Abstract
The Phase Doppler Particle Analyzer (PDPA) technique is utilized for characterizing the droplet sizes and velocity profiles in an electrostatic spray flow which is atomized using the aerodynamic forces assisted with electrostatic forces. An electrostatically-assisted twin-fluid atomization system is presented and spatial distributions of the droplet size and two-dimensional velocity components are measured simultaneously at each specified point. The droplets are firstly ejected from a liquid jet through the nozzle by aerodynamic shear forces, and the breakup mechanism of such an electrostatically-assisted twin-fluid atomization is investigated using the Rayleigh instability conditions through studying the specific surface charges on these droplets measured by a Faraday canister. The discrepancies between experiment data and Rayleigh limit for specific charges of droplets are presented and discussed due to energy transforming from electrical energy to surface energy, energy loss, Taylor instability breakup and nonexcess charge polarization. The measured average velocity profiles and their RMS (root mean square) velocity values for two different scale drops further reveal the effects of the aerodynamic and electrostatic forces on the atomization process.
Highlights
The twin-fluid atomization technology has been widely implemented in atomizing the highly viscous fluids such as the water-coal slurry, heavy oil, lime water, and pesticide liquids [1,2,3,4,5]
Phase Doppler Particle Analyzer (PDPA) measurements are utilized to characterize the spatial distributions of droplets size and velocity
Experimental data reveals that the droplets size is influenced by the external electrical field, while the droplet velocity is controlled by the aerodynamic force
Summary
The twin-fluid atomization technology has been widely implemented in atomizing the highly viscous fluids such as the water-coal slurry, heavy oil, lime water, and pesticide liquids [1,2,3,4,5]. Some significant progress has been made in developing the PDPA technique for characterizing the pure twin-fluid atomization, pure electrostatic atomization and sprays, useful experimental data, especially these twin-fluid atomization patterns associated with electrostatic forces and gas-droplets trajectories, are still scarce due to the inherent complexity and difficulty in in situ mapping of droplet sizes and the gas droplets two-phase velocity field In this present work, a twin-fluid aerodynamic atomization device is integrated with a combined annular-needle electrode which produces an electrostatic field. A twin-fluid aerodynamic atomization device is integrated with a combined annular-needle electrode which produces an electrostatic field The design of this system, through utilizing both the aerodynamic and electrostatic forces, allows for easier and effective controls of the ratio of gas to liquid flow rates and the droplets charging voltage. It is expected that the testing apparatus and experimental data would provide a platform for further investigating the characteristics of electrostatically assisted twin-fluid atomization for liquids and multiphase flows with different applications
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
