DOCSLIB.ORG

Investigation of Drop Generation from Low Velocity Liquid Jets and Its Impact Dynamics on Thin Liquid Films

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Investigation of Drop Generation from Low Velocity Liquid Jets and Its Impact Dynamics on Thin Liquid Films Investigation of Drop Generation from Low Velocity Liquid Jets and its Impact Dynamics on Thin Liquid Films A dissertation submitted to the Graduate School of the University of Cincinnati in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY (Ph.D.) in Mechanical Engineering of the College of Engineering and Applied Sciences by Sucharitha Rajendran September 2017 B.Tech., National Institute of Technology-Durgapur, 2010 M.S., University of Cincinnati, 2012 Committee Chair: Dr. Milind A. Jog Committee Member: Dr. Raj M. Manglik Committee Member: Dr. Kumar Vemaganti Committee Member: Dr. Woo Kyun Kim i ABSTRACT Drop generation from jet breakup and drop-impact on thin films are two key processes in many spray, coating and deposition applications which are experimentally and computationally investigated in this dissertation. A high-speed camera is used to capture the drop formation and its impingement on thin films and a modified volume of fluid (VOF) method is used to accurately simulate jet/film breakup. It is shown that the proposed modifications in interfacial property evaluations for VOF method provide accurate predictions of moving interface for highly viscous liquids. To understand the parameters governing uniform drop generation, a numerical study of the jet disintegration process, supplemented by experimental observations, is conducted. The simulations show that while an increase in viscous force offers greater resistance to propagation of the surface undulations thus resulting in stretching of the liquid jet, surface tension determines the radius of curvature of the pinch-off location. The interplay of these two forces leads to deviations from uniform drop generation and two different modes of liquid jet pinch-off that lead to satellite drop creation are observed. It is shown that the occurrence of these modes is governed by the liquid Morton number. A semi-empirical relation is proposed to predict the onset of the two modes. In most spray applications, the drops formed from a jet are incident on a target surface usually with a thin layer of liquid film. While viscous resistance to impact of the drop is offered by the film thus controlling drop spreading and crown formation, surface tension is noted to primarily govern the growth and eventual break-up of the ejected crown. An empirical relation for the onset of splash is obtained from high-speed image analyses of the drop-film interactions. Numerical simulation of the process indicates that the contribution of the target film and impacting drop in the creation of ejected crown depends on the film thickness. At low liquid film thickness, the liquid ii from the impacting drop primarily forms a jet that is ejected post-impact. For thicker films, the liquid layer absorbs a part of the energy from the impacting drop and thus the ejected jet is formed from both the impacting drop as well as the liquid layer. The temporal dynamics of deposition of Newtonian drops on thin films indicates that while surface tension and inertial forces govern resultant crown height, their contribution on crown diameter is not as significant. Viscosity is noted as the key factor that governs the crown diameter. In addition, experimental investigation of drop impact dynamics of shear thinning polymeric solution is carried out to understand the effects of solution rheology on the temporal dynamics. For aqueous solution of HEC 250 HHR, the apparent viscosity is low during initial impact (high shear rate) and this increases the likelihood of splashing compared to a Newtonian liquid with the same zero shear viscosity. High-speed images of drop impact on thin film of aqueous solution of PEO WSR 303 indicate that extensional viscosity also plays an important role in governing the post-impact behavior. iii iv ACKNOWLEDGMENTS I wish to express my most sincere gratitude and appreciation to those who have contributed to this work and to those who have been my support system throughout my academic journey. First, I am extremely grateful to my academic advisor, Dr. Milind A. Jog, and co-advisor Dr. Raj M. Manglik for their guidance and all the helpful brainstorming sessions. These discussions always helped me gain new insights into the problem and often I would come out looking at the problem in new light. Apart from this, I have often found myself being inspired by Dr. Jog and Dr. Manglik’s clarity in thinking – be it to resolve some tough numerical road blocks or to device better means of conceptual analysis. I would like to also thank my committee members, Dr. Kumar Vemaganti and Dr. Woo Kyun Kim for taking interest in my research and providing helpful suggestions and important insights. During my course of research, I have gotten to know some university staff members that I wish to express my gratitude to. Bo Westheider has helped me with setting up experiments and fixing multiple equipment for the different needs of the testing. Larry Schartman has helped me innumerable times to set-up and fix (and repeat) workstations for the different needs that arose. Luree Blythe and Barbara Carter have always been very approachable and helpful. I would also like to thank the very knowledgeable staff and consultants at OCC who helped with the many software and printing issues I’ve had over the years. Apart from working on my research, I was a part of the CEEMS (Cincinnati Engineering Enhanced Math and Science) fellowship and had the lovely opportunity to interact with students and teachers in their daily classroom lessons. I would like to thank Dr. Anant Kukreti, Julie Steimle, Debora Liberi and all the teachers for this experience. I have also been a part of the UC Simulation center and my interactions with Proctor and Gamble mentors and the projects I worked on have taught v me a lot. Working with both Dr. Joe Grolmes and Rakesh Gummalla has been a lovely learning experience. Dr. Brent Rudd and Fred Murrell’s enthusiasm to maintain the great working environment made it the experience marvelous. Apart from these two organizations, I would also like to thank the Education and Research Center’s (ERC) Pilot Research Program (PRP) for providing the initial funding for this project. The interest to pursue a PhD degree in Fluid and thermal science stems from Dr. Amarnath Mullick’s always cheerful motivation. I take this opportunity to thank him for encouraging me to pursue summer research fellowships during my under-graduation at NIT Durgapur, in addition to providing guidance to a very challenging and interesting senior year project. I appreciate the help and support provided by my colleagues at Thermal Fluid and Thermal Processing Laboratory. This was always a fun work environment. During my stay at Cincinnati, I have had the fortune of the company of some very good friends that have made this duration even more memorable: Deepak Saagar, An Fu, Wilma Lam, Sai Deogekar, Raghunandan Chilkuri, Srikirti Velaga, Amruta Dongonkar, Gautam Krothapalli, Santhosh Dungi, Suryanarayana Pappu, Anup Srikumar, Aditya Mantri, Sruti Jagabatulla, Vibhu Gautam, and many others. I would like to express my most sincere gratitude to Karthik Remella for not only being a pillar of support though everything, but also for being a constant source of inspiration and pushing me to always try harder. And finally, I am forever indebted to my parents, Rajendran and Jadila and to my brother Shashank, and to all my family for their unconditional love and support. Through times that have seemed discouraging and through those that were joyous, they have always shared an important part. They are my backbone. This work would not be a reality without them and I would like to dedicate this dissertation to them. vi TABLE OF CONTENTS Abstract ........................................................................................................................................... ii Acknowledgments........................................................................................................................... v Table of Contents .......................................................................................................................... vii Nomenclature .................................................................................................................................. x List of Figures ............................................................................................................................... xii List of Tables .............................................................................................................................. xvii 1 Chapter 1: Introduction ............................................................................................................ 1 1.1 Jet breakup and the resultant drop distribution ....................................................... 1 1.2 Drop impact dynamics ............................................................................................ 5 1.3 Scope of the current research .................................................................................. 9 2 Chapter 2: Modified Volume of Fluid method for two-phase flows ..................................... 12 1.4 Introduction ........................................................................................................... 12 1.5 Numerical Procedure ............................................................................................ 14 1.5.1 Governing Equations ................................................................................. 15
Load more

Recommended publications
  • RESOURCES in NUMERICAL ANALYSIS Kendall E
    RESOURCES IN NUMERICAL ANALYSIS Kendall E. Atkinson University of Iowa Introduction I. General Numerical Analysis A. Introductory Sources B. Advanced Introductory Texts with Broad Coverage C. Books With a Sampling of Introductory Topics D. Major Journals and Serial Publications 1. General Surveys 2. Leading journals with a general coverage in numerical analysis. 3. Other journals with a general coverage in numerical analysis. E. Other Printed Resources F. Online Resources II. Numerical Linear Algebra, Nonlinear Algebra, and Optimization A. Numerical Linear Algebra 1. General references 2. Eigenvalue problems 3. Iterative methods 4. Applications on parallel and vector computers 5. Over-determined linear systems. B. Numerical Solution of Nonlinear Systems 1. Single equations 2. Multivariate problems C. Optimization III. Approximation Theory A. Approximation of Functions 1. General references 2. Algorithms and software 3. Special topics 4. Multivariate approximation theory 5. Wavelets B. Interpolation Theory 1. Multivariable interpolation 2. Spline functions C. Numerical Integration and Differentiation 1. General references 2. Multivariate numerical integration IV. Solving Differential and Integral Equations A. Ordinary Differential Equations B. Partial Differential Equations C. Integral Equations V. Miscellaneous Important References VI. History of Numerical Analysis INTRODUCTION Numerical analysis is the area of mathematics and computer science that creates, analyzes, and implements algorithms for solving numerically the problems of continuous mathematics. Such problems originate generally from real-world applications of algebra, geometry, and calculus, and they involve variables that vary continuously; these problems occur throughout the natural sciences, social sciences, engineering, medicine, and business. During the second half of the twentieth century and continuing up to the present day, digital computers have grown in power and availability.
    [Show full text]
  • Efficient Space-Time Sampling with Pixel-Wise Coded Exposure For
    IEEE TRANSACTIONS ON PATTERN ANALYSIS AND MACHINE INTELLIGENCE 1 Efficient Space-Time Sampling with Pixel-wise Coded Exposure for High Speed Imaging Dengyu Liu, Jinwei Gu, Yasunobu Hitomi, Mohit Gupta, Tomoo Mitsunaga, Shree K. Nayar Abstract—Cameras face a fundamental tradeoff between spatial and temporal resolution. Digital still cameras can capture images with high spatial resolution, but most high-speed video cameras have relatively low spatial resolution. It is hard to overcome this tradeoff without incurring a significant increase in hardware costs. In this paper, we propose techniques for sampling, representing and reconstructing the space-time volume in order to overcome this tradeoff. Our approach has two important distinctions compared to previous works: (1) we achieve sparse representation of videos by learning an over-complete dictionary on video patches, and (2) we adhere to practical hardware constraints on sampling schemes imposed by architectures of current image sensors, which means that our sampling function can be implemented on CMOS image sensors with modified control units in the future. We evaluate components of our approach - sampling function and sparse representation by comparing them to several existing approaches. We also implement a prototype imaging system with pixel-wise coded exposure control using a Liquid Crystal on Silicon (LCoS) device. System characteristics such as field of view, Modulation Transfer Function (MTF) are evaluated for our imaging system. Both simulations and experiments on a wide range of
    [Show full text]
  • Applied Analysis & Scientific Computing Discrete Mathematics
    CENTER FOR NONLINEAR ANALYSIS The CNA provides an environment to enhance and coordinate research and training in applied analysis, including partial differential equations, calculus of Applied Analysis & variations, numerical analysis and scientific computation. It advances research and educational opportunities at the broad interface between mathematics and Scientific Computing physical sciences and engineering. The CNA fosters networks and collaborations within CMU and with US and international institutions. Discrete Mathematics & Operations Research RANKINGS DOCTOR OF PHILOSOPHY IN ALGORITHMS, COMBINATORICS, U.S. News & World Report AND OPTIMIZATION #16 | Applied Mathematics Carnegie Mellon University offers an interdisciplinary Ph.D program in Algorithms, Combinatorics, and #7 | Discrete Mathematics and Combinatorics Optimization. This program is the first of its kind in the United States. It is administered jointly #6 | Best Graduate Schools for Logic by the Tepper School of Business (Operations Research group), the Computer Science Department (Algorithms and Complexity group), and the Quantnet Department of Mathematical Sciences (Discrete Mathematics group). #4 | Best Financial Engineering Programs Carnegie Mellon University does not CONTACT discriminate in admission, employment, or Logic administration of its programs or activities on Department of Mathematical Sciences the basis of race, color, national origin, sex, handicap or disability, age, sexual orientation, 5000 Forbes Avenue gender identity, religion, creed, ancestry,
    [Show full text]
  • Metal Complexes of Penicillin and Cephalosporin Antibiotics
    I METAL COMPLEXES OF PENICILLIN AND CEPHALOSPORIN ANTIBIOTICS A thesis submitted to THE UNIVERSITY OF CAPE TOWN in fulfilment of the requirement$ forTown the degree of DOCTOR OF PHILOSOPHY Cape of by GRAHAM E. JACKSON University Department of Chernis try, University of Cape Town, Rondebosch, Cape, · South Africa. September 1975. The copyright of th:s the~is is held by the University of C::i~r:: To\vn. Reproduction of i .. c whole or any part \ . may be made for study purposes only, and \; not for publication. The copyright of this thesis vests in the author. No quotation from it or information derived from it is to be published without full acknowledgementTown of the source. The thesis is to be used for private study or non- commercial research purposes only. Cape Published by the University ofof Cape Town (UCT) in terms of the non-exclusive license granted to UCT by the author. University '· ii ACKNOWLEDGEMENTS I would like to express my sincere thanks to my supervisors: Dr. L.R. Nassimbeni, Dr. P.W. Linder and Dr. G.V. Fazakerley for their invaluable guidance and friendship throughout the course of this work. I would also like to thank my colleagues, Jill Russel, Melanie Wolf and Graham Mortimor for their many useful conrrnents. I am indebted to AE & CI for financial assistance during the course of. this study. iii ABSTRACT The interaction between metal"'.'ions and the penici l)in and cephalosporin antibiotics have been studied in an attempt to determine both the site and mechanism of this interaction. The solution conformation of the Cu(II) and Mn(II) complexes were determined using an n.m.r, line broadening, technique.
    [Show full text]
  • Quality Improvement of Compressed Color Images Using a Probabilistic Approach
    QUALITY IMPROVEMENT OF COMPRESSED COLOR IMAGES USING A PROBABILISTIC APPROACH Nobuteru Takao, Shun Haraguchi, Hideki Noda, Michiharu Niimi Kyushu Institute of Technology, Dept. of Systems Design and Informatics, 680-4 Kawazu, Iizuka, 820-8502 Japan E-mail: {takao, haraguchi, noda, niimi}@mip.ces.kyutech.ac.jp ABSTRACT method using information on luminance component which is not downsampled. In compressed color images, colors are usually represented by luminance and chrominance (YCbCr) components. Con- The interpolation aims to recover only resolution of chromi- sidering characteristics of human vision system, chromi- nance components lost by downsampling. Alternatively, we nance (CbCr) components are generally represented more aim to recover not only resolution lost by downsampling coarsely than luminance component. Aiming at possible re- but also precision lost by a coarser quantization, if possi- covery of chrominance components, we propose a model- ble. Aiming at such recovery of chrominance components, based chrominance estimation algorithm where color im- we propose a model-based method where color images are ages are modeled by a Markov random field (MRF). A sim- modeled by a Markov random field (MRF). A simple MRF ple MRF model is here used whose local conditional proba- model is here used whose local conditional probability den- bility density function (pdf) for a color vector of a pixel is a sity function (pdf) for a color vector of a pixel is a Gaussian Gaussian pdf depending on color vectors of its neighboring pdf depending on color vectors of its neighboring pixels. pixels. Chrominance components of a pixel are estimated Chrominance components of a pixel are estimated by max- by maximizing the conditional pdf given its luminance com- imizing the conditional pdf given its luminance component ponent and its neighboring color vectors.
    [Show full text]
  • Numerical Analysis to Quantum Computing
    Credit: evv/Shutterstock.com and D-Wave, Inc. and D-Wave, Credit: evv/Shutterstock.com How NASA-USRA collaborations have advanced knowledge in and with the use of new computing technologies. When USRA was created in 1969, later its first task was the management the Chief Scientist at the FROM of the Lunar Science Institute near Center. In February of 1972, Duberg NASA’s Manned Spacecraft Center wrote a memorandum to the senior NUMERICAL (now the Johnson Space Center). management of LaRC, expressing A little more than three years his view that: TO later, USRA began to manage the ANALYSIS Institute for Computer Applications The field of computers and their in Science and Engineering (ICASE) application in the scientific QUANTUM at NASA’s Langley Research Center community has had a profound (LaRC). The rationale for creating effect on the progress of ICASE was developed by Dr. John aerospace research as well as COMPUTING E. Duberg (1917-2002), who was technology in general for the the Associate Director at LaRC and past 15 years. With the advent of “super computers,” based on parallel and pipeline techniques, the potentials for research and problem solving in the future seem even more promising and challenging. The only question is how long will it take to identify the potentials, harness the power, and develop the disciplines necessary to employ such tools effectively.1 Twenty years later, Duberg reflected on the creation of ICASE: By the 1970s, Langley’s computing capabilities had kept pace with the rapidly developing John E. Duberg, Chief Scientist, LaRC; George M.
    [Show full text]
  • Mathematics (MATH) 1
    Mathematics (MATH) 1 MATHEMATICS (MATH) MATH 505: Mathematical Fluid Mechanics 3 Credits MATH 501: Real Analysis Kinematics, balance laws, constitutive equations; ideal fluids, viscous 3 Credits flows, boundary layers, lubrication; gas dynamics. Legesgue measure theory. Measurable sets and measurable functions. Prerequisite: MATH 402 or MATH 404 Legesgue integration, convergence theorems. Lp spaces. Decomposition MATH 506: Ergodic Theory and differentiation of measures. Convolutions. The Fourier transform. MATH 501 Real Analysis I (3) This course develops Lebesgue measure 3 Credits and integration theory. This is a centerpiece of modern analysis, providing a key tool in many areas of pure and applied mathematics. The course Measure-preserving transformations and flows, ergodic theorems, covers the following topics: Lebesgue measure theory, measurable sets ergodicity, mixing, weak mixing, spectral invariants, measurable and measurable functions, Lebesgue integration, convergence theorems, partitions, entropy, ornstein isomorphism theory. Lp spaces, decomposition and differentiation of measures, convolutions, the Fourier transform. Prerequisite: MATH 502 Prerequisite: MATH 404 MATH 507: Dynamical Systems I MATH 502: Complex Analysis 3 Credits 3 Credits Fundamental concepts; extensive survey of examples; equivalence and classification of dynamical systems, principal classes of asymptotic Complex numbers. Holomorphic functions. Cauchy's theorem. invariants, circle maps. Meromorphic functions. Laurent expansions, residue calculus. Conformal
    [Show full text]
  • Computational Methods for Numerical Analysis with R James P
    JSS Journal of Statistical Software November 2018, Volume 87, Book Review 2. doi: 10.18637/jss.v087.b02 Reviewer: Abdolvahab Khademi University of Massachusetts Computational Methods for Numerical Analysis with R James P. Howard, II Chapman & Hall/CRC, Boca Raton, 2017. ISBN 9781498723633. xx+257 pp. USD 99.95 (H). https://www.crcpress.com/9781498723633 Numerical approximation algorithms have traditionally been implemented in generic and specialized programming languages, such as C++, Fortran, and MATLAB. However, newer programming languages such as Python and R are becoming more popular among students and researchers. What makes the latter languages distinct from the traditional ones is their tuning towards data analysis (structurally and through libraries), their free cost and accessibility to everyone, and faster updates due to community-based development. These amenities are the main drivers behind the rise and adoption of such modern computational languages. Computational Methods for Numerical Analysis with R reflects this change and a future trend in the use of modern specialized programming languages, such as R. This book is structured in seven chapters, essentially covering the topics in an undergraduate course in numerical analysis. In each chapter, the author presents the concepts clearly, pro- vides R code for the different algorithms used for computations, presents insights, and ends the chapter with a good number of exercises for the reader. The exercises provide practice in both coding and conceptual understanding. The author’s website provides all the R code in a package and an errata sheet. Numerical analysis is defined and compared with symbolic computation in Chapter 1, In- troduction to Numerical Analysis.
    [Show full text]
  • Numerical Analysis and Computing Lecture Notes #01 — First Meeting
    The Professor The Class — Overview The Class... Introduction Application Numerical Analysis and Computing Lecture Notes #01 — First Meeting Joe Mahaffy, [email protected] Department of Mathematics Dynamical Systems Group Computational Sciences Research Center San Diego State University San Diego, CA 92182-7720 http://www-rohan.sdsu.edu/∼jmahaffy Spring 2010 Joe Mahaffy, [email protected] Lecture Notes #01 — First Meeting — (1/26) The Professor The Class — Overview The Class... Introduction Application Outline 1 The Professor Contact Information, Office Hours 2 The Class — Overview Literature & Syllabus Grading CSU Employee Furloughs Expectations and Procedures 3 The Class... Resources Formal Prerequisites 4 Introduction The What? Why? and How? 5 Application Analysis Joe Mahaffy, [email protected] Lecture Notes #01 — First Meeting — (2/26) The Professor The Class — Overview The Class... Contact Information, Office Hours Introduction Application Contact Information Office GMCS-593 Email mahaff[email protected] Web http://www-rohan.sdsu.edu/∼jmahaffy Phone (619)594-3743 Office Hours MW: 1 – 2, 3 – 4), and by appointment Joe Mahaffy, [email protected] Lecture Notes #01 — First Meeting — (3/26) The Professor Literature & Syllabus The Class — Overview Grading The Class... CSU Employee Furloughs Introduction Expectations and Procedures Application Basic Information: The Book Title: “Numerical Analysis,” 8th Edition Authors: Richard L. Burden & J. Douglas Faires Publisher: Thomson – Brooks/Cole ISBN: 0-534-39200-8 Joe Mahaffy, [email protected]
    [Show full text]
  • An Investigation of Droplets and Films Falling Over Horizontal Tubes
    Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1-1-2003 An investigation of droplets and films falling vo er horizontal tubes Jesse David Killion Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/rtd Recommended Citation Killion, Jesse David, "An investigation of droplets and films falling vo er horizontal tubes" (2003). Retrospective Theses and Dissertations. 19454. https://lib.dr.iastate.edu/rtd/19454 This Thesis is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. An investigation of droplets and films falling over horizontal tubes by Jesse David Killion A thesis submitted to the graduate faculty in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Major: Mechanical Engineering Program of Study Committee: Srinivas Garimella, Major Professor Richard H. Pletcher James C. Hill Iowa State University Ames, Iowa 2003 Copyright OO Jesse David Killion, 2003. All rights reserved. 11 Graduate College Iowa State University This is to certify that the master's thesis of Jesse David Killion has met the thesis requirements of Iowa State University Signatures have been redacted for privacy 111 TABLE OF CONTENTS ABSTRACT V ACKNOWLEDGEMENTS
    [Show full text]
  • Application of Graph Theory to the Nonlinear Analysis of Large Space Structures Magdy Ibrahim Hindawy Iowa State University
    Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1986 Application of graph theory to the nonlinear analysis of large space structures Magdy Ibrahim Hindawy Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Aerospace Engineering Commons Recommended Citation Hindawy, Magdy Ibrahim, "Application of graph theory to the nonlinear analysis of large space structures " (1986). Retrospective Theses and Dissertations. 8007. https://lib.dr.iastate.edu/rtd/8007 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. INFORMATION TO USERS This reproduction was made from a copy of a memuscript sent to us for publication and microfilming. While the most advanced technology has been used to pho­ tograph and reproduce this manuscript, the quality of the reproduction Is heavily dependent upon the quality of the material submitted. Pages In any manuscript may have Indistinct print. In all cases the best available copy has been filmed. The following explanation of techniques Is provided to help clarify notations which may appear on this reproduction. 1. Manuscripts may not always be complete. When it Is not possible to obtain missing pages, a note appears to indicate this. 2. When copyrighted materials are removed from the manuscript, a note ap­ pears to indicate this. 3. Oversize materials (maps, drawings, and charts) are photographed by sec­ tioning the original, beginning at the upper left hand comer and continu­ ing from left to right in equal sections with small overlaps.
    [Show full text]
  • Energy Technology and Management
    ENERGY TECHNOLOGY AND MANAGEMENT Edited by Tauseef Aized Energy Technology and Management Edited by Tauseef Aized Published by InTech Janeza Trdine 9, 51000 Rijeka, Croatia Copyright © 2011 InTech All chapters are Open Access articles distributed under the Creative Commons Non Commercial Share Alike Attribution 3.0 license, which permits to copy, distribute, transmit, and adapt the work in any medium, so long as the original work is properly cited. After this work has been published by InTech, authors have the right to republish it, in whole or part, in any publication of which they are the author, and to make other personal use of the work. Any republication, referencing or personal use of the work must explicitly identify the original source. Statements and opinions expressed in the chapters are these of the individual contributors and not necessarily those of the editors or publisher. No responsibility is accepted for the accuracy of information contained in the published articles. The publisher assumes no responsibility for any damage or injury to persons or property arising out of the use of any materials, instructions, methods or ideas contained in the book. Publishing Process Manager Iva Simcic Technical Editor Teodora Smiljanic Cover Designer Jan Hyrat Image Copyright Sideways Design, 2011. Used under license from Shutterstock.com First published September, 2011 Printed in Croatia A free online edition of this book is available at www.intechopen.com Additional hard copies can be obtained from [email protected] Energy Technology and Management, Edited by Tauseef Aized p. cm. ISBN 978-953-307-742-0 free online editions of InTech Books and Journals can be found at www.intechopen.com Contents Preface IX Part 1 Energy Technology 1 Chapter 1 Centralizing the Power Saving Mode for 802.11 Infrastructure Networks 3 Yi Xie, Xiapu Luo and Rocky K.
    [Show full text]