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The laws of nature are but the mathematical thoughts of God.
Euclid
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Spray impact leads to a creation of a fluctuating liquid layer on a
wall. The flow in this layer looks very chaotic. This table is an attempt to
classify some possible events which can happen during spray impact onto a
cold wall: Cascade of breakups of small drops, drop deposition, corona
splash, non-symmetric splash after inclined impact, prompt splash, corona
breakup into jets, Faraday jets, drops interactions, capillary waves, film
dewetting due to drop impact, film instability leading to the creation of
big drops on the substrate, jets appearing during very dense Diesel spray
impact.
We are going to complete the table as soon as new phenomena will be
discovered.
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Drop impacting onto a dry rigid substrate creates a radial flow in
the lamella. The lamella is bounded by a rim formed due to capillary
forces. If the substrate is non-wettable, the rim recedes, sometime leading
to rebound.
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Drop impacting onto a liquid film also creates a radial flow in the
“inner region” of the film. This flow interacts with the outer undisturbed
film. If the inertia is high enough, this interaction leads to the creation
of a crown-like uprising sheet. This free sheet is bounded by a rim, formed
by capillary forces. At some conditions (above the splashing threshold) the
rim centerline bends leading to the formation of cusps, jets and secondary
droplets.
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Drop breaks up in a strong, non-stationary gas flow. Several mechanisms of drop breakup are
distinguished:
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Bag break-up
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Shear break-up
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Stretching/thinning
break-up
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Catastrophic
break-up
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High velocity gradients and instationary viscous streams can also
destroy the drop. The break-up mechanisms are subdivided into
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Capillary break-up
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Necking
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End-pinching
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Tip streaming
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Binary drop collision leads to the creation of a radially expanding
free liquid sheet, bounded by a rim. This rims is formed by surface
tension. At some instant the rim recedes, merges and creates a stretching
free jet. This jet is bounded by two globes. The globes are also formed by
capillary forces.
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