Florian Chavagnat

Dr. Chavagnat is currently a Research Scientist affiliated with Center for Advanced Nuclear Energy Systems group in the Department of Nuclear Science and Engineering at MIT.

He earned a Master’s degree in Energy Engineering from the INSA Rouen-Normandie followed by a Ph.D. in Nuclear Science and Engineering from MIT, specializing in Multiphase Flow, Single-Phase and Two-Phase Heat Transfer.

His primary focus is on experimental heat transfer research within the Reactor Engineering and Design Laboratory.

Boiling studies for nuclear reactor applications

Comprehensive experimental studies are conducted to characterize boiling phenomena relevant to nuclear reactor cooling and to assess the thermo-hydraulic performance of accident-tolerant fuel cladding surfaces and other innovative surface designs. A broad range of prototypical light water reactor (LWR) conditions is investigated, spanning steady-state operation to rapid reactivity-initiated accident (RIA)-type transients, with pressures, temperatures, and mass flow rates extending up to pressurized water reactor (PWR) conditions. The phenomenological understanding derived from these experiments aims to support the development of next-generation, high-fidelity boiling models for nuclear reactor design and safety analysis.

Boiling studies for space application

The mechanisms governing boiling in cryogenic fluids remain poorly understood, despite their critical and growing role in space rocket propulsion systems. This work investigates the fundamental physics of contact-line evaporation, liquid conduction, bubble dynamics, and boiling crisis in cryogenic fluids using high-resolution, non-intrusive diagnostic techniques. Experiments are conducted under both Earth-gravity and microgravity conditions, leveraging parabolic flight campaigns to isolate gravity-dependent effects. The resulting experimental data and theoretical insights support the development and optimization of in-space cryogenic fuel management (CFM) technologies, with the objective of reducing propellant losses, lowering mission costs, and extending spacecraft operational range.

Development of New Measurement and Analysis Techniques for Probing Boiling Fluids

Novel optical diagnostic techniques based on visible and infrared imaging are coupled with data-processing approaches leveraging machine learning to efficiently acquire, process, and analyze large volumes of experimental data. These data are then used for the development and validation of mechanistic boiling models.