Download or read book A Time Accurate Upwind Unstructured Finite Volume Method for Compressible Flow with Cure of Pathological Behaviors written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2019-01-13 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: A time-accurate, upwind, finite volume method for computing compressible flows on unstructured grids is presented. The method is second order accurate in space and time and yields high resolution in the presence of discontinuities. For efficiency, the Roe approximate Riemann solver with an entropy correction is employed. In the basic Euler/Navier-Stokes scheme, many concepts of high order upwind schemes are adopted: the surface flux integrals are carefully treated, a Cauchy-Kowalewski time-stepping scheme is used in the time-marching stage, and a multidimensional limiter is applied in the reconstruction stage. However even with these up-to-date improvements, the basic upwind scheme is still plagued by the so-called "pathological behaviors," e.g., the carbuncle phenomenon, the expansion shock, etc. A solution to these limitations is presented which uses a very simple dissipation model while still preserving second order accuracy. This scheme is referred to as the enhanced time-accurate upwind (ETAU) scheme in this paper. The unstructured grid capability renders flexibility for use in complex geometry; and the present ETAU Euler/Navier-Stokes scheme is capable of handling a broad spectrum of flow regimes from high supersonic to subsonic at very low Mach number, appropriate for both CFD (computational fluid dynamics) and CAA (computational aeroacoustics). Numerous examples are included to demonstrate the robustness of the methods. Loh, Ching Y. and Jorgenson, Philip C. E. Glenn Research Center NAS3-0372; WBS 561581.02.08.03.18.02

Download or read book Efficient High order Accurate Unstructured Finite volume Algorithms for Viscous and Inviscid Compressible Flows written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: High-order accurate methods have the potential to dramatically reduce the computational time needed for aerodynamics simulations. This thesis studies the discretization and efficient convergence to steady state of the high-order accurate finite-volume method applied to the simplified problem of inviscid and laminar viscous two-dimensional flow equations. Each of the three manuscript chapters addresses a specific problem or limitation previously experienced with these schemes. The first manuscript addresses the absence of a method to maintain monotonicity of the solution at discontinuities while maintaining high-order accuracy in smooth regions. To resolve this, a slope limiter is carefully developed which meets these requirements while also maintaining the good convergence properties and computational efficiency of the least-squares reconstruction scheme. The second manuscript addresses the relatively poor convergence properties of Newton-GMRES methods applied to high-order accurate schemes. The globalization of the Newton method is improved through the use of an adaptive local timestep and of a line search algorithm. The poor convergence of the linear solver is improved through the efficient assembly of the exact flux Jacobian for use in preconditioning and to eliminate the additional residual evaluations needed by a matrix-free method. The third manuscript extends the discretization method to the viscous fluxes and boundary conditions. The discretization is demonstrated to achieve the expected order of accuracy. The fourth-order scheme is also shown to be more computationally efficient than the second-order scheme at achieving grid-converged values of drag for two-dimensional laminar flow over an airfoil.

Download or read book An Implicit Finite Volume Method for Compressible Turbulent Flows on Unstructured Meshes written by Philippe Geuzaine and published by . This book was released on 1999 with total page 185 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Finite Volume Methods for Incompressible Flow written by Darryl M. Whitlow and published by . This book was released on 2001 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Robust and Efficient Finite Volume Method for Compressible Two Phase Flows at All Speeds on Unstructured Grids written by Aditya Kiran Pandare and published by . This book was released on 2018 with total page 131 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Unstructured Finite Volume Algorithms for Compressible Multiphase Flow written by Gerard Serge Bruno Lebon and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This research presents novel algorithms for computing flow within an unstructured, collocated, finite volume solver in the presence of non-orthogonality and compressibility in order to extend the range of problems which can be modelled with the University's in-house CFD code: PHYSICA. A new non-orthogonality diffusion correction relaxation parameter has been successfully introduced and tested with benchmarks from the literature. Cases involving geometries meshed with commercial packages have been successfully run with the diffusion correction methods, variable bounding and proper under-relaxation practices. The applicability of a pressure interpolation method has also been tested with these cases. A procedure for solving compressible flow within a finite volume, pressure correction type scheme, has been devised and successfully implemented in different test cases. This method is however prone to numerical diffusion in the presence of shocks, but does work even in the presence of skewed meshes. The method was then tested with the case of an oxygen jet entering a heated furnace, for which experimental data is available for comparison. The method was successful in predicting the axial variables of the jet, and used to develop a turbulence modification model for such jets. The method was finally used to model the deformation of a free surface impinged by a compressible jet, using a novel zonal method called zonal Gas And Liquid Analyser (GALA). Convergence was achieved with the method developed in this research, together with the application of the counter diffusion method to model the moving interface.

Download or read book A Mass weighted Upwind based Control Volume Finite element Method for Steady Two dimensional Viscous Compressible Flows written by Hao Zhou and published by . This book was released on 1997 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development and Application of a Finite Volume Method for the Computation of Flows Around Moving Bodies on Unstructured Overlapping Grids written by Hidajet Hadžić and published by . This book was released on 2006 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book International Aerospace Abstracts written by and published by . This book was released on 1998 with total page 920 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Generalized Riemann Problems in Computational Fluid Dynamics written by Matania Ben-Artzi and published by Cambridge University Press. This book was released on 2003-04-10 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: Numerical simulation of compressible, inviscid time-dependent flow is a major branch of computational fluid dynamics. Its primary goal is to obtain accurate representation of the time evolution of complex flow patterns, involving interactions of shocks, interfaces, and rarefaction waves. The Generalized Riemann Problem (GRP) algorithm, developed by the authors for this purpose, provides a unifying 'shell' which comprises some of the most commonly used numerical schemes of this process. This monograph gives a systematic presentation of the GRP methodology, starting from the underlying mathematical principles, through basic scheme analysis and scheme extensions (such as reacting flow or two-dimensional flows involving moving or stationary boundaries). An array of instructive examples illustrates the range of applications, extending from (simple) scalar equations to computational fluid dynamics. Background material from mathematical analysis and fluid dynamics is provided, making the book accessible to both researchers and graduate students of applied mathematics, science and engineering.

Download or read book Hyperbolic Problems written by Michael Fey and published by . This book was released on 1999 with total page 536 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Riemann Solvers and Numerical Methods for Fluid Dynamics written by Eleuterio F. Toro and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 635 pages. Available in PDF, EPUB and Kindle. Book excerpt: High resolution upwind and centered methods are today a mature generation of computational techniques applicable to a wide range of engineering and scientific disciplines, Computational Fluid Dynamics (CFD) being the most prominent up to now. This textbook gives a comprehensive, coherent and practical presentation of this class of techniques. The book is designed to provide readers with an understanding of the basic concepts, some of the underlying theory, the ability to critically use the current research papers on the subject, and, above all, with the required information for the practical implementation of the methods. Applications include: compressible, steady, unsteady, reactive, viscous, non-viscous and free surface flows.

Download or read book Parallel Computational Fluid Dynamics 2002 written by K. Matsuno and published by Elsevier. This book was released on 2003-04-25 with total page 621 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume is proceedings of the international conference of the Parallel Computational Fluid Dynamics 2002. In the volume, up-to-date information about numerical simulations of flows using parallel computers is given by leading researchers in this field. Special topics are "Grid Computing" and "Earth Simulator". Grid computing is now the most exciting topic in computer science. An invited paper on grid computing is presented in the volume. The Earth-Simulator is now the fastest computer in the world. Papers on flow-simulations using the Earth-Simulator are also included, as well as a thirty-two page special tutorial article on numerical optimization.

Download or read book Parallel Computational Fluid Dynamics 2006 written by Jang-Hyuk Kwon and published by Elsevier. This book was released on 2007-09-12 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: The proceedings from Parallel CFD 2006 covers all aspects of parallel computings and its applications. Although CFD is one of basic tools for design procedures to produce machineries, such as automobiles, ships, aircrafts, etc., large scale parallel computing has been realized very recently, especially for the manufactures. Various applications in many areas could be experienced including acoustics, weather prediction and ocean modeling, flow control, turbine flow, fluid-structure interaction, optimization, heat transfer, hydrodynamics.- Report on current research in the field in an area which is rapidly changing - Subject is important to all interested in solving large fluid dynamics problems - Interdisciplinary activity. Contributions include scientists with a variety of backgrounds

Download or read book Hyperbolic Problems written by American Institute of Mathematical Sciences and published by . This book was released on 2014 with total page 1069 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modern Compressible Flow written by John David Anderson and published by . This book was released on 2004 with total page 760 pages. Available in PDF, EPUB and Kindle. Book excerpt: Anderson's book provides the most accessible approach to compressible flow for Mechanical and Aerospace Engineering students and professionals. In keeping with previous versions, the 3rd edition uses numerous historical vignettes that show the evolution of the field.New pedagogical features--"Roadmaps" showing the development of a given topic, and "Design Boxes" giving examples of design decisions--will make the 3rd edition even more practical and user-friendly than before.The 3rd edition strikes a careful balance between classical methods of determining compressible flow, and modern numerical and computer techniques (such as CFD) now used widely in industry & research.A new Book Website will contain all problem solutions for instructors.

Download or read book Computational Fluid and Solid Mechanics 2003 written by K.J Bathe and published by Elsevier. This book was released on 2003-06-02 with total page 2485 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bringing together the world's leading researchers and practitioners of computational mechanics, these new volumes meet and build on the eight key challenges for research and development in computational mechanics.Researchers have recently identified eight critical research tasks facing the field of computational mechanics. These tasks have come about because it appears possible to reach a new level of mathematical modelling and numerical solution that will lead to a much deeper understanding of nature and to great improvements in engineering design.The eight tasks are: - The automatic solution of mathematical models - Effective numerical schemes for fluid flows - The development of an effective mesh-free numerical solution method - The development of numerical procedures for multiphysics problems - The development of numerical procedures for multiscale problems - The modelling of uncertainties - The analysis of complete life cycles of systems - Education - teaching sound engineering and scientific judgement Readers of Computational Fluid and Solid Mechanics 2003 will be able to apply the combined experience of many of the world's leading researchers to their own research needs. Those in academic environments will gain a better insight into the needs and constraints of the industries they are involved with; those in industry will gain a competitive advantage by gaining insight into the cutting edge research being carried out by colleagues in academia. Features - Bridges the gap between academic researchers and practitioners in industry - Outlines the eight main challenges facing Research and Design in Computational mechanics and offers new insights into the shifting the research agenda - Provides a vision of how strong, basic and exciting education at university can be harmonized with life-long learning to obtain maximum value from the new powerful tools of analysis