应能动学院叶轮机械研究所谢永慧教授的邀请，美国 Saint Louis University航空工程技术学院Phil Ligrani教授近期来访我校，访问期间将作学术报告。Phil Ligrani教授是流动与传热领域，特别是燃机叶片强化传热方面的知名学者，目前担任ASME Transactions-Journal of Heat Transfer 的Associate Editor。

报告名称：Heat Transfer Augmentation Technologies for Internal Cooling of Turbine Components of Gas Turbine Engines

报告地点：能动学院东三楼东汽报告厅(东三甲224)

报告时间：2013年4月3日(周三) 下午 2:30

讲座内容：

To provide an overview of the current state-of-the-art of heat transfer augmentation schemes employed for internal cooling of turbine blades and components, results from an extensive literature review are presented with data from internal cooling channels, both with and without rotation. According to this survey, a very small number of existing investigations consider the use of combination devices for internal passage heat transfer augmentation. Examples are rib turbulators, pin fins and dimples together, a combination of pin fins and dimples, and rib turbulators and pin fins in combination. The results of such studies are compared with data obtained prior to 2003 without rotation influences, as summarized by Ligrani et al. Those data are comprised of heat transfer augmentation results for internal cooling channels, with rib turbulators, pin fins, dimpled surfaces, surfaces with protrusions, swirl chambers, or surface roughness. This comparison reveals that all of the new data, obtained since 2003, collect within the distribution of data obtained from investigations conducted prior to 2003, without rotation influences. The same conclusion in regard to data distributions is also reached in regard to globally-averaged thermal performance parameters,  Nuo/(f/fo)1/3 and  Nuo/(f/fo), as they vary with friction factor ratio f/fo. These comparisons, made on the basis of such judgement criteria, lead to the conclusion that improvements in our ability to provide better thermal protection have been minimal since 2003.

When rotation is present, existing investigations provide little evidence of overall increases or decreases in overall thermal performance characteristics with rotation, at any value of rotation number, buoyancy parameter, density ratio, or Reynolds number. In addition, overall thermal performance in smooth channels with rotation is affected more by Reynolds number than rotation number. Comparisons between existing rotating channel experimental data and the Ligrani et al. results show that rotation has little effect on overall thermal performance as a function of friction factor. This is largely because of the competing effects of rotation on the pressure (or trailing) sides and the suction (or leading) sides of internal channel flows. Differences in local Nusselt number ratios for pressure sides and suction sides are generally a result of increasing rotation numbers, and the rotation induced secondary flows caused by Coriolis vortices. Also considered are effects of buoyancy parameter, inlet density ratio, channel geometry, and wall heating arrangements.

专家简介：

Dr. Phil Ligrani is currently the Oliver L. Parks Endowed Chair, and Director of Graduate Programs at Parks College of Saint Louis University. His previous academic position was as the Donald Schultz Professor of Turbomachinery in the Department of Engineering Science at the University of Oxford. There, from 2006 to 2009, he was also Director of Oxford University’s Rolls-Royce UTC (University Technology Centre) in Heat Transfer and Aerodynamics. As of January 2012, Dr. Ligrani is author or co-author of more than 140 publications in archival journals, 7 book chapters, as well as approximately 92 conference publications and presentations. From 1995 to 2011, he also presented approximately 74 lectures at different institutions and establishments, including many invited lectures.

Dr. Ligrani's general research areas include convective heat transfer, laminar, turbulent and transitional flows, micro-scale flow and heat transfer, turbomachinery flows, and experimental techniques. Specific research projects focus on gas turbine heat transfer and cooling, film cooling, internal cooling, surface heat transfer augmentation, transonic flows, aerodynamic losses in turbines, effects of surface roughness, electronics cooling, micro-scale heat transfer and flow phenomena, micro-scale and miniature pump flows, protein laden flows, bio-medical particle-laden flows, and general heat transfer topics including mixed convection, conduction heat transfer, and two-phase flows. Interests also include topics in applied analytic chemistry, including Continuous SPLITT Fractionation.