Download or read book Direct Simulation Monte Carlo of Gaseous Flow and Heat Transfer in Micro channel written by Riad Sayegh and published by . This book was released on 1999 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Heat Transfer and Fluid Flow in Minichannels and Microchannels written by Satish Kandlikar and published by Elsevier. This book was released on 2006 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt: &Quot;This book explores flow through passages with hydraulic diameters from about 1 [mu]m to 3 mm, covering the range of minichannels and microchannels. Design equations along with solved examples and practice problems are also included to serve the needs of practicing engineers and students in a graduate course."--BOOK JACKET.
Download or read book Investigation of Supersonic Gas Flows Into Nanochannels Using an Unstructured 3D Direct Simulation Monte Carlo Method written by Wael G. Al-Kouz and published by . This book was released on 2009 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: This dissertation is devoted to the computational investigation of supersonic gas flows in rectangular nanochannels with scales between 100 nm and 1000 nm, using an unstructured three-dimensional Direct Simulation Monte Carlo (U3DSMC) methodology. This dissertation also contributes to the computational mathematics background of the U3DSMC method with validations and verifications at the micronscale and nanoscale, as well as with the investigation of the statistical fluctuations and errors associated with U3DSMC simulations at the nanoscale. The U3DSMC code is validated by comparisons with previous two dimensional DSMC simulations of flows in micron-scale rectangular channels. The simulation involves the supersonic flow of nitrogen into a microchannel with height of 1.2 m and width of 6 m. The free stream conditions correspond to a pressure of 72,450 Pa, Mach number, Knudsen number and mean free path nm. The U3DSMC centerline temperature, heat flux to the wall, and mean velocity as a function of the transverse direction are in very good agreement with previous 2D results. Statistical fluctuations and errors in U3DSMC have added significance in nanoscale domains because the number of real particles can be very small inside a computational cell. The effect of the number of samples, the number of computational particles in a Delaunay cell, and the Mach number on the fractional errors of density, velocity and temperature are investigated for uniform and pressure-driven nanoscale flows. The uniform nanoflow is implemented by applying a and free stream boundary condition with m-3, K, nm in a domain that requires resolution of a characteristic length scale nm. The pressure-driven flows consider a nanochannel of 500 nm height, 100 nm width and 4 m length. Subsonic boundary conditions are applied with inlet pressure 101,325 Pa and outlet pressure of 10132.5 Pa. The analysis shows that U3DSMC simulations at nanoscales featuring 10-30 particles per Delaunay cell result in statistical errors that are consistent with theoretical estimates. The rarefied flow of nitrogen with speed ratio of 2, 5, and 10, pressure of 10.132 kPa into rectangular nanochannels with height of 100, 500 and 1000 nm is investigated using U3DSMC. The investigation considers rarefaction effects with =0.481, 0.962, 4.81, geometric effects with nanochannel aspect ratios of (L/H) from AR=1, 10, 100 and back-pressure effects with imposed pressures from 0 to 200 kPa. The computational domain features a buffer region upstream of the inlet and the nanochannel walls are assumed to be diffusively reflecting at the free stream temperature of 273 K. The analysis is based on the phase space distributions as well as macroscopic flow variables sampled in cells along the centerline. The phase space distributions show the formation of a disturbance region ahead of the inlet due to slow particles backstreaming through the inlet and the formation of a density enhancement with its maximum inside the nanochannel. The velocity phase-space distributions show a low-speed particle population generated inside the nanochannel due to wall collisions which is superimposed with the free stream high-speed population. The mean velocity decreases, while the number density increases in the buffer region. The translational temperature increases in the buffer region and reaches its maximum near the inlet. For AR=10 and 100 nanochannels the gas reaches near equilibrium with the wall temperature. The heat transfer rate is largest near the inlet region where non-equilibrium effects are dominant. For =0.481, 0.962, 4.81, vacuum back pressure, and AR=1, the nanoflow is supersonic throughout the nanochannel, while for AR=10 and 100, the nanoflow is subsonic at the inlet and becomes sonic at the outlet. For =0.962, AR=1, and imposed back pressure of 120 kPa and 200 kPa, the nanoflow becomes subsonic at the outlet. For =0.962 and AR=10, the outlet pressure nearly matches the imposed back pressure with the nanoflow becoming sonic at 40 kPa and subsonic at 100 kPa. Heat transfer rates at the inlet and mass flow rates at the outlet are in good agreement with those obtained from theoretical free-molecular models. The flows in these nanochannels share qualitative characteristics found in microchannels ad well as continuum compressible flows in channels with friction and heat loss. The rarefied flow of nitrogen with speed ratio of 2, 5, 10, at an atmospheric pressure of 101.32 kPa into rectangular nanochannels with height of 100 and 500 nm is investigated using U3DSMC. The investigation considers rarefaction effects with =0.0962 and 4.81, geometric effects with nanochannel aspect ratios of (L/H) of AR=1 and 10 and vacuum back-pressure. Phase plots and sample-averaged macroscopic parameters are used in the analysis. Under vacuum back pressure the centerline velocity decreases in the buffer region from its free stream value. For 0.481, 0.0962 and AR=1 the Mach number is supersonic at the inlet and remains supersonic throughout the nanochannel. For 0.481, 0.0962 and AR=10, the flow becomes subsonic at the inlet and shows a sharp increase in pressure. The Mach number, subsequently, increases and reaches the sonic point at the outlet. For 0.481, 0.0962 and AR=1 the translational temperature reaches a maximum near the inlet and decreases monotonically up to the outlet. For 0.481, 0.0962 and AR=10, the translational temperature reaches a maximum near the inlet and then decreases to come in near equilibration with the wall temperature of 273 K.
Download or read book Direct Simulation Monte Carlo DSMC Analysis of Gaseous Flows in Micro nano Channels written by Radhakrishna Rajagopal and published by . This book was released on 2007 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Microscale and Nanoscale Heat Transfer written by C.B. Sobhan and published by CRC Press. This book was released on 2008-06-12 with total page 317 pages. Available in PDF, EPUB and Kindle. Book excerpt: Through analyses, experimental results, and worked-out numerical examples, Microscale and Nanoscale Heat Transfer: Fundamentals and Engineering Applications explores the methods and observations of thermophysical phenomena in size-affected domains. Compiling the most relevant findings from the literature, along with results from their own re
Download or read book Comparisons of Continuum and Direct Simulation Monte Carlo Calculations of Two dimensional Heat Transfer Rarefied Gases written by Wei Rong and published by . This book was released on 1999 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Microscale Flow and Heat Transfer written by Amit Agrawal and published by Springer. This book was released on 2019-05-25 with total page 365 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers concepts and the latest developments on microscale flow and heat transfer phenomena involving a gas. The book is organised in two parts: the first part focuses on the fluid flow and heat transfer characteristics of gaseous slip flows. The second part presents modelling of such flows using higher-order continuum transport equations. The Navier-Stokes equations based solution is provided to various problems in the slip regime. Several interesting characteristics of slip flows along with useful empirical correlations are documented in the first part of the book. The examples bring out the failure of the conventional equations to adequately describe various phenomena at the microscale. Thereby the readers are introduced to higher order continuum transport (Burnett and Grad) equations, which can potentially overcome these limitations. A clear and easy to follow step by step derivation of the Burnett and Grad equations (superset of the Navier-Stokes equations) is provided in the second part of the book. Analytical solution of these equations, the latest developments in the field, along with scope for future work in this area are also brought out. Presents characteristics of flow in the slip and transition regimes for a clear understanding of microscale flow problems; Provides a derivation of Navier-Stokes equations from microscopic viewpoint; Features a clear and easy to follow step-by-step approach to derive Burnett and Grad equations; Describes a complete compilation of few known exact solutions of the Burnett and Grad equations, along with a discussion of the solution aided with plots; Introduces the variants of the Navier-Stokes, Burnett and Grad equations, including the recently proposed Onsager-Burnett and O13 moment equations.
Download or read book Monte Carlo Methods in Mechanics of Fluid and Gas written by Oleg Mikhaĭlovich Belot︠s︡erkovskiĭ and published by World Scientific. This book was released on 2010 with total page 281 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is devoted to analysis of Monte Carlo methods developed in rarefied gas dynamics. Presented is the short history of the development of such methods, described are their main properties, their advantages and deficiencies. It is shown that the contemporary stage in the progress of computational methods cannot be regarded without a complex approach to the preparation of algorithms taking into account all the peculiarities of the problem under consideration, that is, of the physical nature of a process, the mathematical model and the theoretical aspects of computational mathematics and stochastic processes. Thoroughly investigated is the possibility of application of Monte Carlo methods in some kindred areas of science which are non-traditional for the use of statistical modeling (continuous media, turbulence). Considered are the possible directions of development of statistical modeling.
Download or read book Heat Convection in Micro Ducts written by Yitshak Zohar and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: As the field of Microsystems expands into more disciplines and new applications such as RF-MEMS, Optical MEMS and Bio-MEMS, thermal management is becoming a critical issue in the operation of many microdevices, including microelectronic chips. Heat Convection in Micro Ducts focuses on the fundamental physics of convective heat transfer in microscale and specific applications such as: microchannel heat sinks, micro heat pipes, microcoolers and micro capillary pumped loops. This book will be of interest to the professional engineer and graduate student interested in learning about heat removal and temperature control in advanced integrated circuits and microelectromechanical systems.
Download or read book Microfluid Mechanics written by William Liou and published by McGraw Hill Professional. This book was released on 2005-09-07 with total page 369 pages. Available in PDF, EPUB and Kindle. Book excerpt: Publisher's Note: Products purchased from Third Party sellers are not guaranteed by the publisher for quality, authenticity, or access to any online entitlements included with the product. The rapid progress in fabricating and utilizing microelectromechanical (MEMS) systems during the last decade is not matched by corresponding understanding of the unconventional fluid flow involved in the operation and manufacture of these small devices. Providing such understanding is crucial to designing, optimizing, fabricating and operating improved MEMS devices. Microfluid Mechanics: Principles and Modeling is a rigorous reference that begins with the fundamental principles governing microfluid mechanics and progresses to more complex mathematical models, which will allow research engineers to better measure and predict reactions of gaseous and liquids in microenvironments.
Download or read book Gas Flows in Microsystems written by Lucien Baldas and published by MDPI. This book was released on 2019-10-28 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: The last two decades have witnessed a rapid development of microelectromechanical systems (MEMS) involving gas microflows in various technical fields. Gas microflows can, for example, be observed in microheat exchangers designed for chemical applications or for cooling of electronic components, in fluidic microactuators developed for active flow control purposes, in micronozzles used for the micropropulsion of nano and picosats, in microgas chromatographs, analyzers or separators, in vacuum generators and in Knudsen micropumps, as well as in some organs-on-a-chip, such as artificial lungs. These flows are rarefied due to the small MEMS dimensions, and the rarefaction can be increased by low-pressure conditions. The flows relate to the slip flow, transition or free molecular regimes and can involve monatomic or polyatomic gases and gas mixtures. Hydrodynamics and heat and mass transfer are strongly impacted by rarefaction effects, and temperature-driven microflows offer new opportunities for designing original MEMS for gas pumping or separation. Accordingly, this Special Issue seeks to showcase research papers, short communications, and review articles that focus on novel theoretical and numerical models or data, as well as on new experimental results and technics, for improving knowledge on heat and mass transfer in gas microflows. Papers dealing with the development of original gas MEMS are also welcome.
Download or read book Heat Exchangers written by Sadik Kakaç and published by CRC Press. This book was released on 2020-01-21 with total page 547 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presents a systematic approach to heat exchangers, focusing on fundamentals and applications Provides realistic design examples to enable instructors to assign thermal design projects to students Adds new or updated coverage of gasketed, compact and microscale heat exchangers Covers both single-phase and two-phase forced convection correlations Includes Figure Slides and a complete Solutions Manual for instructor adopting the text
Download or read book Microfluidics and Nanofluidics Handbook written by Sushanta K. Mitra and published by CRC Press. This book was released on 2011-09-20 with total page 1103 pages. Available in PDF, EPUB and Kindle. Book excerpt: This comprehensive handbook presents fundamental aspects, fabrication techniques, introductory materials on microbiology and chemistry, measurement techniques, and applications of microfluidics and nanofluidics. The first volume of the handbook focuses on physics and transport phenomena along with life sciences and related applications. It provides newcomers with the fundamental science background required for the study of microfluidics and nanofluidics. In addition, the advanced techniques and concepts described in the text will benefit experienced researchers and professionals.
Download or read book Microscale Heat Transfer Fundamentals and Applications written by S. Kakaç and published by Springer Science & Business Media. This book was released on 2006-05-20 with total page 517 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains an archival record of the NATO Advanced Institute on Microscale Heat Transfer – Fundamental and Applications in Biological and Microelectromechanical Systems held in Çesme – Izmir, Turkey, July 18–30, 2004. The ASIs are intended to be high-level teaching activity in scientific and technical areas of current concern. In this volume, the reader may find interesting chapters and various Microscale Heat Transfer Fundamental and Applications. The growing use of electronics, in both military and civilian applications has led to the widespread recognition for need of thermal packaging and management. The use of higher densities and frequencies in microelectronic circuits for computers are increasing day by day. They require effective cooling due to heat generated that is to be dissipated from a relatively low surface area. Hence, the development of efficient cooling techniques for integrated circuit chips is one of the important contemporary applications of Microscale Heat Transfer which has received much attention for cooling of high power electronics and applications in biomechanical and aerospace industries. Microelectromechanical systems are subject of increasing active research in a widening field of discipline. These topics and others are the main themeof this Institute.
Download or read book Computational heat and mass transfer CHMT 2001 Vol II written by and published by Editora E-papers. This book was released on with total page 369 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Heat Transfer in Aerospace Applications written by Bengt Sundén and published by Academic Press. This book was released on 2016-10-19 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: Heat Transfer in Aerospace Applications is the first book to provide an overall description of various heat transfer issues of relevance for aerospace applications. The book contains chapters relating to convection cooling, heat pipes, ablation, heat transfer at high velocity, low pressure and microgravity, aircraft heat exchangers, fuel cells, and cryogenic cooling systems. Chapters specific to low density heat transfer (4) and microgravity heat transfer (9) are newer subjects which have not been previously covered. The book takes a basic engineering approach by including correlations and examples that an engineer needs during the initial phases of vehicle design or to quickly analyze and solve a specific problem. Designed for mechanical, chemical, and aerospace engineers in research institutes, companies, and consulting firms, this book is an invaluable resource for the latest on aerospace heat transfer engineering and research. - Provides an overall description of heat transfer issues of relevance for aerospace applications - Discusses why thermal problems arise and introduces the various heat transfer modes - Helps solve the problem of selecting and calculating the cooling system, the heat exchanger, and heat protection - Features a collection of problems in which the methods presented in the book can be used to solve these problems
Download or read book Microfluidics and Nanofluidics Handbook 2 Volume Set written by Sushanta K. Mitra and published by CRC Press. This book was released on 2011-09-20 with total page 1767 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive, two-volume handbook on Microfluidics and Nanofluidics, this text covers fundamental aspects, fabrication techniques, introductory materials on microbiology and chemistry, measurement techniques, and applications with special emphasis on the energy sector. Each chapter begins with introductory coverage to a subject and then narrows in on advanced techniques and concepts, thus making it valuable to students and practitioners. The author pays special attention to applications of microfluidics in the energy sector and provides insight into the world of opportunities nanotechnology has to offer. Figures, tables, and equations to illustrate concepts.
