Experimental investigations have been conducted for quenching of a hot rotating cylinder with initial temperature of about 500-600°C by a subcooled planar water jet. An original experimental device allowing the estimation of the local boiling curves in the case of a static surface and of a moving surface has been designed. Heat fluxes were measured on both side of the axis of the jet until a reduced distance x/ of 18, in a range of subcooling from 10 to 83K, for a jet velocity from 0,8 to 1,2 m/s and for a velocity flow-surface ratio (u S /u j) from 0.5 to 1.25. In the case of static surface, the measurements confirmed the existence of a "shoulder of flux" in the stagnation zone of the jet. In the case of a moving surface, the maximum of heat transfer (for a given regime) is moving during the cooling time from downstream (film boiling regime) to upstream (forced convection).

This work is an experimental study aiming at characterizing the heat transfers induced by the impingement of water droplets (diameter 80-180 lm) on a thin nickel plate heated by electromagnetic induction. The temperature of the rear face of the nickel sample is measured by means of an infrared camera and the heat removed from the wall due to the presence of the droplets is estimated using a semi-analytical inverse heat conduction model. In parallel, the temperature of the droplets is measured using the twocolor Laser-Induced Fluorescence thermometry (2cLIF) which has been extended to imagery for the purpose of these experiments. The measurements of the variation in the droplet temperature occurring during an impact allow determining the sensible heat removed by the liquid. Measurements are performed at wall conditions well above the Leidenfrost temperature. Different values of the Weber numbers corresponding to the bouncing and splashing regimes are tested. Comparisons between the heat flux removed from the wall and the sensible heat gained by the liquid allows estimating the heat flux related to liquid evaporation. Results reveal that the respective level of the droplet sensible heat and the heat lost due to liquid vaporization can vary significantly with the droplet sizes and the Weber number.

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