Download or read book Multiple relaxation time Lattice Boltzmann Simulations of Turbulent Pipe Flows written by Harish Opadrishta and published by . This book was released on 2016 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt: Turbulent pipe flows are encountered in a multitude of engineering applications. Some of the examples include removal of moisture, odors, and other harmful gases using exhaust pipes; transporting crude oil and cooling water in oil reneries; circulation of coolants through the engine in automobiles and motorcycles; etc. They have been studied experimentally for more than a century and by direct numerical simulations (DNS) for more than two decades. Over the past twenty years, there has been an increase in the involvement of computation in studying turbulent flows, including turbulent pipe flows. The low cost and time consumption of computer simulations, along with the ability to study complex dynamic processes that are practically intractable at all scales, have resulted in the increase in their use in research. At the same time, the presence of curved boundary remains a challenge for accurate DNS of this simple flow. ☐ In the recent past, lattice Boltzmann method (LBM) has emerged as an attractive option for simulating wall-bounded turbulent flows. It offers several advantages compared to the conventional models of computational fluid dynamics, due to the local nature of operations involved and easy implementation of boundary conditions. Despite the advantages posed by the LBM, no DNS of turbulent pipe flow has been reported using LBM. Hence, the objective of this study is to develop a lattice Boltzmann model to simulate turbulent pipe flow and implement it into a computer code using FORTRAN and MPI. This code is then used to simulate fully developed turbulent pipe flow and validate the results with the existing benchmark data. ☐ In this thesis, the lattice Boltzmann model in three spatial dimensions using 27 mesoscopic velocities on a cubic grid was designed using an "inverse design" analysis. Yu et al.'s double interpolation scheme was used to satisfy the no-slip condition at the solid-liquid interface. ☐ The code was first validated by simulating laminar channel and pipe flows. The profiles of streamwise velocity for the laminar pipe and channel flow simulations were observed to be in excellent agreement with the analytical results. Further, the results of the time evolution of the centerline streamwise velocity for the laminar pipe and channel flow also matched the analytical results. Hence, the validity and accuracy of the code was established. ☐ Turbulent pipe flow was then simulated using the D3Q27 model. The first and second order statistics of the turbulent pipe flow simulation from the D3Q27, D3Q19 model were compared with the reference data being obtained from the spectral and finite volume discretizations of the Navier-Stokes equation. The mean velocity profiles of the D3Q27 simulation matched well with the reference data. On the other hand, the D3Q19 model under-predicts the mean velocity, especially near the center. In addition, the contours of the streamwise velocity for the D3Q19 simulation showed a certain preference along particular directions. This was not observed in the D3Q27 simulation. The erroneous results of the D3Q19 model could be explained by the hypothesis stated in White et al., stating that the presence of "defective planes" could be a plausible reason for the errors in the measurement of streamwise velocity in the D3Q19 model. Hence, the D3Q27 model seems like a suitable option to simulate wall-bounded turbulent flows with a curved boundary. The only drawback to using the D3Q27 model is its slower execution speed as it takes 21% more CPU time than the D3Q19 model.
Download or read book Simulations of Turbulent Flow Over Periodic Hills with Multiple relaxation time Lattice Boltzmann Method on Multi GPU Cluster written by Xiao-Ying Huang and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Double Population Multi relaxation Time Lattice Boltzmann Method for Turbulent Mixed Convection Particulate Flow Simulation written by Leila Jahanshaloo and published by . This book was released on 2015 with total page 325 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Lattice Boltzmann Modeling written by Michael C. Sukop and published by Springer Science & Business Media. This book was released on 2007-04-05 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt: Here is a basic introduction to Lattice Boltzmann models that emphasizes intuition and simplistic conceptualization of processes, while avoiding the complex mathematics that underlies LB models. The model is viewed from a particle perspective where collisions, streaming, and particle-particle/particle-surface interactions constitute the entire conceptual framework. Beginners and those whose interest is in model application over detailed mathematics will find this a powerful 'quick start' guide. Example simulations, exercises, and computer codes are included.
Download or read book Lattice Boltzmann Method And Its Application In Engineering written by Zhaoli Guo and published by World Scientific. This book was released on 2013-03-25 with total page 419 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lattice Boltzmann method (LBM) is a relatively new simulation technique for the modeling of complex fluid systems and has attracted interest from researchers in computational physics. Unlike the traditional CFD methods, which solve the conservation equations of macroscopic properties (i.e., mass, momentum, and energy) numerically, LBM models the fluid consisting of fictive particles, and such particles perform consecutive propagation and collision processes over a discrete lattice mesh.This book will cover the fundamental and practical application of LBM. The first part of the book consists of three chapters starting form the theory of LBM, basic models, initial and boundary conditions, theoretical analysis, to improved models. The second part of the book consists of six chapters, address applications of LBM in various aspects of computational fluid dynamic engineering, covering areas, such as thermo-hydrodynamics, compressible flows, multicomponent/multiphase flows, microscale flows, flows in porous media, turbulent flows, and suspensions.With these coverage LBM, the book intended to promote its applications, instead of the traditional computational fluid dynamic method.
Download or read book Handbook of HydroInformatics written by Saeid Eslamian and published by Elsevier. This book was released on 2022-12-06 with total page 422 pages. Available in PDF, EPUB and Kindle. Book excerpt: Handbook of HydroInformatics Volume III: Water Data Management Best Practices presents the latest and most updated data processing techniques that are fundamental to Water Science and Engineering disciplines. These include a wide range of the new methods that are used in hydro-modeling such as Atmospheric Teleconnection Pattern, CONUS-Scale Hydrologic Modeling, Copula Function, Decision Support System, Downscaling Methods, Dynamic System Modeling, Economic Impacts and Models, Geostatistics and Geospatial Frameworks, Hydrologic Similarity Indices, Hydropower/Renewable Energy Models, Sediment Transport Dynamics Advanced Models, Social Data Mining, and Wavelet Transforms. This volume is an example of true interdisciplinary work. The audience includes postgraduates and above interested in Water Science, Geotechnical Engineering, Soil Science, Civil Engineering, Chemical Engineering, Computer Engineering, Engineering, Applied Science, Earth and Geoscience, Atmospheric Science, Geography, Environment Science, Natural Resources, Mathematical Science, and Social Sciences. It is a fully comprehensive handbook which provides all the information needed related to the best practices for managing water data. Contributions from global experts in the fields of data management research, climate change and resilience, insufficient data problem, etc. Thorough applied examples and case studies in each chapter, providing the reader with real world scenarios for comparison. Includes a wide range of new methods that are used in hydro-modeling, with step-by-step guides on how to use them.
Download or read book The Lattice Boltzmann Method written by Timm Krüger and published by Springer. This book was released on 2016-11-07 with total page 705 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is an introduction to the theory, practice, and implementation of the Lattice Boltzmann (LB) method, a powerful computational fluid dynamics method that is steadily gaining attention due to its simplicity, scalability, extensibility, and simple handling of complex geometries. The book contains chapters on the method's background, fundamental theory, advanced extensions, and implementation. To aid beginners, the most essential paragraphs in each chapter are highlighted, and the introductory chapters on various LB topics are front-loaded with special "in a nutshell" sections that condense the chapter's most important practical results. Together, these sections can be used to quickly get up and running with the method. Exercises are integrated throughout the text, and frequently asked questions about the method are dealt with in a special section at the beginning. In the book itself and through its web page, readers can find example codes showing how the LB method can be implemented efficiently on a variety of hardware platforms, including multi-core processors, clusters, and graphics processing units. Students and scientists learning and using the LB method will appreciate the wealth of clearly presented and structured information in this volume.
Download or read book Lattice Boltzmann Simulation of Laminar and Turbulent Two phase Flows written by Amir Eshghinejadfard and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Lattice Boltzmann Simulations of Environmental Flow Problems in Shallow Water Flows written by Yong Peng and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The lattice Boltzmann method (LBM) proposed about decades ago has been developed and applied to simulate various complex fluids. It has become an alternative powerful method for computational fluid dynamics (CFD). Although most research on the LBM focuses on the Navier-Stokes equations, the method has also been developed to solve other flow equations such as the shallow water equations. In this thesis, the lattice Boltzmann models for the shallow water equations and solute transport equation have been improved and applied to different flows and environmental problems, including solute transport and morphological evolution. In this work, both the single-relaxation-time and multiple-relaxation-time models are used for shallow water equations (named LABSWE and LABSWEMRT, respectively), and the large eddy simulation is incorporated into the LABSWE (named LABSWETM) for turbulent flow. The capability of the LABSWETM was firstly tested by applying it to simulate free surface flows in rectangular basins with different length -width ratios, in which the characteristics of the asymmetrical flows were studied in details. The LABSWEMRT was then used to simulate the one- and two-dimensional shallow water flows over discontinuous beds. The weighted centred scheme for force term, together with the bed height for a bed slope, was incorporated into the model to improve the simulation of water flows over a discontinuous bed. The resistance stress was also included to investigate the effect of the local head loss caused by flows over a step. Thirdly, the LABSWEMRT was extended to simulate a moving body in shallow water. In order to deal with the moving boundaries, three different schemes with second-order accuracy were tested and compared for treating curved boundaries. An additional momentum term was added to reflect the interaction between the following fluid and the solid, and a refilled method was proposed to treat the wetted nodes moving out from the solid nodes. Fourthly, both LABSWE and LABSWEMRT were used to investigate solute transport in shallow water. The flows are solved using LABSWE and LABSWEMRT, and the advection-diffusion equation for solute transport was solved with a LBM-BGK model based on the D2Q5 lattice. Three cases: open channel flow with a side discharge, shallow recirculation flow and flow in a harbour, were simulated to verify the methods. In addition, the performance of LABSWEMRT and LABSWE were compared, and the results showed that the LABSWMRT has better stability and can be used for flow with high Reynolds number. Finally, the lattice Boltzmann method was used with the Euler-WENO scheme to simulate morphological evolution in shallow water. The flow fields were solved by the LABSWEMRT with the improved scheme for the force term, and the fifth order Euler-WENO scheme was used to solve the morphological equation to predict the morphological evolution caused by the bed-load transport.
Download or read book Lattice Gas Cellular Automata and Lattice Boltzmann Models written by Dieter A. Wolf-Gladrow and published by Springer. This book was released on 2004-10-19 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lattice-gas cellular automata (LGCA) and lattice Boltzmann models (LBM) are relatively new and promising methods for the numerical solution of nonlinear partial differential equations. The book provides an introduction for graduate students and researchers. Working knowledge of calculus is required and experience in PDEs and fluid dynamics is recommended. Some peculiarities of cellular automata are outlined in Chapter 2. The properties of various LGCA and special coding techniques are discussed in Chapter 3. Concepts from statistical mechanics (Chapter 4) provide the necessary theoretical background for LGCA and LBM. The properties of lattice Boltzmann models and a method for their construction are presented in Chapter 5.
Download or read book Lattice Boltzmann Method for Simulating Turbulent Flows written by Yusuke Koda and published by . This book was released on 2013 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: The lattice Boltzmann method (LBM) is a relatively new method for fluid flow simulations, and is recently gaining popularity due to its simple algorithm and parallel scalability. Although the method has been successfully applied to a wide range of flow physics, its capabilities in simulating turbulent flow is still under-validated. Hence, in this project, a 3D LBM program was developed to investigate the validity of the LBM for turbulent flow simulations through large eddy simulations (LES).
Download or read book A Generalized Wall Function written by and published by . This book was released on 1999 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Validation of the Lattice Boltzmann Method for Direct Numerical Simulation of Wall bounded Turbulent Flows written by Dustin John Bespalko and published by . This book was released on 2011 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this work, the lattice Boltzmann method (LBM) was validated for direct numerical simulation (DNS) of wall-bounded turbulent flows. The LBM is a discrete-particle-based method that numerically solves the Boltzmann equation as opposed to conventional DNS methods that are based on the Navier-Stokes (NS) equations. The advantages of the LBM are its simple implementation, its ability to handle complex geometries, and its scalability on modern high-performance computers. An LBM code was developed and used to simulate fully-developed turbulent channel flow. In order to validate the results, the turbulence statistics were compared to those calculated from a conventional NS-based finite difference (FD) simulation. In the present study, special care was taken to make sure the computational domains for LBM and FD simulations were the same. Similar validation studies in the literature have used LBM simulations with smaller computational domains in order to reduce the computational cost. However, reducing the size of the computational domain affects the turbulence statistics and confounds the results of the validation. The turbulence statistics calculated from the LBM and FD simulations were found to agree qualitatively; however, there were several significant deviations, particularly in the variance profiles. The largest discrepancy was in the variance of the pressure fluctuations, which differed by approximately 7%. Given that both the LBM and FD simulations resolved the full range of turbulent scales and no models were used, this error was deemed to be significant. The cause of the discrepancy in the pressure variance was found to be the compressibility of the LBM. The LBM allows the density to vary, while the FD method does not since it solves the incompressible form of the NS equations. The effect of the compressibility could be reduced by lowering the Mach number, but this would come at the cost of significantly increasing the computational cost. Therefore, the conclusion of this work is that, while the LBM is capable of producing accurate solutions for incompressible turbulent flows, it is significantly more expensive than conventional methods for simple wall-bounded turbulent flows.
Download or read book Advanced Mechanical Science and Technology for the Industrial Revolution 4 0 written by Ligang Yao and published by Springer. This book was released on 2017-10-30 with total page 333 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book includes more than 30 papers from the first FZU-OPU-NTOU Joint Symposium on Advanced Mechanical Science and Technology for the Industrial Revolution 4.0, held at Fuzhou University, China, in December 2016. The symposium was organized by Fuzhou University (FZU), Osaka Prefecture University (OPU) and National Taiwan Ocean University (NTOU). The authors include several professors from universities in China, Japan, and Taiwan as well as four distinguished invited professors from Canada, Korea, Japan, and Taiwan. The book covers all important aspects related to the 4.0 industrial revolution: robotics and mechatronics; sensors, measurements, and instrumentation; mechanical dynamics and controls; mechanical design; vehicle systems and technologies; fluid mechanics; monitoring and diagnosis, prognosis, and health management; advanced signal processing; and big data; all of which are subjects with great potential in the field of mechanical engineering.
Download or read book Kinetic Theory and Fluid Dynamics written by Yoshio Sone and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt: This monograph is intended to provide a comprehensive description of the rela tion between kinetic theory and fluid dynamics for a time-independent behavior of a gas in a general domain. A gas in a steady (or time-independent) state in a general domain is considered, and its asymptotic behavior for small Knudsen numbers is studied on the basis of kinetic theory. Fluid-dynamic-type equations and their associated boundary conditions, together with their Knudsen-layer corrections, describing the asymptotic behavior of the gas for small Knudsen numbers are presented. In addition, various interesting physical phenomena derived from the asymptotic theory are explained. The background of the asymptotic studies is explained in Chapter 1, accord ing to which the fluid-dynamic-type equations that describe the behavior of a gas in the continuum limit are to be studied carefully. Their detailed studies depending on physical situations are treated in the following chapters. What is striking is that the classical gas dynamic system is incomplete to describe the behavior of a gas in the continuum limit (or in the limit that the mean free path of the gas molecules vanishes). Thanks to the asymptotic theory, problems for a slightly rarefied gas can be treated with the same ease as the corresponding classical fluid-dynamic problems. In a rarefied gas, a temperature field is di rectly related to a gas flow, and there are various interesting phenomena which cannot be found in a gas in the continuum limit.
Download or read book Lattice Boltzmann Modeling of Complex Flows for Engineering Applications written by Andrea Montessori and published by Morgan & Claypool Publishers. This book was released on 2018-02-20 with total page 109 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nature continuously presents a huge number of complex and multi-scale phenomena, which in many cases, involve the presence of one or more fluids flowing, merging and evolving around us. Since its appearance on the surface of Earth, Mankind has tried to exploit and tame fluids for their purposes, probably starting with Hero's machinery to open the doors of the Temple of Serapis in Alexandria to arrive to modern propulsion systems and actuators. Today we know that fluid mechanics lies at the basis of countless scientific and technical applications from the smallest physical scales (nanofluidics, bacterial motility, and diffusive flows in porous media), to the largest (from energy production in power plants to oceanography and meteorology). It is essential to deepen the understanding of fluid behaviour across scales for the progress of Mankind and for a more sustainable and efficient future. Since the very first years of the Third Millennium, the Lattice Boltzmann Method (LBM) has seen an exponential growth of applications, especially in the fields connected with the simulation of complex and soft matter flows. LBM, in fact, has shown a remarkable versatility in different fields of applications from nanoactive materials, free surface flows, and multiphase and reactive flows to the simulation of the processes inside engines and fluid machinery. LBM is based on an optimized formulation of Boltzmann's Kinetic Equation, which allows for the simulation of fluid particles, or rather quasi-particles, from a mesoscopic point of view thus allowing the inclusion of more fundamental physical interactions in respect to the standard schemes adopted with Navier-Stokes solvers, based on the continuum assumption. In this book, the authors present the most recent advances of the application of the LBM to complex flow phenomena of scientific and technical interest with particular focus on the multi-scale modeling of heterogeneous catalysis within nano-porous media and multiphase, multicomponent flows.
Download or read book Progress in Turbulence IX written by Ramis Örlü and published by Springer Nature. This book was released on 2021-10-23 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume collects the edited and reviewed contribution presented in the 9th iTi Conference that took place virtually, covering fundamental and applied aspects in turbulence. In the spirit of the iTi conference, the volume is produced after the conference so that the authors had the opportunity to incorporate comments and discussions raised during the meeting. In the present book, the contributions have been structured according to the topics: I Experiments II Simulations and Modelling III Data Processing and Scaling IV Theory V Miscellaneous topics
