An authoritative review of the science and technology of droplets and sprays.

This book serves as both a graduate text and a reference for engineers and scientists exploring the theoretical and computational aspects of the fluid dynamics and transport of sprays and droplets. Attention is given to the behavior of individual droplets, including the effects of forced convection due to relative droplet-gas motion, Stefan convection due to the vaporization or condensation of the liquid, multicomponent liquids (and slurries), and internal circulation of the liquid. This second edition contains more information on droplet-droplet interactions, the use of the mass-flux potential, conserved scalar variables, spatial averaging and the formulation of the multi-continua equations, the confluence of spatial averaging for sprays and filtering for turbulence, direct numerical simulations and large-eddy simulations for turbulent sprays, and high-pressure vaporization processes. Two new chapters introduce liquid-film vaporization as an alternative to sprays for miniature applications and a review of liquid-stream distortion and break-up theory, which is relevant to spray formation.

This book discusses the theoretical foundations of spray and droplet applications relevant to the technology for active control of sprays applied to new products and applications, improved product performance, cost reductions, and improved environmental outcomes. It also covers theory related to power and propulsion; materials processing and manufacturing technologies including droplet-based net form processing, coating, and painting; medication; pesticides and insecticides; and other consumer uses.

The book deals with the dynamical behaviour of single droplets and regular droplet systems. It has been written mainly for experimental researchers. After a short description of the theoretical background, the different experimental facilities and methods necessary for the investigation of single droplets are described in detail. A summary of important applications is included.

This book provides a selection of contributions to the DIPSI workshop 2019 (Droplet Impact Phenomena & Spray Investigations) as well as recent progress of the Int. Research Training Group “DROPIT”.The DIPSI workshop, which is now at its thirteenth edition, represents an important opportunity to share recent knowledge on droplets and sprays in a variety of research fields and industrial applications. The research training group “DROPIT” is focused on droplet interaction technologies where microscopic effects influence strongly macroscopic behavior. This requires the inclusion of interface kinetics and/or a detailed analysis of surface microstructures. Normally, complicated technical processes cover the underlying basic mechanisms, and therefore, progress in the overall process modelling can hardly be gained. Therefore, DROPIT focuses on the underlying basic processes. This is done by investigating different spatial and/or temporal scales of the problems and by linking them through a multi-scale approach. In addition, multi-physics are required to understand e.g. problems for droplet-wall interactions, where porous structures are involved.

This is the first book to encompass the fundamental phenomenon, principles, and processes of discrete droplets of both normal liquids and melts. It provides the reader with the science and engineering of discrete droplets, and provides researchers, scientists and engineers with the latest developments in the field. The book begins with a systematic review of various processes and techniques, along with their applications and associations with materials systems. This is followed by a description of the phenomena and principles in droplet processes. Correlations, calculations, and numerical modeling of the droplet processes provide insight into the effects of process parameters on droplet properties for optimization of atomizer design. Droplets are found in the areas of metallurgy, materials, automotive, aerospace, medicine, food processing, agriculture, and power generation, and encountered in a huge range of engineering applications.

Scale modeling can play an important role in R&D. When engineers receive some ideas in new product development, they can test how the new design looks by bui- ing scale models and they can get an actual feeling with the prototype through their imagination. Professor Emori often said: “When children play with a toy airplane, their mind is wondering about the prototype airplane which they haven’t ridden. ” Children can use the scale model airplane as a means to enter into an imagi- tive world of wonder by testing in their own way how the actual airplane might function, how the actual airplane can maneuver aerodynamically, what might be the actual sound of a jet engine, how to safely land the actual airplane, and so on. This imagination that scale models can provide for children will help them later develop professional intuition. Physical scale models can never be entirely succe- fully replaced by computer screens where virtual models are displayed and fancy functions are demonstrated. Not only children but also adults can learn things by actually touching things only offered by physical models, helping all of us develop imagination and feeling eventually leading toward Kufu. Einstein’s famous “thought experiments [11],” which helped him to restructure modern physics may possibly and effectively be taught by letting researchers play with scale models!? References 1. I. Emori, K. Saito, and K. Sekimoto, Mokei Jikken no Riron to Ouyou (Scale Models in Engineering: Its Theory and Application), Gihodo, Tokyo, Third Edition, 2000.