Summer Heat Transfer Conference

Hyatt Regency Bellevue, Bellevue, Washington

July 9 - 12, 2017

Max Jakob Award Lecture


2017 Max Jakob Memorial Award Lecture

Je-Chin Han

Texas A&M University
Mechanical Engineering Department
College Station, Texas, USA

Heat Transfer and Advanced Cooling in Gas Turbines

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 turbines 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 gas turbines operate even higher RIT with reduced 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-turbulent unsteady turbomachinery-flow conditions. It is important to solve gas turbine heat transfer problems with advanced cooling concepts under harsh working environments. The advanced cooling technology and durable thermal barrier coatings play most critical roles for developments of modern 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 serpentine channels 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 flow. For advanced turbine cooling, this presentation will focus on heat transfer augmentation in the internal cooling passage with ribs, impinging jets, dimples, and pin-fins, heat transfer in rotating channel flows, film cooling in unsteady high free-stream turbulent flows and turbine edge-region cooling includes leading-edge, trailing-edge, blade-tip, and end-wall regions. The detailed film cooling distributions will be presented using the newly developed pressure sensitive paint heat-mass transfer analogy technique. Ongoing and future gas turbine heat transfer research and advanced cooling trends will be presented and discussed.

Dr. Je-Chin Han is currently University Distinguished Professor, Marcus Easterling Endowed Chair Professor and Director of Turbine Heat Transfer Laboratory at Texas A&M University. Born in Taiwan, Han received his B.S. degree from National Taiwan University in 1970. He came to the United States to obtain his M.S. degree from Lehigh University in 1973, and Sc.D. degree from M.I.T. in 1976, all in Mechanical Engineering. After 4 years working in the industry as an engineer, he has been a faculty member at Texas A&M University since 1980. He was a Research Fellow at Wright-Patterson Air Force Base, NASA-Glenn Research Center and United Technologies-Pratt & Whitney Turbine Center.

Dr. Han is well known for pioneering and excellent studies in high-temperature turbine blade cooling research that has greatly impacted the modern development of high-efficiency gas turbines for both aircraft and land-based power generation applications. His works are generally basic convection but relate closely to turbine blade internal heat transfer enhancement and external film cooling applications for NASA, DOE, General Electric, Pratt & Whitney, Siemens, Honeywell, and Solar Turbines for the past 37 years. His pioneering work in angled-rib turbulence promoters has replaced earlier designs and become a standard and has had a lasting impact in the way that gas turbine companies design advanced turbine blade cooling systems. His original work in Coriolis force and rotating buoyancy force effects on coolant passage heat transfer using a novel and excellent rotating facility have resulted in the design of more efficient turbine rotor blades. His fundamental study on film cooling under unsteady high free-stream turbulence conditions has had a huge impact on turbine blade film cooling design. He performed an excellent series studies with innovative techniques he helped to develop and popularize including liquid crystal visualization of surface temperature and pressure sensitive paints providing a mass transfer analogy to heat transfer applicable to gas turbine geometries.

Professor Han has supervised 32 M.S., 45 Ph.D. students, and 12 Post-Doctoral Research Associates, and hosted 10 International Visiting Scholars. Han is the author or co-author of approximately 480 technical publications including 225 refereed journal papers, 21 articles appearing in book chapters, and 235 refereed conference papers, and 6 United States patents. His publication has received more than 16,300 Google Scholar Citations with 66 h-index and 232 i10-index. Han has published an influential book "Gas Turbine Heat Transfer and Cooling Technology" in 2000 which describes many cooling techniques that have won wide acceptance in the gas turbine industry and a graduate-level text book "Analytical Heat Transfer" in 2011.

Dr. Han has been invited to more than 100 seminars, including more than 35 invitations to present keynote papers at various national and international conferences. He has served as chair of the ASME K-14 Gas Turbine Heat Transfer Committee (2004-2006) and several Heat Transfer Honors and Awards Committees (2005-2006, 2008-2010). He has served as chair on a number of conferences and as the session organizer, chair or topical organizer for more than 70 ASME, AIAA, and international conference technical sessions. He has served as an editor of the International Journal of Rotating Machinery since 1994, as an associate editor of the ASME Journal of Heat Transfer (1997-2000), Journal of Turbomachinery (2004-2013) and Journal of Engineering for Gas Turbines and Power (2004-2007), and for the AIAA Journal of Thermophysics and Heat Transfer (2004-2015), an Honorary Editorial Advisory Boards Member for the International Journal of Heat and Mass Transfer since 2005 and for the Frontiers in Heat and Mass Transfer since 2010. He received the 2002 ASME Heat Transfer Memorial Award, the 2004 International Rotating Machinery Award, the 2004 AIAA Thermophysics Award, the 2007 ASME K-14 Warren Rohsenow Prize, and the 2016 ASME IGTI Aircraft Engine Technology Award. He is a Fellow of both ASME and AIAA.

CITATION: For lasting contributions in pioneering advanced gas turbine blade cooling research, particularly in convective heat transfer augmentation, heat transfer in rotating channel flows, and film cooling in unsteady high turbulent flows.