Effervescent atomizer produced sprays were studied for application to rotary kiln incinerators. The sprays were characterized by their number averaged droplet velocity profiles, Sauter mean diameter (SMD) profiles, and size-velocity correlations. Spray mass flow rates ranged from 30 to 120 g/s. Air-liquid-ratios by mass (ALRs) were between 2% and 10%. Data were obtained at seven to ten radial p...

We present the results of experiments studying droplet coalescence in a dense layer of emulsion droplets using microfluidic circuits. The microfluidic structure allows direct observation of collisions and coalescence events between oil droplets dispersed in water. The coalescence rate of a flowing hexadecane-in-water emulsion was measured as a function of the droplet velocity and droplet concen...

A quantitative description of the dynamics of droplet motion has been a long-standing concern in electrowetting research. Although many static and dynamic models focusing on droplet motion induced by electrowetting-on-dielectric (EWOD) already exist, some dynamic features do not fit these models well, especially the dynamic saturation phenomenon. In this paper, a dynamic saturation model of dro...

A lattice Boltzmann method which can simulate droplet dynamics on partial wetting surface with large liquid-gas density ratio is proposed. The interaction between the fluid-fluid interface and the partial wetting wall is typically considered. Using the method, the dynamics of liquid drops on chemically heterogeneous surfaces are numerically simulated. The corresponding mechanisms including drop...

In many electrowetting on dielectric (EWOD) based microfluidics devices, droplet actuation speed is a crucial performance-controlling parameter. Our present study aims to characterize and study droplet speed in a typical EWOD device. First, a practical droplet speed measurement method has been methodically demonstrated and some related velocity terms have been introduced. Next, influence of ele...

In this Part II, a thorough investigation of the melting of the electrode; the droplet formation, detachment, transfer and impingement onto the workpiece, and the weld-pool formation and dynamics was conducted. The transient melt-flow velocity and temperature distributions in the droplet and in the weld pool were calculated. The resulting crater in the weld pool and the weld-pool oscillation du...

This study presents an experimental investigation of a single droplet with different impingement velocity impinge on the hydrophilic and superhydrophobic substrates under normal and icing temperature by using high-speed image and infrared image techniques. The aim is to better understand the unsteady heat transfer and transient icing process of the aircraft icing caused by the supercooled large...

Spray cooling is one of the most promising technologies in applications which require large heat removal capacity in very small areas. Previous experimental studies have suggested that one of the main mechanisms of heat removal in spray cooling is forced convection with strong mixing due to droplet impingement. These mechanisms have not been completely understood mainly due to the large number ...

Accurate spray characterization helps to better understand the pesticide spray application process. The goal of this research was to present the proof of principle of a droplet size and velocity measuring technique for different types of hydraulic spray nozzles using a high speed backlight image acquisition and analysis system. As only part of the drops of an agricultural spray can be in focus ...

In hybrid laser–MIG keyhole welding, anti-crack elements can be added into the weld pool through a filler metal in anticipation of compensating mass loss, preventing porosity formation and improving compositional and mechanical properties of the welds. Understanding the mixing and diffusion of the filler metal in the molten pool is vital to achieve these desired objectives. In this study, mathe...