Research activities

Phase change heat transfer

ContextAll studies developed within this research group focus on two-phase heat transfer (liquid-vapor or solid-liquid) and their applications to thermal systems, in particular two-phase passive cooling systems. All of this research work is conducted both experimentally and theoretically, with a good balance between these two approaches. The studies are both global for sizing systems and local to improve understanding of the fundamental mechanisms behind their operation.Objectives

  • Develop knowledge about the fundamental mechanisms of phase change in transient and steady state
  • Improve thermal exchanges by phase change (by structuring the walls, confining the fluid, applying an electric field, etc.)
  • Understand and master the phenomena governing passive two-phase cooling systems
  • Develop and characterize innovative capillary structures; implement materials adapted to the functions required by passive two-phase systems
  • Understand and control phenomena governing drying operations

Scientific skills

  • Analysis of the phenomena of evaporation and condensation in the presence of thin films, in capillary geometries, with or without an electric field, and possibly in the presence of thermo-hydraulic or thermo-capillary instabilities notably with a metrology of local visualization of the interfaces liquid vapor (fast camera, infra-red camera, confocal microscope, near-field telescope, ...)
  • Analysis of the physical phenomena of nucleate boiling (nucleation, magnification, detachment, coalescence), under normal or low pressure, with or without an electric field, on ultra-smooth or micro / nano structured surfaces
  • Analysis of the physical phenomena of boiling and condensation in confined geometries, on wetting or non-wetting surfaces
  • Development of analytical and numerical models for dimensioning or describing the operation of different types of passive two-phase systems (conventional heat pipes, oscillating heat pipes, two-phase loops, PCM thermal interposers, etc.)
  • Development of test benches to fill (vacuum techniques, degassing of fluids) and to characterize these systems (adapted thermal metrology)
  • Development of test benches and numerical models to analyze coupled phenomena during drying operations (vacuum or sweeping)

Some international collaborationsDuke University (Durham, NC, USA), ITP Ekaterinburg (Russia), IIT Kanpur (India), Trinity College Dublin (Ireland).Some national collaborationsCEA LEGI/LITEN/SBT (Grenoble), CEA/DEN, Pprime (Poitiers), IEMN (Lille), IMFT (Toulouse), IUSTI (Marseille), Laboratoire Hubert Curien (St Etienne), Laplace (Toulouse), LPMCN (Lyon), MATEIS (Lyon), AMPERE (Lyon), IPC (Oyonnax), CTIF (Sèvres)Recent industrial partnershipsAir liquide, Airbus, ARRK Shapers, ATHERM, Calor, HEF, Innomolds, Liebherr, Orano, Peugeot, Sanden, SAFE Metal, Safran, STMicroelectronics, Thalès Avionics, Thalès Communication, Valeo