EXP 1-4 Introduction

Axisymmetric drop impact dynamics on a wall film of the same liquid

Front Page

Introduction

Review of experimental studies

Description

Experimental Set Up

Measurement Quantities and Techniques

Data Quality and Accuracy

Measurement Data and Results

Introduction

Droplet impact onto wetted surfaces is of pertinence to many technical applications such as internal combustion engines, icing on plane wings and spray coating technologies to name a few. Immediately after the impact, the droplet expands radially along the surface. If the impact kinetic energy is sufficiently high, an upward growing crown is generated with detachment of secondary droplets. For the cases considered here, splashing is absent and the drop-film interaction is axisymmetric. The two-phase flow is laminar and its dynamics is governed by an interplay between inertial, viscous and capillary forces. The formation and expansion of the crown and the associated flow field in both phases are illustrated in Fig. 2 which shows results of accompanying axisymmetric numerical simulations. The experiment provides data for the time evolution of the three characteristic dimensions of the crown forming during the drop-film interaction, namely the height of the crown and its top and base radius.

Fig. 2: Snapshots of phase distribution and velocity field from numerical simulations (moderate drop impact velocity 2 m/s).

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Contributed by: Milad Bagheri, Bastian Stumpf, Ilia V. Roisman, Cameron Tropea, Jeanette Hussong, Martin Wörner, Holger Marschall — Technical University of Darmstadt and Karlsruhe Institute of Technology

Front Page

Introduction

Review of experimental studies

Description

Experimental Set Up

Measurement Quantities and Techniques

Data Quality and Accuracy

Measurement Data and Results

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