Keynote &Plenary Speakers
22-25 July 2017 | Prague,Czech Republic
Prof. Je-Chin Han
Department of Mechanical Engineering
Texas A&M University,
College Station, Texas, USA
“Advanced Cooling in Gas Turbines for Aircraft Engine Propulsion”
Abstract: Gas turbines are used for aircraft engine propulsion, land-based power generation, and industrial applications. Thermal efficiency and power output of gas turbines increase with increasing turbine rotor inlet temperatures (RIT). Current advanced gas turbine engines operate at turbine RIT (1500°C) far higher than the yielding point of the blade material (1000°C); therefore, turbine blades are cooled by compressor discharge air (650°C). Moreover, recent research focuses on aircraft gas turbines operate even higher RIT with limited cooling air. Therefore, developments in turbine cooling technology play a critical role in increasing the thermal efficiency and power output of advanced gas turbines. To design an efficient cooling system, it is a great need to increase the understanding of gas turbine heat transfer behaviors within complex 3-D high-turbulence unsteady engine-flow environments. It is important to understand and solve gas turbine heat transfer problems under new harsh working environments. The advanced cooling technology and durable thermal barrier coatings play most critical roles for developments of advanced gas turbines with near zero emissions for safe and long-life operation. Gas turbine blades are cooled both internally and externally. Internal cooling is achieved by passing the cooling air through several rib-roughened serpentine passages inside of the blade. Internal cooling air is then ejected out through discrete holes to provide a coolant film to protect the outside surface of the blade from high-temperature combustion gas (so-called film cooling). For advanced turbine cooling, this presentation will focus on the effect of rotation on rotor blade internal cooling passage heat transfer as well as on the turbine blade outside surface film cooling including leading, trailing, tip and platform regions. The detailed film cooling distributions will be presented using the newly developed pressure sensitive paint technique. Ongoing and future gas turbine heat transfer and advanced cooling studies will be discussed.
About Prof. Je-Chin Han: Dr. Je-Chin Han is currently University Distinguished Professor and Marcus Easterling Endowed Chair Professor at Texas A&M University. He received his B.S. degree from National Taiwan University in 1970, M.S. degree from Lehigh University in 1973, and Sc.D. degree from M.I.T. in 1976, all in Mechanical Engineering. He has been working on turbine blade cooling, film cooling, and rotating coolant-passage heat transfer research for the past 40 years. He is the co-author of 220 journal papers and lead author of the book “Gas Turbine Heat Transfer and Cooling Technology”. He has served as editor, associate editor, and honorary board member for eight heat transfer related journals. He received the 2002 ASME Heat Transfer Memorial Award, the 2004 International Rotating Machinery Award, the 2004 AIAA Thermophysics Award, and the 2016 ASME IGTI Aircraft Engine Technology Award. He is a Fellow of ASME and AIAA.
Prof. Anh Dung NGO
École de technologie supérieure (U. du Québec), Canada
About Prof. Anh Dung NGO: B.Sc. A in Mechanical Engineering (É. Polytechnique, Canada), M.Sc. in Wood technology (U. Laval, Canada), Ph.D. in Mechanical Engineering (Concordia U., Canada). Professor NGO spent 18 years in industry as engineer and in governmental agency first as engineer and later as chief officer of the Occupation Safety Division at the Prevention Branch of the Quebec Occupational Health and Safety Commission before joining the university in 1991. He was the Chairman of the Mechanical Engineering Department from 1999 to 2004. He is the founder of two research groups, one in Occupational Safety and one in Composite Materials. He is also the editor of the Proceeding of the EIGHTH JOINT CANADA-JAPAN WORKSHOP ON COMPOSITES and author of sixty scientific papers and technical reports on Composites Materials and Occupational Safety.
Orleans University, France
About Prof.Dashnor Hoxha: After obtained an engineer degree from Polytechnic Univeristy of Tirana and a Bachelor in Physics form Natural Science Faculty of Tirana, Albanie in 1991, I was awarded Mc. S and Ph. D in Geomechanics Hydrosystems and Structures from National Polytechnic Institut of Lorraine (INPL) France in 1998. I worked for ten years in the research and developing industry before joining the University of Orleans as Head of Sustainables Constructions Division in 2007. I work actually in the Laboratory of Pluridisiplinary Research in Engineering Systemes, Mechanics and Energy (PRISME) and I teach as Professor in Polytechnic School of Orleans. I published more than 34 papers in refereed international journals and 45 papers in conferences and 4 book chapiters and I have been involved in many international conferences as Technical Chair and tutorial presenter.
Prof. Simon Barrans
University of Huddersfield, United Kingdom
"Mechanical design of rotors for permanent magnet high speed electric motors for turbocharger applications"
Abstract: Realisation of electrically boosted turbochargers requires electric motors capable of operating at very high speeds. One concept for such motors packages the electric motor within the bearing housing and uses a permanent magnet rotor. A significant challenge with such a rotor system is ensuring its structural integrity when subjected to high inertial forces and substantial, changing temperature gradients. Typically in such rotors, the two half cylinders of the rare earth permanent magnet are sandwiched between an inner and outer sleeve. The inner sleeve is then attached to the shaft of the turbocharger rotor assembly. The outer sleeve is a shrink fit onto the magnet, the objective being to ensure that the magnet always remains in compression in the circumferential direction. Whilst it is possible to model such systems numerically, such models are an inefficient tool for design optimisation. Analytical models of such rotors currently appear to be restricted to the magnet assembly and outer sleeve with no consideration being given to the impact of the inner sleeve and shaft.
In this paper an analytical model is developed which allows the stresses in the rotor to be determined taking into account interactions between the shaft and inner sleeve, the inner sleeve and the magnet, and the magnet and outer sleeve. The model accounts for the effect of any designed interference between the parts as well as inertial and thermal loads. Both the centre of the rotor where generalized plane strain may be assumed and the end of the rotor where plane stress is present are considered. The validity and limitations of this analytical model are then investigated by comparison with numerical models.
Having developed the model, the constrained optimisation problem of selecting component dimensions and levels of interference is investigated. Constraints on the optimisation include:
- Stresses generated within the individual rotor components to ensure that material capability is not exceeded.
- Stresses generated at the interfaces between the rotor components to ensure that sufficient contact force remains to prevent torsional slip between parts under load. Where rotor parts are fixed together by adhesive, the capability of the adhesive layer must also be considered.
- Constraints placed on the magnet size and geometry by electromagnetic considerations.