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SUMMARY:MechE Seminar: Understanding the fatigue-induced damage in hydraul
 ic machines to secure their flexible operation
DTSTART:20230706T090000
DTEND:20230706T100000
DTSTAMP:20260929T053346Z
UID:6ae8d8be2a61fc08ef5c839ec09eb6b5678fb0fb28e4a56efae6c3e9
CATEGORIES:Conferences - Seminars
DESCRIPTION:Dr. Elena Vagnoni\, Technology Platform for Hydraulic Machines
 \, EPFL\nAbstract: The increasing flexibility needs of modern power system
 s represent a major concern for the safe operation of hydropower assets. E
 xtended operating ranges and frequent start-ups and stops are direct conse
 quences of enhanced provision of regulating services to the power grid and
  the main cause of performance degradation\, lifetime reduction and failur
 es that common practices cannot predict. To overcome this hurdle\, the sem
 inar discusses how to assess the mechanical stresses leading to fatigue in
  Francis and Pelton runners through experimental investigations employing 
 strain gauges measurements on reduced-scale models. These measurements are
  leveraged to develop a predictive method of the fatigue-induced damage co
 nsidering the full operating range of the hydraulic machine\, as well as s
 evere transients’ operations such as the start-up sequence. Since the me
 chanical stresses’ distribution is inherent to the geometrical propertie
 s of the hydraulic machine\, two different methodologies are developed: a 
 physics-informed neural network for Francis-type runners\, and a reduced-o
 rder analytical model for Pelton runners. The forecasts of both predictive
  models show a good agreement with the experimental measurements represent
 ing a leap in predictively understanding the mechanical stresses leading t
 o fatigue-induced damage. Furthermore\, the seminar shows how to formulate
  a complex optimization problem to define the optimal start-up trajectory 
 that minimizes the fatigue-induce damage cost\, while preserving a fast re
 sponse-time of the hydraulic machine. The findings show that the start-up-
 induced fatigue in both hydraulic machines can be significantly reduced. A
 s an example\, variable-speed Francis turbines can experience a runner fat
 igue reduction of almost 90% by defining a start-up trajectory that avoids
  operating conditions causing higher stresses on the runner blades.\n\nBio
 graphy: Dr. Elena Vagnoni is currently the head of the research projects g
 roup at EPFL Technology Platform for Hydraulic Machines and lecturer for t
 he EPFL Mechanical Engineering Section. Her research interests focus on th
 e experimental investigation\, numerical simulation and predictive modelli
 ng of the hydraulic machines behaviour to improve the hydroelectric units
 ’ exploitation in conventional and unconventional hydropower schemes.\nS
 he graduated with honours in Mechanical Engineering from the Politecnico o
 f Milan (Italy) in 2013\, and she obtained her Ph.D. in Mechanics at EPFL 
 in 2018. Before her current position\, she was a research assistant fellow
  at Johns Hopkins University (US)\, a postdoctoral researcher at EPFL\, an
 d a SNSF-fellow guest scientist at NTNU (Norway). She is the Swiss expert 
 for the Annex IX of the International Energy Agency (IEA) Hydropower Techn
 ology Cooperation Programme and Vice-Coordinator of the European Energy Re
 search Association (EERA) joint program Hydropower.
LOCATION:MXF 1 https://plan.epfl.ch/?room==MXF%201 https://epfl.zoom.us/j/
 66082956091
STATUS:CONFIRMED
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