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Dynamics of impacting droplets |
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Secondary atomization within the various boiling regimes
In this part of the work, image analysis techniques are combined with measurements using a phase Doppler instrument to quantify the effect of different parameters, namely liquid properties, impact angle and surface topography, in secondary droplet characteristics. Combination of both techniques allows studying the temporal evolution of secondary droplet size and velocity distributions over extended distributions, within a wide range of droplet diameters, from 5mm up to few millimetres, thus covering the various boiling regimes. The figure illustrates the SMD evaluated from the extended pdf’s of the secondary droplets resulting from the impact of water and isooctane drops onto a stainless steel surface at similar conditions, within the nucleate and film boiling regimes. The SMD is evaluated from the extended size distributions obtained with the combination of phase Doppler measurements and image analysis, for various time instants and different impact angles, a.
Bubble Boiling
Film Boiling
This study is performed in collaboration with the Thermofuids and Heat Transfer Group – THT from the Engineering Faculty of Bergamo University.
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