Experimental investigation into deposition/splashing behavior of droplets impacting vibrating surface

An experimental investigation is performed into the behavior of ethanol droplets impacting on a vibrating stainless steel surface. In characterizing the impact behavior, the dimensionless kinetic energy of the droplet prior to its impact on the surface is represented by the original Weber number ( W...

Full description

Bibliographic Details
Main Authors: Tong-Bou Chang, Rong-Horng Chen
Format: Article
Language:English
Published: SAGE Publishing 2017-11-01
Series:Advances in Mechanical Engineering
Online Access:https://doi.org/10.1177/1687814017730004
Description
Summary:An experimental investigation is performed into the behavior of ethanol droplets impacting on a vibrating stainless steel surface. In characterizing the impact behavior, the dimensionless kinetic energy of the droplet prior to its impact on the surface is represented by the original Weber number ( We ). Meanwhile, the dimensionless relative impact kinetic energy of the droplet as it impacts the vibrating surface, and thus undergoes a change in its relative impact speed, is represented by the relative Weber number ( We r ). Impact experiments are performed for various values of the original Weber number We and vibration frequency f. The impact behavior in each case is classified as either post-spreading deposition or crown splashing. It is shown that for a static (non-vibrating) surface, the critical Weber number for the generation of splashing is We c  = 400. Furthermore, for a given impact speed and vibration frequency, if no splashing occurs without vibration but splashing takes place after vibration, the difference between the original Weber number ( We ) and the critical Weber number ( We c ) is proportional to the additional impact Weber number provided by the vibrating surface, that is, ( We r  −  We c ). For a given relative impact speed, a higher vibration frequency ƒ results in a greater relative impact distance during splashing and a larger effective impact energy. Overall, the experimental results show that the relation between We and We r for the generation of splashing is given as We = ( − cf / ( 1 − cf ) ) W e r + ( 1 / ( 1 − cf ) ) W e c , where c = 3 . 45 × 10 − 4 .
ISSN:1687-8140