Andrea Gruber
Professor of Engineering
Norwegian University of Science and Technology
Seminar Information
Engineering Building Unit 2 (EBU2)
Room 479
Seminar Recording Available: Please contact seminar coordinator, Jake Blair at (j1blair@ucsd.edu)
Modern gas-turbine technology has evolved based on the abundance of hydrocarbon fossil fuels playing a crucial and unreplaceable role in aviation, due to their high-power density, and in the stabilization of the electric grid, due to their fast response and sizeable on-demand output. In the context of the ongoing energy transition to a low-carbon society many power generation and propulsion applications must be able to operate on novel carbon-free fuels. Although fuel-flexible in principle, gas turbines can encounter serious operational issues related to flame stability and emissions because of the vastly different combustion properties of relevant carbon-free fuels, as hydrogen and ammonia, compared with conventional hydrocarbon fossil fuels. Hydrogen is highly diffusive, extremely reactive, and its turbulent burning rate exhibits a strong pressure dependence yet to be fully explained. Predicting whether hydrogen flames that are stable at atmospheric pressure will be stable at higher pressures, as needed in gas turbines, remains an unsolved fundamental problem. Ammonia is a convenient hydrogen carrier that can be partially, or fully, decomposed to hydrogen but requires careful emissions control. This lecture provides an overview of modern gas turbine technology and, based on fundamental
insights provided by first-principles direct numerical simulations and experimental evidence, introduces the main combustion-related challenges preventing the adoption of carbon-free fuels in gas turbines and proposes potential solutions.
Andrea Gruber holds a doctoral degree in Mechanical Engineering from NTNU (2006), he is Senior Research Scientist at SINTEF Energy Research and Adjunct Professor at NTNU. His research interests are in the development and application of massively parallel direct numerical simulations (DNS), a high-fidelity numerical approach to accurately predict turbulent reactive flows. Over a period of nearly two decades and in a close and fruitful collaboration with combustion researchers from Sandia Lab (Livermore, CA), Dr. Gruber has initiated the deployment of DNS on some of the research challenges related to combustion of highly reactive and non-standard fuels in gas turbines (hydrogen in particular). Pursuing industrial relevance within the framework of numerous national and European initiatives (BIGH2, NCCS, DiHI-Tech, ENCAP, DECARBit, FLEX4H2, HyPowerGT) and in close partnership with the gas turbine industry (ALSTOM, Ansaldo Energia, Baker-Hughes, Siemens Energy, Thomassen Energy), he has contributed to the fundamental understanding of key turbulence-chemistry interaction processes that play a major role in the achievement of clean and efficient power generation: design and optimization of fuel injection systems, flashback prediction and control, static and dynamic flame stabilization in conventional and staged combustors.