The freezing of freely suspended supercooled water droplets with a diameter of bigger than a few micrometers splits into two rather different freezing stages. Within the first very fast dendritic freezing stage a spongy network ice with an ice portion of less than one-third forms and more than two-thirds of liquid water remain. In the present work the distribution of the ice portion in the drop...

This work aims to study the characteristics of multi-nozzle spray cooling using CFD method based on the fundamentals of air flow and liquid droplet collision dynamics. A mathematical model for the two-phase flow was presented. The simulations were performed using a EulerianeLagrangian approach. Focus was placed on revealing the flow behavior with multiple nozzles, the droplet trajectory, and th...

The extinction of an envelope flame at the forward stagnation point of a liquid fuel droplet due to forced convection is numerically investigated. The droplet is oxidizing within an air stream at atmospheric pressure. Combustion is modeled using finite-rate chemical kinetics and a one-step overall reaction. The gas-phase solution is obtained using the quasi-steady equations of mass, momentum, s...

The present article aims at developing simple realistic models in order to describe the gaseous removal process of SO(2) by absorption with and without chemical reaction in spray towers. Effects of droplet size, droplet velocity, superficial gas velocity, liquid flow rate and tower height on the performance of such a system are theoretically predicted. Model calculations bring out some very int...

In this research, the volume of fluid (VOF) method is used to study hydrodynamics rotating packed beds (RPBs). The model validated, and grid independence analyses are performed for cases with different operating conditions. droplet size distribution investigated characterize RPBs. Droplet distributions compared in two-dimensional three-dimensional simulations, it demonstrated that simulations c...

Transmission of respiratory infectious diseases in humans, for instance influenza, occurs by several modes. Respiratory droplets provide a vector of transmission of an infectious pathogen that may contribute to different transmission modes. An epidemiological model incorporating the dynamics of inhalable respiratory droplets is developed to assess their relevance in the infectious process. Inha...

Cryogenic sprays are of interest in dermatology for cooling human skin during pulsed laser treatment of port wine stain (PWS) birthmarks. In the present study, a Phase Doppler Interferometer (PDI) was used to obtain preliminary measurements of mean diameters and mean velocities of tetrafluoroethane (HFC-134a) spray droplets, generated by an atomizing nozzle of a commercial dermatological instru...

Droplet-based microfluidics has led to transformational new approaches in diverse areas including materials synthesis and high-throughput biological assays. However, the translation of droplet microfluidics technology into commercial applications requires scale-up of droplet generation from the laboratory (<10 mL h(-1)) to the industrial (>1 L h(-1)) scale. To address this challenge, we develop...

Microfluidic droplet formation at a T-junction in the jetting regime was studied theoretically and an analytical force balance model was proposed to predict the diameter of droplets. The forces governing droplet production in the jetting regime include the shear, interfacial tension, linear momentum and inertial forces. Experiments were carried with non-Newtonian xanthan gum solutions as the di...

The droplet separation from a liquid jet was investigated experimentally. Details of the shape of the thin liquid neck joining the droplet to its parent body were studied in terms of the fluid viscosity and the jet diameter. As the viscosity increased, the neck rapidly elongated creating a long thread. Its final diameter before rupture was approximately one micrometer and seems to be constant w...