Download or read book Computational Study of Atomization in High Speed Gas Flow written by Steven Luong and published by . This book was released on 1992 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental and Computational Study on Liquid Atomization by Slinger Injector written by Carmen Sescu and published by . This book was released on 2011 with total page 219 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this research work the flow characteristics of a type of rotary atomizer, referred to as slinger injector, were experimentally and numerically investigated at relatively low rotational speeds. Although slinger injectors provide a good level of atomization at high rotational speeds where they are intended to operate (30,000 rpm or higher), a critical aspect in small gas turbines is related to the start-up phase, which typically takes place at speeds around 10,000 rpm. The quality of atomization is very important, especially at these low speeds where smaller mean fuel droplet diameters are desirable. The current work focused on the study of atomization provided by slinger injectors at rotational speed related pertinent to the start-up phase (up to 15,000 rpm). An optical measurement system was implemented to investigate the liquid atomization provided by the slinger injector. The qualitative behavior of fuel emerging from the slinger was evaluated to determine whether a satisfactory atomization was provided within a distance compatible with the size of a small gas turbine engine combustion chamber. The size of the droplets was measured using the Global Sizing Velocimetry (GSV) system. Visualization of the primary liquid breakup process, determination of breakup lengths, and measurement of droplet size were performed by varying rotational speed, liquid flow rate, injector hole shape, size and orientation, and number of holes. Photographs of the liquid breakup, various mean and representative diameters, droplet size histograms and cumulative volume distribution are presented. The findings of this thesis show that droplet size decrease with an increase in rotational speed, as expected. Moreover, hole diameter, hole shape and flow rates affect the slinger atomization. For a given flow rate and a given rotational speed, the experimental data show that the droplet sizes decrease by increasing the hole diameter. The droplets increase in size when the flow rates is increased for a given hole size. The atomization was found to be characteristically different for a slit compared to a circular hole injector. However, the orientation of the emerging jet relative to the axis of rotation insignificantly influenced the slinger atomization for the cases studied. A correlation equation was obtained for a slinger with circular hole, estimating the Sauter mean diameter as a function of the rotational speed of the slinger, the hole diameter, the liquid flow rate and the liquid properties. Two-dimensional and three-dimensional numerical simulations of the internal flow and the external near-field flow for a slinger atomizer were conducted. The simulations were carried out using the commercial Computational Fluid Dynamics code FLUENT, wherein the Volume of Fluid model was used to track the interface between the two phases. A User Defined Function was developed to take into account the centrifugal and Coriolis forces needed for FLUENT computations. The numerical simulations focused on the study of formation of the liquid film along the channel injector wall, and on the upstream characteristics of the liquid jet near the exit of the atomizer. The numerical simulations were in qualitative agreement with the experiment, showing that an annular jet exiting from the channel collapses and the liquid breaks up into droplets a short distance from the exist. The results show that the Volume of Fluid model is appropriate for developing simulation models of the working of a slinger atomizer.
Download or read book Computational Study of High Pressure Fuel Injection and Flow Passage Design for a Large bore Gas Engine written by Snehaunshu Chowdhury and published by . This book was released on 2004 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Masters Theses in the Pure and Applied Sciences written by Wade H. Shafer and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 426 pages. Available in PDF, EPUB and Kindle. Book excerpt: Masters Theses in the Pure and Applied Sciences was first conceived, published, and disseminated by the Center for Information and Numerical Data Analysis and Synthesis (CINDAS)* at Purdue University in 1957, starting its coverage of theses with the academic year 1955. Beginning with Volume 13, the printing and dis semination phases of the activity were transferred to University Microfilms/Xerox of Ann Arbor, Michigan, with the thought that such an arrangement would be more beneficial to the academic and general scientific and technical community. After five years of this joint undertaking we had concluded that it was in the interest of all concerned if the printing and distribution of the volumes were handled by an international publishing house to assure improved service and broader dissemination. Hence, starting with Volume 18, Masters Theses in the Pure and Applied Sciences has been disseminated on a worldwide basis by Plenum Publishing Corporation of New York, and in the same year the coverage was broadened to include Canadian universities. All back issues can also be ordered from Plenum. We have reported in Volume 38 (thesis year 1993) a total of 13,787 thesis titles from 22 Canadian and 164 United States universities. We are sure that this broader base for these titles reported will greatly enhance the value of this impor tant annual reference work. While Volume 38 reports theses submitted in 1993, on occasion, certain uni versities do report theses submitted in previous years but not reported at the time.
Download or read book Proceedings of the Heat Transfer and Fluid Mechanics Institute written by Heat Transfer and Fluid Mechanics Institute and published by . This book was released on 1993 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book CFD Modeling and Simulation in Materials Processing 2018 written by Laurentiu Nastac and published by Springer. This book was released on 2018-01-10 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: This collection presents contributions on computational fluid dynamics (CFD) modeling and simulation of engineering processes from researchers and engineers involved in the modeling of multiscale and multiphase phenomena in material processing systems. The following processes are covered: Additive Manufacturing (Selective Laser Melting and Laser Powder Bed Fusion); Ironmaking and Steelmaking (Ladle Metallurgical Furnace, EAF, Continuous Casting, Blown Converter, Reheating Furnace, Rotary Hearth Furnace); Degassing; High Pressure Gas Atomization of Liquid Metals; Electroslag Remelting; Electrokinetic Deposition; Friction Stir Welding; Quenching; High Pressure Die Casting; Core Injection Molding; Evaporation of Metals; Investment Casting; Electromagnetic Levitation; Ingot Casting; Casting and Solidification with External Field (electromagnetic stirring and ultrasonic cavitation) Interaction and Microstructure Evolution The collection also covers applications of CFD to engineering processes, and demonstrates how CFD can help scientists and engineers to better understand the fundamentals of engineering processes.
Download or read book Computational Aspects of Simple High speed Reacting Gas Flow written by James L. Throne and published by . This book was released on 1964 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Computational Simulation of Flow Inside Pressure swirl Atomizers written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Simplex atomizers (pressure-swirl atomizers) are widely used in air-breathing gas turbine engines as they have good atomization characteristics and are relatively simple and inexpensive to manufacture. To reduce emissions, it is critical to design fuel atomizers that can produce spray with a predetermined droplet size distribution at the desired combustor location (small mean droplet diameters and uniform local air/fuel ratios). Manufacturing methods are now available where complex atomizer geometries can be easily obtained. However to use such methods, the influence of atomizer geometry on its performance must be well understood. In this dissertation, a two-dimensional axisymmetric computational fluid dynamics (CFD) model based on the Arbitrary-Lagrangian-Eulerian (ALE) method to predict the flow in pressure-swirl atomizers was developed. The Arbitrary-Lagrangian-Eulerian method was applied so that the free interface between gas and liquid could be tracked sharply and accurately. The developed code was validated by comparison of predictions with experimental data for large scale prototype and with semi-empirical correlations at small scale. The computational predictions agreed well with experimental data for the film thickness at the exit, spray cone angle, and the pressure drop across the atomizer as well as velocity field in the swirl chamber. Using the validated code, a comprehensive parametric study on simplex atomizer performance was conducted. The geometric parameters of atomizer covered in this study include: atomizer constant, the ratio of length to diameter in swirl chamber, the ratio of length to diameter in orifice, the swirl chamber to orifice diameter ratio, inlet slot angle, trumpet angle, trumpet length, and swirl chamber convergent angle. The effects of these geometric parameters on the atomizer performance were studied for a fixed mass flow rate through the atomizer as well as for a fixed pressure drop across the atomizer. The atomizer performance was described in term of dimensionless film thickness at the exit, discharge coefficient and spray cone half angle. To address applications in pharmaceutical and food processing industry, flow of non-Newtonian power-law fluids through pressure-swirl atomizers was considered. Detailed flow patterns inside the atomizer for shear-thinning, Newtonian and shear-thickening fluids were investigated. A range of power-law index from 0.7 to 1.3 was considered. With a fixed flow rate through the atomizer, the shear-thickening fluids exhibited higher film thickness at exit, lower spray angle, and higher discharge coefficient compared to Newtonian fluids. For the range of power-law index considered in this study, the atomizer performance parameters for shear-thinning fluids showed small change from Newtonian fluids. The variation of atomizer performance with the atomizer constant was delineated for different power-law index.
Download or read book Computational Aspects of Simple Highspeed Reacting Gas Flow written by James Louis Throne and published by . This book was released on 1964 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Liquid Atomization written by L.P. Bayvel and published by Routledge. This book was released on 2019-01-22 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt: Covering the basics of liquid atomization, this book familiarizes readers with the physical processes of liquid atomization, the main types of atomizers and their design, measurements of spray characteristics, experimental investigations of atomizers, and application of atomizers. It demonstrates how to calculate and design atomizers and how to mea
Download or read book High speed Imaging and Computational Modelling of Close coupled Gas Atomization written by Shahed Motaman and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fluid Mechanics and Fluid Power Vol 2 written by Suvanjan Bhattacharyya and published by Springer Nature. This book was released on 2023-05-20 with total page 541 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the select proceedings of the 48th National Conference on Fluid Mechanics and Fluid Power (FMFP 2021) held at BITS Pilani in December 2021. It covers the topics such as fluid mechanics, measurement techniques in fluid flows, computational fluid dynamics, instability, transition and turbulence, fluid‐structure interaction, multiphase flows, micro- and nanoscale transport, bio-fluid mechanics, aerodynamics, turbomachinery, propulsion and power. The book will be useful for researchers and professionals interested in the broad field of mechanics.
Download or read book Computational Study of the Influence of Spray Atomization on Combustion in a Swirl Combustor written by J. Amaya and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Theoretical and experimental study on atomization of liquid drop in high speed gas stream written by Naotsugu Isshiki and published by . This book was released on 1959 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book DNS of Multiphase Flows Study of Atomization and Free surface Phenomena written by Eugenio Schillaci and published by . This book was released on 2018 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present thesis focuses on the numerical analysis of some diverse physical set-up that involve the interaction of two -or three immiscible and incompressible phases. The simulations are carried out by means of finite-volume algorithms developed on the in-house Computational Fluid Dynamics platform TermoFluids, developed by the Heat and Mass Transfer Technological Center (CTTC). They are intended to give detailed insights on the physics of the analyzed phenomena by carrying out Direct Numerical Simulations (DNS). In the context of multiphase flows, namely, Computational Multi-Fluid Dynamics (CMFD) field, DNS means that all the interfacial and turbulent scales of the phenomenon must be fully resolved. In the Introduction, a general overview of the engineering applications and the computational methods related to multiphase flows is proposed. The various types of physics analyzed in this work and the numerical approaches applied here to carry out efficient simulations are introduced. In Chapter 2, a low-dissipation convection scheme for the stable discretization of multiphase flow by means of interface-capturing schemes is analyzed. The hybrid form of the convective operator proposed incorporates localized low-dispersion characteristics to limit the growth of spurious flow solutions. Moreover, in comparison to pure-dissipative schemes, the discretization aims at minimizing the differences in kinetic energy preservation with respect to the continuous governing equations. This property plays a fundamental role in the case of flows presenting significant levels of turbulence. The simulation of a turbulent 2D coaxial jet with the low-dissipation convection scheme demonstrates its capability of solving correctly the two-phase turbulent problems. In Chapter 3, all the work carried out on the simulation of two-phase flow with the aid of Adaptive Mesh Refinement (AMR) strategies is described. The model is globally addressed at improving the representation of interfacial and turbulent scales in general multiphase flows. It is first applied to the simulation of simple multiphase phenomena, as 2D and 3D rising bubbles, to demonstrate the convergence of the method and the important computational savings in comparison to static mesh computations. However, its adoption becames essential in the simulation of instability and break-up phenomena, where the necessity of representing accurately the complex structures that appear at the interface, as ligaments and droplets, make the simulation particularly expensive in terms of computational cost. In Chapter 4, we analyze in detail the simulations of 3-D atomizing phenomena, including the coaxial jet case, characterized by the parallel injection of high speed liquid and gas fluxes, and the liquid spray case, characterized by the injection of a high speed liquid inside a still air chamber. In Chapter 5, an original single-phase scheme for the DNS of free-surface problems on 3-D unstructured meshes is presented. The scheme is based on a novel treatment of the interface for the deactivation of the light-phase, allowing an optimization of the classic two-phase model for the cases in which the influence of the lighter phase is negligible. Consequently, the model is particularly addressed at analyzing problems involving the movement of free-surfaces, as the evolution of waves on the sea, and their interaction with fixed and moving obstacles. Some practical cases of application are proposed, as the evaluation of stresses on an object due to the action of a dam-break event, and the interaction of linear waves with an oscillating water column device. In the same Chapter we describe the procedure to couple the single-phase model to the Immersed Boundary Method. The method is aimed at representing the interaction of a solid moving with prescribed velocity and the two-phase flow. The most significant example consists in the simulation of a sliding wedge into a liquid basin.
Download or read book Atomization and Sprays written by and published by . This book was released on 2008 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:
