Download or read book Towards Improvement of Numerical Accuracy for Unstructured Grid Flow Solver written by Qiuying Zhao and published by . This book was released on 2012 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: An effort to improve the numerical accuracy of a three dimensional unstructured grid finite volume scheme is pursued in the present work. Unstructured grid methods have been widely used in computational fluid dynamics for the convenience of modeling complex geometries in realistic applications. In the present work, improvements towards high order unstructured grid schemes are proposed using high order flux formula for spatial discretizations. The Riemann variables on the left and right sides of the interface are reconstructed using quadratic and quartic polynomials composed of both flow variables and their gradients. The high order flux is then calculated using the concept of MUSCL (Monotone Upstream-centered Schemes for Conservation Laws) approach. In order to maintain the accuracy for the finite volume scheme, an innovative method based on Radial Basis Function interpolation is introduced as a substitution to Gaussian quadrature to achieve the higher order surface integration on mixed element unstructured grids. The proposed high order improvements for unstructured grid schemes have been tested for a wide range of flows from very low Mach number to supersonic speeds. The observed accuracy for the improved schemes is verified using a benchmark case about an inviscid vortex transporting in a free stream flow. In addition, the ability to capture the tip trailing vortex, which is a major challenge in computational fluid dynamics today, is extensively verified on two vortex dominated viscous flows, a fixed NACA0015 wing at a subsonic Mach number and a rotating NACA0012 hovering rotor at a transonic tip speed. The numerical validations are also performed on two realistic industrial applications including a marine propeller P5168 and a Bell Helicopter aircraft 427 main rotor. Computational results indicate that the methods proposed in the present work can significantly improve numerical accuracy in predicting the strong vortical flows in smooth regions, while maintaining the stability of the schemes in discontinuous regions such as shockwaves.
Download or read book Analysis and Improvement of the Accuracy of Unstructured Mesh Operators with Applications to an Unsteady Incompressible Flow Solver written by B. de Foy and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Recent Numerical Advances in Fluid Mechanics written by Omer San and published by MDPI. This book was released on 2020-07-03 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent decades, the field of computational fluid dynamics has made significant advances in enabling advanced computing architectures to understand many phenomena in biological, geophysical, and engineering fluid flows. Almost all research areas in fluids use numerical methods at various complexities: from molecular to continuum descriptions; from laminar to turbulent regimes; from low speed to hypersonic, from stencil-based computations to meshless approaches; from local basis functions to global expansions, as well as from first-order approximation to high-order with spectral accuracy. Many successful efforts have been put forth in dynamic adaptation strategies, e.g., adaptive mesh refinement and multiresolution representation approaches. Furthermore, with recent advances in artificial intelligence and heterogeneous computing, the broader fluids community has gained the momentum to revisit and investigate such practices. This Special Issue, containing a collection of 13 papers, brings together researchers to address recent numerical advances in fluid mechanics.
Download or read book High order Numerical Methods for Unstructured Grids and Sliding Mesh written by Gonzalo Sáez Mischlich and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: High-order numerical methods have proven to be an essential tool to improve the accuracy of simulations involving turbulent flows through the solution of conservation laws. Such flows appear in a wide variety of industrial applications and its correct prediction is crucial to reduce the power consumption and improve the efficiency of these processes. The present study implements and analyzes different types of high-order spatial discretization schemes for unstructured grids to assess and quantify their accuracy in simulations of turbulent flows. In particular, high-order Finite Volume methods (FVM) based on least squares and fully constrained deconvolution operators are considered and their accuracy is evaluated in a variety of linear and non-linear test cases and throughanalytical analysis. Special emphasis is placed on the comparison of formally second-order and high-order FVM, showing that the former can over-perform the latter in terms of accuracy and computational performance in under-resolved configurations. High-order Spectral Element methods (SEM), including Spectral Difference (SD) and Flux Reconstruction (FR), are compared in different linear and non-linear configurations. Furthermore, a SD GPU-based solver (based on the open-source PyFR solver) is developed and its performance with respect to other state of the art CPU-based solvers will be discussed, showing that the developed GPU-based solver outperforms other state of the art CPU-based solvers in terms of performance-per-euro and performance-per-watt. The accuracy and behavior of SEM under aliasing are assessed in linear test cases using analytical tools. The use of grids with high-order cells, which allow to better describe the surfaces of interests of a given simulation, in combination with SEM is also analyzed. The latter analysis demonstrates that special care must be taken to ensure appropriate numerical accuracy when utilizing meshes with such elements. This document also presents the development and the analysis of the Spectral Difference Raviart-Thomas (SDRT) method for two and three-dimensional tensor product and simplex elements. This method is equivalent to the SD formulation for tensor product elements and it can be considered as a natural extension of the SD formulation for simplex elements. Additionally, a new family of FR methods, which is equivalent to the SDRT method under certain circumstances, is described. All these developments were implemented in the open-source PyFR solver and are compatible with CPU and GPU architectures. In the context of high-order simulations of turbulent flows found in rotor-stator interaction test cases, a sliding mesh method (which involves non-conformal grids and mesh motion) specifically tailored for massivelyparallel simulations is implemented within a CPU-based solver. The developed method is compatible with second-order and high-order FVM and SEM. Grid movement, needed to simulate rotor-stator test cases due to the relative movement of each domain zone, is treated using the Arbitrary-Lagrangian-Eulerian (ALE) formulation. The analysis of such formulation depicts its important influence on the numerical accuracy and stability of numerical simulations with mesh motion. Moreover, specific non-conformal discretization methodscompatible with second-order and high-order FVM and SEM are developed and their accuracy is assessed on different non-linear test cases. The parallel scalability of the method is assessed with up to 11000 cores, proving appropriate computational efficiency. The accuracy of the implementation is assessed through a set of linear and non-linear test cases. Preliminary results of the turbulent flow around a DGEN 380 fan stage in an under-resolved configuration are shown and compared to available experimental data.
Download or read book Pressure based High Order Accuracy Flow Solver on Adaptive Mixed Type Unstructured Grids written by Y. Jiang and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 542 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Adaptive Solution of Viscous Aerodynamic Flows Using Unstructured Grids written by Paul Charles Walsh and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book New Results in Numerical and Experimental Fluid Mechanics XIV written by Andreas Dillmann and published by Springer Nature. This book was released on 2023-10-24 with total page 700 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers timely insights into research on numerical and experimental fluid mechanics and aerodynamics, mainly for (but not limited to) aerospace applications. It reports on findings by members of the Deutsche Strömungsmechanische Arbeitsgemeinschaft, STAB (German Aerodynamics/Fluid Mechanics Association) and the Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal Oberth e.V., DGLR (German Society for Aeronautics and Astronautics) and covers both nationally and EC-funded projects. Continuing on the tradition of the previous volumes, the book highlights innovative solutions, promoting translation from fundamental research to industrial applications. It addresses academics and professionals in the field of aeronautics, astronautics, ground transportation, and energy alike.
Download or read book Computational Fluid Dynamics for the 21st Century written by Mohamed Hafez and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains new trends of computational fluid dynamics for the 21st century and consists of papers especially useful to the younger generation of scientists and engineers in this field. Topics include cartesian, gridless and higher-order schemes, and flow-visualization techniques.
Download or read book 31st International Symposium on Shock Waves 1 written by Akihiro Sasoh and published by Springer. This book was released on 2019-03-21 with total page 1188 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first volume of a two volume set which presents the results of the 31st International Symposium on Shock Waves (ISSW31), held in Nagoya, Japan in 2017. It was organized with support from the International Shock Wave Institute (ISWI), Shock Wave Research Society of Japan, School of Engineering of Nagoya University, and other societies, organizations, governments and industry. The ISSW31 focused on the following areas: Blast waves, chemical reacting flows, chemical kinetics, detonation and combustion, ignition, facilities, diagnostics, flow visualization, spectroscopy, numerical methods, shock waves in rarefied flows, shock waves in dense gases, shock waves in liquids, shock waves in solids, impact and compaction, supersonic jet, multiphase flow, plasmas, magnetohyrdrodynamics, propulsion, shock waves in internal flows, pseudo-shock wave and shock train, nozzle flow, re-entry gasdynamics, shock waves in space, Richtmyer-Meshkov instability, shock/boundary layer interaction, shock/vortex interaction, shock wave reflection/interaction, shock wave interaction with dusty media, shock wave interaction with granular media, shock wave interaction with porous media, shock wave interaction with obstacles, supersonic and hypersonic flows, sonic boom, shock wave focusing, safety against shock loading, shock waves for material processing, shock-like phenomena, and shock wave education. These proceedings contain the papers presented at the symposium and serve as a reference for the participants of the ISSW 31 and individuals interested in these fields.
Download or read book NASA Technical Memorandum written by and published by . This book was released on 1994 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Efficient Implementation of High Order Accurate Numerical Methods on Unstructured Grids written by Wanai Li and published by . This book was released on 2014-06-30 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Canadian Aeronautics and Space Journal written by and published by . This book was released on 2000 with total page 664 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Twenty Second Symposium on Naval Hydrodynamics written by National Research Council and published by National Academies Press. This book was released on 2000-02-02 with total page 1039 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Twenty-Second Symposium on Naval Hydrodynamics was held in Washington, D.C., from August 9-14, 1998. It coincided with the 100th anniversary of the David Taylor Model Basin. This international symposium was organized jointly by the Office of Naval Research (Mechanics and Energy Conversion S&T Division), the National Research Council (Naval Studies Board), and the Naval Surface Warfare Center, Carderock Division (David Taylor Model Basin). This biennial symposium promotes the technical exchange of naval research developments of common interest to all the countries of the world. The forum encourages both formal and informal discussion of the presented papers, and the occasion provides an opportunity for direct communication between international peers.
Download or read book Equadiff 91 International Conference On Differential Equations In 2 Volumes written by C Perello and published by World Scientific. This book was released on 1993-05-25 with total page 1036 pages. Available in PDF, EPUB and Kindle. Book excerpt: Equadiff-91 stems from the series of conferences initiated by the late Professor Vogel. The first conference Equadiff-70 which was held in Marseille. Since then, similar conferences had been held in Brussels, Florence, Wurzburg as well as Xanthi. The purpose of the Equadiff series of conferences is to present the latest development in the field of differential equations, both ordinary and partial, including their numerical treatment and applications to the mathematics community. These conferences had attracted renowned mathematicians from all over the world to present their studies and findings. The latest conference under the series was Equadiff-91, held in Barcelona. It attracted some 30 renowned mathematicians. Researchers and graduate students of pure and applied mathematics will find this compilation of conference proceedings up-to-date, relevant and insightful.
Download or read book Computational Fluid Dynamics written by Frederic Magoules and published by CRC Press. This book was released on 2011-08-24 with total page 409 pages. Available in PDF, EPUB and Kindle. Book excerpt: Exploring new variations of classical methods as well as recent approaches appearing in the field, Computational Fluid Dynamics demonstrates the extensive use of numerical techniques and mathematical models in fluid mechanics. It presents various numerical methods, including finite volume, finite difference, finite element, spectral, smoothed particle hydrodynamics (SPH), mixed-element-volume, and free surface flow. Taking a unified point of view, the book first introduces the basis of finite volume, weighted residual, and spectral approaches. The contributors present the SPH method, a novel approach of computational fluid dynamics based on the mesh-free technique, and then improve the method using an arbitrary Lagrange Euler (ALE) formalism. They also explain how to improve the accuracy of the mesh-free integration procedure, with special emphasis on the finite volume particle method (FVPM). After describing numerical algorithms for compressible computational fluid dynamics, the text discusses the prediction of turbulent complex flows in environmental and engineering problems. The last chapter explores the modeling and numerical simulation of free surface flows, including future behaviors of glaciers. The diverse applications discussed in this book illustrate the importance of numerical methods in fluid mechanics. With research continually evolving in the field, there is no doubt that new techniques and tools will emerge to offer greater accuracy and speed in solving and analyzing even more fluid flow problems.
Download or read book Annual Research Briefs written by Center for Turbulence Research (U.S.) and published by . This book was released on 2007 with total page 428 pages. Available in PDF, EPUB and Kindle. Book excerpt:
