Atomization characteristics of nano-Al/ethanol nanofluid fuel in electrostatic field

Abstract Electrostatic atomization has been widely applied in engineering, but few investigations on electrostatic atomization of liquid containing nanoparticles were carried out. This paper first presents the electrostatic atomization characteristics of nano-Al/ethanol nanofluid fuel and evaluates the contribution of nanoparticles to atomization characteristics. The physical properties of nano-Al/ethanol nanofluid were measured, suggesting that the density, surface tension and viscosity increase with enhancing the nano-Al concentration. The effects of the applied electric field voltage U, volume flow Q and nozzle size on electrostatic breakup of nanofluid jet and droplet formation were investigated in detail. It concludes that the average droplet diameter d follows a Q 1/2 law. The average diameter decreases significantly with the enhancement of the electric field voltage ranging with 17–25 kV. The decrease of nozzle size results in a reduction in average diameter of atomized droplets at critical breakup voltage. The nanofluid fuel of higher concentration exerted by the electrical field has a better atomization performance. When the nano-Al concentration reached 5.0 mg/ml, the atomized droplets became ultrafine and uniformly distributive. In comparison to 0.5 mg/ml, the average diameter can be reduced to one tenth (∼9 μm).