Topical Problems of Fluid Mechanics


Institute of Thermomechanics AS CR, v.v.i.	CTU in Prague Faculty of Mech. Engineering Dept. Tech. Mathematics	MIO Université du Sud Toulon Var - AMU - CNRS - IRD	Czech Pilot centre ERCOFTAC

Hydrodynamics and Acoustics of Drop Impact
Yuli D. Chashechkin
Abstract:
Synchronous macrophotography, high-speed video filming, hydro-acoustic and air acoustic data were used to investigate physical processes initiated by the impact of free falling droplet on the surface of a fluid at rest. Planning of the experiment was carried out on the basis of fundamental equations. In the experiments, the droplets of colored water, milk, mineral oil, and seed oil fell in pure or colored water. Emphasis was placed on recording the pattern of the drop material spreading over the surface of the targeted fluid and a fine structure of acoustic signals. Traces of impacting droplets (sprays) were for the first time recorded on the surface of a submerged drop. The droplet material is concentrated on the surfaces of the cavity and crown in short thin fibers forming a regular linear or cellular patterns. The cell rows are ordered in the form of echelons separated by circular boundaries. A high frequency impact pulse and delayed secondary ones were recognized both in hydrophone and microphone signals. Generation of sound are operated by processes of formation, separations and oscillation of gas cavities with irregular forms.
Keywords:
droplet impact, sprays, matter transport, filaments, sound pulses

Fulltext: PDF DOI: https://doi.org/10.14311/TPFM.2018.006

In Proceedings Topical Problems of Fluid Mechanics 2018, Prague, 2018 Edited by David Šimurda and Tomáš Bodnár, pp. 39-46 ISBN 978-80-87012-65-9 (Print) ISSN 2336-5781 (Print)