Author: J. QianPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
An Experimental and Computational Study of Bouncing and Deformation in Droplet Collision
Author: J. QianA Computational Study Of Non-Newtonian Droplet Dynamics
Author: Kyle G. MooneyPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Sprays are encountered regularly in many industrial and military applications including inkjets, cooling processes, evaporation processes, catalyzation, coatings, and propulsion chambers. Spray atomization phenomena of Newtonian fluids have received significant academic and industrial research attention, however, the effect of non-Newtonian rheologies on spray formation and downstream droplet behavior has not been as heavily investigated. The aim of this work is to elucidate the effect of non-Newtonian and viscoelastic rheological effects on droplet behavior in the context of secondary atomization and droplet collisions. This study utilizes finite volume computational fluid dynamics (CFD) to recreate droplet fluid physics in a numerical setting to a high accuracy. Droplet collision systems comprised of Newtonian, viscoelastic and shear-thinning rheologies are simulated using a Lagrangian moving-mesh interface tracking method (MMIT). This interface tracking approach provides increased surface curvature accuracy on relatively coarse meshes compared to many Eulerian multiphase methods. Modeling assumptions and interface mesh treatments are validated using existing analytical and experimental comparisons showing good agreement. Interpolation error due to cell deformation is minimized with local topological mesh adaptation and a global element quality optimization algorithm. The fully three dimensional computational study investigates the effect of these non-Newtonian and viscoelastic rheologies on a droplet collision. Here, simulated fluid ligaments exhibit increased stability with greater relative elasticity. By applying the similar simulation techniques to collisions of shear thinning droplets, a simple reduced order viscosity model has been produced, valid within a certain range of Weber number values. Another important atomization phenomenon, secondary breakup, is simulated using a volume of fluids (VOF) based interface capturing method applied to a centroid tracking moving mesh. Here, an axisymmetric CFD study of the wind induced break up of both Newtonian and non-Newtonian droplets is presented with comparisons with experimentally observed results. The numerical implementation is further verified by displaying accurate recreation of rapid micro-scale bubble collapse processes and subsequent jet ejection observed in controlled laboratory settings. The presented simulation results show capability in prediction of both the transient deformation morphology and the time scales in which droplet disintegration occurs.
International Aerospace Abstracts
Author: Experimental and Computational Study of Droplet and Bubble Formation
Author: Bahman AbbasiPublisher:
ISBN:
Category : Bubbles
Languages : en
Pages : 218
Book Description
Numerical Simulations of Complex Multiphase Flows
Author: Judy Hweina CheARO and AFOSR Contractors Meeting in Chemical Propulsion, Held in Virginia Beach, Virginia on 3-6 June 1996
Author: David M. MannPublisher:
ISBN:
Category : Chemical reactions
Languages : en
Pages : 302
Book Description
Partial contents: Supercritical droplet behavior; Fundamentals of acoustic instabilities in liquid-propellant rockets; Modeling liquid jet atomization proceses; Liquid-propellant droplets dynamics and combustions in supercritical forced convective environments; Contributions of shear coaxial injectors to liquid rocket motor combustion instabilities; High pressure combustion studies under combustion driven oscillatory flow conditions; Droplet collision on liquid propellant combustion; Combustion and plumes; Development of a collisional radiative emission model for strongly nonequilibrium flows; Energy transfer processes in the production of excited states in reacting rocket flows; modeling nonequilibrium radiation in high altitude plumes; kinetics of plume radiation, and of HEDMs and metallic fuels combustion; Nonsteady combustion mechanisms of advanced solid propellants; Chemical mechanisms at the burning surface. p15
Droplet Dynamics on Chemically Striped Patterned Surfaces
Author: Hendrik Patrick JansenPublisher:
ISBN: 9789036537094
Category :
Languages : en
Pages : 175
Book Description
Experimental and Computational Study of Droplet Growth and Detachment Near the Inception Point
Author: Majid MolkiComputational Science – ICCS 2023
Author: Jiří MikyškaPublisher: Springer Nature
ISBN: 3031360303
Category : Computers
Languages : en
Pages : 809
Book Description
The five-volume set LNCS 14073-14077 constitutes the proceedings of the 23rd International Conference on Computational Science, ICCS 2023, held in Prague, Czech Republic, during July 3-5, 2023. The total of 188 full papers and 94 short papers presented in this book set were carefully reviewed and selected from 530 submissions. 54 full and 37 short papers were accepted to the main track; 134 full and 57 short papers were accepted to the workshops/thematic tracks. The theme for 2023, "Computation at the Cutting Edge of Science", highlights the role of Computational Science in assisting multidisciplinary research. This conference was a unique event focusing on recent developments in scalable scientific algorithms, advanced software tools; computational grids; advanced numerical methods; and novel application areas. These innovative novel models, algorithms, and tools drive new science through efficient application in physical systems, computational and systems biology, environmental systems, finance, and others.
Problems in Rarefied Flows and Chemical Kinetics
Author: Peng ZhangPublisher:
ISBN:
Category : Chemical kinetics
Languages : en
Pages : 245
Book Description
In Part II, a theoretical analysis was performed for the head-on collision of two identical droplets in a gaseous environment, with the attendant bouncing and coalescence outcomes, for situations in which the extent of droplet deformation upon collision is comparable to the original droplet radius, corresponding to O(1 − 10) of the droplet Weber number. The model embodies the essential physics that describes the substantial amount of droplet deformation, the viscous loss through droplet internal motion induced by the deformation, the dynamics and rarefied nature of the gas film between the interfaces of the colliding droplets, and the potential destruction and thereby merging of these interfaces due to the van der Waals attraction force. The theoretical model was applied to investigate collisions involving hydrocarbon and water droplets at sub- and super-atmospheric pressures. The results agree well with previous experimental observations in that as the Weber number increases in the range of O(1−10), collision of hydrocarbon droplets at one atmospheric pressure results in the nonmonotonic coalescence-bouncing-coalescence transition, that while bouncing is absent for water droplets at atmospheric pressure, it occurs at higher pressures, and that while bouncing is observed for hydrocarbon droplets at atmospheric pressure, it is absent at lower pressures.