindstedt教授于7月10日至7月16日来我校进行学术访问,并在期间举行系列学术讲座,欢迎各位老师和同学届时参加讲座并讨论交流。
讲座安排:
讲座三:Turbulent transport and production in premixed opposed jet flames
讲座时间:2015-7-16(周四)上午09:00
讲座地点:东三楼-东汽报告厅
讲座人:R. Peter Lindstedt教授
讲座内容:
Turbulent transport and production in premixed opposed jet flames
Lu Tian and Peter Lindstedt
Abstract
The talk will discuss how fractal-grid generated (multi-scale) turbulence can be used to ameliorate classical difficulties associated with canonical laboratory experiments pursued in the opposed jet geometry and act as a bridge to practical applications. Turbulent premixed opposed jet flames typically feature large density variations coupled with an imposed pressure gradient. Both affect turbulence and scalar statistics significantly. The present work explores the modelling of such flames at the full second moment level for both velocity and scalar transport and includes extended variable density forms for redistribution/scrambling, dilatation and dissipation. The full closure includes preferential acceleration and dilatation models and is applied to the simulation of lean methane-air flames with the thermochemistry derived for the laminar flamelet regime. The encouraging agreement with experimental data for both turbulence and scalar quantities illustrates the importance of dilatation effects with the extended closure providing significantly improved agreement. However, it is also noted that the treatment of redistribution appears inaccurate near the stagnation plane. Furthermore, an analysis of the modeled scalar flux equation reveals that the treatment of ``dilatation" and the mean scalar gradient has a significant impact and that the modeling of scalar dissipation requires further attention. Comparisons for a flame close to the flammability limit suggests that the current flamelet assumption is insufficient to capture local extinction.
讲座人简介:Biography for Prof. R.P. Lindstedt
Peter Lindstedt studied at Chalmers Tekniska Högskola, Göteborg, Sweden, where he received a MEng in Chemical Engineering in 1980. At Imperial College London, Peter received a PhD from the Department of Chemical Engineering, where he also worked as a research associate. He then moved to Mechanical Engineering, where he has worked as a lecturer and reader. He was awarded the title Professor of Thermofluids in 1999. Peter served as head of the Thermofluids Division from 2000 to 2010, as Director of Research from 2003 to 2013 and as deputy head of Department from 2007-2013. In 2013, he was elected Consul for the Faculty of Engineering and Business School. He has published over 100 peer reviewed journal and conference contributions. His invited lectures include a plenary on the Chemical Complexities of Flames at the 27th International Symposium on Combustion. He is the UK Director on the International Board of the Combustion Institute (2006 to 2018). He served on the Board of Directors of the Institute of Explosions and Reactive Systems from 2002 to 2006 and as associate editor for Combustion and Flame from 2000 - 2010. He is an editorial board member of Combustion Theory and Modelling and Progress in Energy and Combustion Science. He served as the Technical Program Co-Chair (with Ron Hanson, Stanford University) for the 30th International Symposium on Combustion that also celebrated the 50th Anniversary of the Combustion Institute. Peter serves (since 2002) on the program committee for the International Workshop on Turbulent Non-Premixed flames.