• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.8
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• pp.647-654
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• 2012

Supercooled large droplet issues in aircraft icing have been continually reported due to the important safety considerations. In order to simulate the impingement behavior of large droplets, a two-dimensional and compressible Navier-Stokes code was developed to determine the flow field around the test model. Also, the Eulerian-based droplet impingement model including a semi-empirical approach for the droplet-wall interaction process and droplet break-up was developed. In particular, the droplet-wall interactions were considered as numerical boundary conditions for the droplet impingement simulation in the supercooled large droplet conditions. Finally, the present results were compared with the experimental test data and the LEWICE results. The droplet impingement area and maximum collection efficiency values between present results and wind tunnel data were in good agreements. Otherwise, the inclination of collection efficiency of the present result is over-predicted than the wind tunnel data around a lower surface of the NACA 23012 airfoil.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.6
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• pp.633-638
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• 2012

The maximum spreading is the maximum extent to which a drop can spread after impacting on a surface. It is one of the crucial factors determining the spraying performance in many applications. In this study, the existing maximum spreading models for a Newtonian liquid droplet impacting on a dry solid surface were reviewed and compared with the experimental results over the ranges of $4{\leq}Re{\leq}11700$, $23{\leq}We{\leq}786$, and $37.9^{\circ}{\leq}{\theta}_s{\leq}107.1^{\circ}$. The surface wettability was found to have only a minor influence on the maximum spreading, compared to the liquid viscosity and impact velocity. Among the models tested, the Roisman (2009) model showed the best agreement with the experimental results, matching 80% of the measured data within ${\pm}5%$.