The Study of an Electrified Air-assisted Liquid Atomizer PDF Download

Author: Matthew James Alan Rickard
Publisher:
ISBN:
Category : Atomizers
Languages : en
Pages : 148

View

Book Description

Author: Rodrigo Osuna Orozco
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

View

Book Description
Multiphysics control of atomization is a promising new area of research that could result in more robust and versatile atomizers, producing a desired range of droplets under a very broad range of operating conditions. This would enable their use in applications that require the atomization process to operate within tight bounds under the influence of a changing environment and external perturbations. This dissertation studies the physics behind two-fluid coaxial atomization and transport of droplets in a turbulent gas jet, combined with the physics of electrostatic forcing. The effects of electrostatic forcing in the primary atomization, the resulting droplet population and the transport in the turbulent spray are studied over a wide range of gas-to-liquid momentum ratios, gas swirl ratios and electric field strengths. Based on the fundamental understanding of this complex multiphysics problem, a practical implementation of real-time electrostatic feedback control, based on sensing of the spray liquid distribution, is also demonstrated. First, the role of the electric field geometry in the primary breakup of coaxial atomization is studied. Evidence is presented for strong electric stresses with an axial component opposing the flow direction that increase the growth rate and decrease the wavelength of the interfacial instabilities initiated by the shear at the gas-liquid interface. This also results in reduced liquid core lengths and smaller droplets. In contrast, a predominantly radial electric field was shown to have little effect on the metrics mentioned above. The electrostatically assisted coaxial atomizer system at the basis of this thesis consists of a canonical coaxial nozzle enclosed between two large metallic plates held at a high electric potential. Atomization of an electrolyte solution revealed a combination of aerodynamic and electrostatic breakup mechanisms. For momentum ratios much lower than the electric Euler number, electrostatic processes were observed to dominate breakup. At high momentum ratios, aerodynamic breakup dominated the large scale features of the spray in the near field, but the electrostatic stresses gave rise to small-scale features, indicative of electrostatic breakup of small ligaments. Interferometric measurements in the mid field revealed substantial decreases in the droplet sizes due to electrostatic forcing. Substantial radial transport that modified the mean diameter and concentration profiles of the spray was achieved for coaxial atomization at many swirl ratios. We observed preferential radial transport of small droplets, consistent with electric charge densities following a power law of the diameter given by the classical Rayleigh limit for charged drop stability. Finally, real time feedback control is demonstrated. Proper orthogonal decomposition was used to characterize optical scattering and attenuation signals identifying the liquid distribution in the spray.

Author: Alex Baoda Liu
Publisher:
ISBN:
Category :
Languages : en
Pages : 346

View

Book Description

Author: Arthur Lefebvre
Publisher: CRC Press
ISBN: 1482227851
Category : Nature
Languages : en
Pages : 434

View

Book Description
Atomization and Sprays examines the atomization of liquids and characteristics of sprays. It explains the physical processes of atomization as well as guidelines for designing atomizers. In addition, it demonstrates how the importance of the size and velocity of a particle contributes to improved spray characterization. Coverage includes general co

Author: Arthur H. Lefebvre
Publisher: CRC Press
ISBN: 1498736262
Category : Technology & Engineering
Languages : en
Pages : 284

View

Book Description
The second edition of this long-time bestseller provides a framework for designing and understanding sprays for a wide array of engineering applications. The text contains correlations and design tools that can be easily understood and used in relating the design of atomizers to the resulting spray behavior. Written to be accessible to readers with a modest technical background, the emphasis is on application rather than in-depth theory. Numerous examples are provided to serve as starting points for using the information in the book. Overall, this is a thoroughly updated edition that still retains the practical focus and readability of the original work by Arthur Lefebvre.

Author: Kirk-Othmer
Publisher: John Wiley & Sons
ISBN: 0470047488
Category : Science
Languages : en
Pages : 2762

View

Book Description
This is an easily-accessible two-volume encyclopedia summarizing all the articles in the main volumes Kirk-Othmer Encyclopedia of Chemical Technology, Fifth Edition organized alphabetically. Written by prominent scholars from industry, academia, and research institutions, the Encyclopedia presents a wide scope of articles on chemical substances, properties, manufacturing, and uses; on industrial processes, unit operations in chemical engineering; and on fundamentals and scientific subjects related to the field.

Author: Ju-shan Chin
Publisher:
ISBN:
Category : Air-fuel ratio
Languages : en
Pages : 0

View

Book Description
Based on the experiences previously obtained from the experimental study of plain jet atomization under cross flowing air stream and under supersonic air flow, the authors designed and studied a serious of internal mixing sonic flow air assist atomizers for heavy oil application. The contradiction between the requirements for fine spray (for high combustion completeness) and for long flame (for flame rigidity) often existing in industrial furnace has been solved. Good data were obtained which can be used for the design of such kind atomizers. By properly choosing the configuration and geometrical dimensions of the atomizer, also by choosing suitable values for mixing chamber pressure, air-liquid ratio, it is possible to have very fine spray and desirable flame length. The results showed that the ratio of mixing chamber pressure to air supply pressure should be in the range of 0.6 to 0.7. For atmospheric pressure combustion furnace, such air assist atomizer needs 0.4 MPa compressed air to have sonic flow at nozzle exit. This type of air assist atomizer has already been put into industrial operation.

Author: L.P. Bayvel
Publisher: CRC Press
ISBN: 9780891169598
Category : Science
Languages : en
Pages : 488

View

Book Description
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 measure the macro- and microstructure parameters of atomized liquid. With a copious amount of numerical problems available for use as student tutorials, the book is suitable as a supplemental text for courses in mechanical, chemical, fuel, aeronautical, civil, and agricultural engineering.

Author: Xiaolan Lv
Publisher: Frontiers Media SA
ISBN: 2832549926
Category : Science
Languages : en
Pages : 236

View

Book Description
Plant chemical protection uses professional spraying machines to transport chemicals such as pesticides and herbicides to the target sites for pest, disease, and weed control in crop production. Such practices play a vital role in ensuring the supply of food, fruits, and vegetables for human beings. However, traditional plant chemical application methods suffer from excessive pesticide use, low utilization rate, and high labor intensity due to the backwardness of the existing sprayers, the single atomization technology, etc. In order to boost the progress of modern agriculture, plant chemical protection should be oriented toward efficient, accurate, and intelligent application technologies and equipment. Smart chemical application technology and efficient equipment can effectively reduce pesticide usage, mitigate the harm of chemicals to the environment, and lower labor intensity, realizing the sustainable development of disease and pest control of horticultural crops, ensuring food safety, and maintaining crop yield and quality.

Author: Saptarshi Basu
Publisher: Springer
ISBN: 9811074496
Category : Technology & Engineering
Languages : en
Pages : 433

View

Book Description
This book focuses on droplets and sprays relevant to combustion and propulsion applications. The book includes fundamental studies on the heating, evaporation and combustion of individual droplets and basic mechanisms of spray formation. The contents also extend to the latest analytical, numerical and experimental techniques for investigating the behavior of sprays in devices like combustion engines and gas turbines. In addition, the book explores several emerging areas like interactions between sprays and flames and the dynamic characteristics of spray combustion systems on the fundamental side, as well as the development of novel fuel injectors for specific devices on the application side. Given its breadth of coverage, the book will benefit researchers and professionals alike.