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Droplet Spreading (droplet + spreading)
Selected AbstractsMicrostructured Surfaces for Directional WettingADVANCED MATERIALS, Issue 47 2009Ville Jokinen Directional wetting on limited sectors of surfaces is achieved on partially wetting microstructured surfaces by placing nonsymmetrical microstructures in a regular rectangular lattice. Droplet spreading to a 90° sector is possible when the microstructures are designed to present broad features towards the right and top and sharp features towards the left and bottom (see image). [source] An experimental investigation on spreading of droplets with evaporation and nucleationHEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 1 2009Gui Lu Abstract An experimental investigation was conducted to visually observe the dynamic characteristics of water droplets with evaporation and nucleation on stainless steel and polished silicon surfaces. The water droplet diameter, contact area, and spreading speed were measured using a high-speed CCD camera at surface temperatures ranging from 110°C to 190°C, and a model was proposed to describe the dynamic behavior of droplet spreading. The spreading of water droplets under evaporation and nucleate boiling is highly dependent on the dynamic bubble behavior in the droplets, particularly bubble volume, bubble interaction, as well as the surface properties and temperature. Water droplets were easiest to spread at the surface temperature of 130 °C, and the spreading tendency increased with increasing surface coarseness. © 2008 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20231 [source] Efficient and accurate time adaptive multigrid simulations of droplet spreadingINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 11 2004P. H. Gaskell Abstract An efficient full approximation storage (FAS) Multigrid algorithm is used to solve a range of droplet spreading flows modelled as a coupled set of non-linear lubrication equations. The algorithm is fully implicit and has embedded within it an adaptive time-stepping scheme that enables the same to be optimized in a controlled manner subject to a specific error tolerance. The method is first validated against a range of analytical and existing numerical predictions commensurate with droplet spreading and then used to simulate a series of new, three-dimensional flows consisting of droplet motion on substrates containing topographic and wetting heterogeneities. The latter are of particular interest and reveal how droplets can be made to spread preferentially on substrates owing to an interplay between different topographic and surface wetting characteristics. Copyright © 2004 John Wiley & Sons, Ltd. [source] Direct Ink-Jet Printing of Vertical WallsJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 8 2002Xinglong Zhao Direct jet printing can assemble ceramic powder into a three dimensional shape by firing droplets of ink through a nozzle to build a multiple layered structure. As with stereolithography and selective laser sintering, the surface texture is expected to witness the layered assembly. The ability to create vertical walls by direct ink-jet printing was explored using a test piece based on a maze. The structure and topography are discussed in terms of droplet spreading and drying. [source] Recent advances in computational fluid dynamics relevant to the modelling of pesticide flow on leaf surfacesPEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 1 2010C Richard Glass Abstract Increasing societal and governmental concern about the worldwide use of chemical pesticides is now providing strong drivers towards maximising the efficiency of pesticide utilisation and the development of alternative control techniques. There is growing recognition that the ultimate goal of achieving efficient and sustainable pesticide usage will require greater understanding of the fluid mechanical mechanisms governing the delivery to, and spreading of, pesticide droplets on target surfaces such as leaves. This has led to increasing use of computational fluid dynamics (CFD) as an important component of efficient process design with regard to pesticide delivery to the leaf surface. This perspective highlights recent advances in CFD methods for droplet spreading and film flows, which have the potential to provide accurate, predictive models for pesticide flow on leaf surfaces, and which can take account of each of the key influences of surface topography and chemistry, initial spray deposition conditions, evaporation and multiple droplet spreading interactions. The mathematical framework of these CFD methods is described briefly, and a series of new flow simulation results relevant to pesticide flows over foliage is provided. The potential benefits of employing CFD for practical process design are also discussed briefly. © Crown copyright 2009. Reproduced with permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd. [source] | |||||||||||||