Implementation of thermal measurement techniques by inverse methods adapted to increasingly complex materials and/or under extreme thermal conditions, where heat transfer modes are strongly coupled.
Specificities
- Characterization of complex materials : anisotropic, porous, semi-transparent, super-insulating, etc
- High-temperature characterization of various materials: composites, metals, titanium alloys, ceramics, liquid glasses, etc
- Development of interaction models between conduction, convection and radiation in connection with experimental benches
Application sectors
- Heat transfer in building conception (fibrous insulation, super-insulating materials, etc)
- Glass and Steel processes (forming, etc)
- Thermal barriers (ceramics, composite materials, etc)
- High temperature heat recovery (ceramic absorber or heat exchanger, etc)
Keywords
- Complex materials
- High temperatures
- Thermal coupling
- Inverse methods
- Diffusivimetry
- Calorimetry
- Porosimetry
- Permeametry
Middle and high temperature thermal characterization of materials
- Thermal diffusivity measurement by Flash method:
– Continuous CO2 laser CO2 – 100 W (150 W max.)
– Vacuum tube furnace [20°C – 1800°C]
– EM-CCD infrared matrix camera
– Mounts and inverse models adapted to studied materials - Heat capacity measurement :
– 3D drop sensor with 56 thermocouples on samples of 5700 mL max.
– Heat flow differential scanning calorimeter (hf-DSC) with 20 thermocouples on samples of 450 mL max.
Thermal characterization of complex materials
- Simultaneous measurement of thermal conductivity and diffusivity :
– By three-layer flow-metric method
– By parallel hot-wire method
– Under air furnace [20°C – 1000°C]
– Mounts and inverse models adapted to studied materials - Porosity measurement by helium pycnometry
- Measurement of gas permeability
- High temperature characterization bench by Flash method
- Conductivity measurement bench for insulating materials by three-layer method in vacuum chamber
Study of the radiation absorbency of ceramic foams
Implementation of thermal characterization method of ceramic foams, more or less porous, in which the conductive-radiative heat transfer coupling is strong. Experimental measurements by Flash method [20°C – 800°C] coupled to a direct model by Finite volumes (conduction) -Monte Carlo method (radiation).
Development of an inverse analytical model for the parallel hot-wire method
Improvement of the simultaneous estimation of thermal conductivity and diffusivity between 20°C and 1000°C, with the consideration of thermal contact resistances. Variant method with 2 temperature measurements for anisotropic materials.
Complex materials
Yves Jannot
yves.jannot@univ-lorraine.fr
High temperatures
Vincent Schick
vincent.schick@univ-lorraine.fr