Atomization of Liquids in Non-isothermal Environments: Multi-scale Modeling and Simulations

Arizona State University, Scottsdale AZ

Investigators

Abstract

Atomization of liquids is a key component in many natural phenomena and technical processes. Yet, detailed understanding of the fundamental physical processes is incomplete, due to the inherent complexity of atomization and the inability to experimentally observe the processes in detail. This project focuses on improved understanding of the phenomenon by computational studies, on massively parallel computational facilities, of mathematical models that incorporate the interaction and competition among several forces acting on multiple length and time scales. High-fidelity gas/liquid interface tracking algorithms based on the level-set approach will be combined with efficient Lagrangian descriptions of small-scale liquid droplets. Thermal Marangoni effects due to the temperature dependence of surface tension will be included, along with evaporation and related effects of latent heat, with the intent to examine the extent to which these processes affect the fragmentation cascades of droplets in high-inertia flow. The project will enable breakthroughs in the understanding of physical mechanisms that govern the process of atomization, with potential impact on a broad range of applications. Foremost among these are energy systems, where the design of fuel-efficient and low-polluting engines hinges on the air/fuel mix for optimal combustion, and that in turn depends critically on the droplet size distribution from the atomization of the injected jet of fuel. This will aid in achieving national goals of energy independence and environment sustainability. Other applications include aerosol drug delivery, agricultural sprays, and fire-fighting (here atomization of the water jet is to be avoided for increased flame quenching). Accurate atomization models of waves producing sea spray and small air bubbles driven deep into the ocean by breaking waves, especially those associated with large-scale storms and hurricanes, can lead to improved weather and climate modeling and predictions of the impact of greenhouse gases on global warming. The project also includes the interdisciplinary training of graduate and undergraduate students.