Modulation of droplet trajectory using oscillating electric fields
File(s)
Published version
Author(s)
Lawson, Thomas H
Giusti, Andrea
Type
Journal Article
Abstract
The use of sinusoidal electric forces to modulate the location of charged fuel droplets in a channel flow configuration is studied as a potential technology to achieve control over fuel–air mixing. Trajectories of a single non-evaporating droplet are first investigated using both an analytical solution based on a linearised drag model and results obtained with a non-linear model for the drag force. Non-dimensional quantities are also introduced to generalise the problem and provide useful information for technology development. Then, the effects of oscillating electric fields on the dispersion and stratification of fuel vapour are investigated using large-eddy simulations. Kerosene is used as fuel, which is relevant for aviation applications. Results show that oscillating electric fields perpendicular to the bulk flow can significantly enhance the spreading of both droplets and fuel vapour, an effect that is more evident with decreasing angular frequency of the oscillation and decreasing flow bulk velocity. The effects of oscillating electric forces on the spreading of droplets become negligible above a given threshold of the angular frequency of the oscillations. Non-dimensional analysis shows that this threshold depends on both the intensity of the electric force and the gas-phase properties, in particular the dynamic viscosity. The distribution of droplets in the channel is characterised by regions of preferential concentration, where fuel vapour mass fraction tends to be higher. Results also demonstrate that the time-averaged local fuel–air mixing is significantly affected by the period of oscillations, evaporation timescale and residence time in the channel. The present investigation further supports the proposal of using electric forces to improve fuel–air mixing in liquid-fuelled combustors, opening up new possibilities for fuel-preparation systems based on electrohydrodynamics.
Date Issued
2025-11-01
Date Acceptance
2025-05-20
Citation
International Journal of Multiphase Flow, 2025, 192
ISSN
0301-9322
Publisher
Elsevier
Journal / Book Title
International Journal of Multiphase Flow
Volume
192
Copyright Statement
© 2025 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
License URL
Publication Status
Published
Article Number
105289
Date Publish Online
2025-06-08