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Book Boundary layer Transition Prediction for Reynolds averaged Navier Stokes Methods

Download or read book Boundary layer Transition Prediction for Reynolds averaged Navier Stokes Methods written by Edward Anthony Mayda and published by . This book was released on 2007 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book An Adaptive High Order Reynolds averaged Navier Stokes Solver with Transition Prediction

Download or read book An Adaptive High Order Reynolds averaged Navier Stokes Solver with Transition Prediction written by David Moro-Ludeña and published by . This book was released on 2015 with total page 239 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of simulation techniques in applied aerodynamics has increased dramatically in the last three decades fostered by the growth in computational power. However, the state of the art discretization in industrial solvers remains nominally second order accurate, which makes them unfeasible to resolve multi-scale phenomena such as turbulence or acoustics, and limits their efficiency in terms of the error per degree of freedom. In recent years, the CFD community has put significant effort into the development of high order methods for fluid dynamics, with the goal of overcoming these barriers. This dissertation focuses on the application of high order hybridizable discontinuous Galerkin schemes to solve the equations that govern compressible turbulent flows. In particular, this thesis describes a novel methodology to adapt the boundary layer mesh to the solution "on the fly", based on a measure of the boundary layer thickness that drives the position of the nodes in the mesh, without changing its topology. The proposed algorithm produces accurate solutions with a reduced number of degrees of freedom, by leveraging the combination of mesh adaptivity with the high order of convergence of the discretization. In addition, the active tracking of the boundary layer reduces the nonlinear stiffness and improves the robustness of the numerical solution. A new shock capturing technique based on the addition of artificial viscosity is developed to handle shocks. The model is driven by a non-dimensional form of the divergence of the velocity, designed so that sub-cell shock resolution is achieved when a high order discretization is used, independently of the element size. The approach is extended to include the effect of transition to turbulence using an envelope eN method. This takes advantage of the structure of the mesh and requires the solution of a surface PDE for the transition criterion, which is discretized using a novel surface hybridizable discontinuous Galerkin scheme. The resulting method can simulate transition to turbulence in attached and separated flows, and can also accommodate long-scale unsteadiness in which the transition location evolves in time.

Book Prediction of Transitional Boundary Layers and Fully Turbulent Free Shear Flows  Using Reynolds Averaged Navier Stokes Models

Download or read book Prediction of Transitional Boundary Layers and Fully Turbulent Free Shear Flows Using Reynolds Averaged Navier Stokes Models written by Maurin Lopez and published by . This book was released on 2014 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the biggest unsolved problems of modern physics is the turbulence phenomena in fluid flow. The appearance of turbulence in a flow system is regularly determined by velocity and length scales of the system. If those scales are small the motion of the fluid is laminar, but at larger scales, disturbances appear and grow, leading the flow field to transition to a fully turbulent state. The prediction of transitional flow is critical for many complex fluid flow applications, such as aeronautical, aerospace, biomedical, automotive, chemical processing, heating and cooling systems, and meteorology. For example, in some cases the flow may remain laminar throughout a significant portion of a given domain, and fully turbulent simulations may produce results that can lead to inaccurate conclusions or inefficient design, due to an inability to resolve the details of the transition process. This work aims to develop, implement, and test a new model concept for the prediction of transitional flows using a linear eddy-viscosity RANS approach. The effects of transition are included through one additional transport equation for u2 as an alternative to the Laminar Kinetic Energy (LKE) framework. Here u2 is interpreted as the energy of fully turbulent, three-dimensional velocity fluctuations. This dissertation presents two new single-point, physics-based turbulence models based on the transitional methodology mentioned above. The first one uses an existing transitional model as a baseline which is modified to accurately capture the physics of fully turbulent free shear flows. The model formulation was tested over several boundary layer and free shear flow test cases. The simulations show accurate results, qualitatively equal to the baseline model on transitional boundary layer test cases, and substantially improved over the baseline model for free shear flows. The second model uses the SST k-w fully turbulent model and again the effects of transition are included through one additional transport equation for u2. An initial version of the model is presented here. Simplicity of the formulation and ease of extension to other baseline models are two potential advantages of the new method.

Book Boundary Layer Flows

    Book Details:
  • Author : Vallampati Ramachandra Prasad
  • Publisher : BoD – Books on Demand
  • Release : 2020-01-22
  • ISBN : 1839681853
  • Pages : 236 pages

Download or read book Boundary Layer Flows written by Vallampati Ramachandra Prasad and published by BoD – Books on Demand. This book was released on 2020-01-22 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by experts in the field, this book, "Boundary Layer Flows - Theory, Applications, and Numerical Methods" provides readers with the opportunity to explore its theoretical and experimental studies and their importance to the nonlinear theory of boundary layer flows, the theory of heat and mass transfer, and the dynamics of fluid. With the theory's importance for a wide variety of applications, applied mathematicians, scientists, and engineers - especially those in fluid dynamics - along with engineers of aeronautics, will undoubtedly welcome this authoritative, up-to-date book.

Book Shock Wave Boundary Layer Interactions

Download or read book Shock Wave Boundary Layer Interactions written by Holger Babinsky and published by Cambridge University Press. This book was released on 2011-09-12 with total page 481 pages. Available in PDF, EPUB and Kindle. Book excerpt: Shock wave-boundary-layer interaction (SBLI) is a fundamental phenomenon in gas dynamics that is observed in many practical situations, ranging from transonic aircraft wings to hypersonic vehicles and engines. SBLIs have the potential to pose serious problems in a flowfield; hence they often prove to be a critical - or even design limiting - issue for many aerospace applications. This is the first book devoted solely to a comprehensive, state-of-the-art explanation of this phenomenon. It includes a description of the basic fluid mechanics of SBLIs plus contributions from leading international experts who share their insight into their physics and the impact they have in practical flow situations. This book is for practitioners and graduate students in aerodynamics who wish to familiarize themselves with all aspects of SBLI flows. It is a valuable resource for specialists because it compiles experimental, computational and theoretical knowledge in one place.

Book Engineering Turbulence Modelling and Experiments   4

Download or read book Engineering Turbulence Modelling and Experiments 4 written by D. Laurence and published by Elsevier. This book was released on 1999-04-14 with total page 975 pages. Available in PDF, EPUB and Kindle. Book excerpt: These proceedings contain the papers presented at the 4th International Symposium on Engineering Turbulence Modelling and Measurements held at Ajaccio, Corsica, France from 24-26 May 1999. It follows three previous conferences on the topic of engineering turbulence modelling and measurements. The purpose of this series of symposia is to provide a forum for presenting and discussing new developments in the area of turbulence modelling and measurements, with particular emphasis on engineering-related problems. Turbulence is still one of the key issues in tackling engineering flow problems. As powerful computers and accurate numerical methods are now available for solving the flow equations, and since engineering applications nearly always involve turbulence effects, the reliability of CFD analysis depends more and more on the performance of the turbulence models. Successful simulation of turbulence requires the understanding of the complex physical phenomena involved and suitable models for describing the turbulent momentum, heat and mass transfer. For the understanding of turbulence phenomena, experiments are indispensable, but they are equally important for providing data for the development and testing of turbulence models and hence for CFD software validation.

Book Elements of Transitional Boundary Layer Flowlements

Download or read book Elements of Transitional Boundary Layer Flowlements written by Robert Edward Mayle and published by Logos Verlag Berlin GmbH. This book was released on 2018 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt: Second Enhanced Edition Suitable for advanced-level courses or an independent study in fluid mechanics, this text by an expert in the field provides the basic aspects of laminar-to-turbulent flow transition in boundary layers. Logically organized into three major parts, the book covers pre- and post-transitional flow, transitional flow, and several advanced topics in periodically disturbed transitional flow. Some of the subjects covered within the book include high-frequency unsteady laminar flow, turbulent flow, natural transition, bypass transition, turbulent spot theory, turbulent spot kinematics and production, correlations for the onset and rate of transition, global and conditional averaging, transitional flow models, wakeinduced transition, multimode transition, and separated-flow transition. Containing some 202 figures (all drawn by the author), 28 tables, 12 appendices, a supplement on tensors, and an extensive bibliography, the 415 page book provides a wealth of data and information about the subject.

Book New Results in Numerical and Experimental Fluid Mechanics III

Download or read book New Results in Numerical and Experimental Fluid Mechanics III written by Siegfried Wagner and published by Springer Science & Business Media. This book was released on 2002-02-26 with total page 458 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains the papers of a German symposium dealing with research and project work in numerical and experimental aerodynamics and fluidmechanics for aerospace and other applications. It gives a broad overview over the ongoing work in this field in Germany.

Book An Introduction to Flapping Wing Aerodynamics

Download or read book An Introduction to Flapping Wing Aerodynamics written by Wei Shyy and published by Cambridge University Press. This book was released on 2013-08-19 with total page 321 pages. Available in PDF, EPUB and Kindle. Book excerpt: For anyone interested in the aerodynamics, structural dynamics and flight dynamics of small birds, bats, insects and air vehicles (MAVs).

Book Turbulence and Transition Modelling

Download or read book Turbulence and Transition Modelling written by M. Hallbäck and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 379 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this book is to give, within a single volume, an introduction to the fields of turbulence modelling and transition-to-turbulence prediction, and to provide the physical background for today's modelling approaches in these problem areas as well as giving a flavour of advanced use of prediction methods. Turbulence modelling approaches, ranging from single-point models based on the eddy-viscosity concept and the Reynolds stress transport equations (Chapters 3,4,5), to large-eddy simulation (LES) techniques (Ch. 7), are covered. The foundations of hydrodynamical stability and transition are presented (Ch. 2) along with transition prediction methods based on single-point closures (Ch. 6), LES techniques (Ch. 7) and the parabolized stability equations (Ch. 8). The book addresses engineers and researchers, in industry or academia, who are entering into the fields of turbulence or transition modelling research or need to apply turbulence or transition prediction methods in their work.

Book Modeling and Computation of Boundary Layer Flows

Download or read book Modeling and Computation of Boundary Layer Flows written by Tuncer Cebeci and published by Springer. This book was released on 2009-09-02 with total page 502 pages. Available in PDF, EPUB and Kindle. Book excerpt: This second edition of the book, Modeling and Computation of Boundary-Layer Flows^ extends the topic to include compressible flows. This implies the inclusion of the energy equation and non-constant fluid properties in the continuity and momentum equations. The necessary additions are included in new chapters, leaving the first nine chapters to serve as an introduction to incompressible flows and, therefore, as a platform for the extension. This part of the book can be used for a one semester course as described below. Improvements to the incompressible flows portion of the book include the removal of listings of computer programs and their description, and their incor poration in two CD-ROMs. A listing of the topics incorporated in the CD-ROM is provided before the index. In Chapter 7 there is a more extended discussion of initial conditions for three-dimensional flows, application of the characteristic box to a model problem and discussion of flow separation in three-dimensional laminar flows. There are also changes to Chapter 8, which now includes new sections on Tollmien-Schlichting and cross-flow instabilities and on the predic tion of transition with parabolised stability equations, and Chapter 9 provides a description of the rational behind interactive boundary-layer procedures.

Book Scientific and Technical Aerospace Reports

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book MEGAFLOW   Numerical Flow Simulation for Aircraft Design

Download or read book MEGAFLOW Numerical Flow Simulation for Aircraft Design written by Norbert Kroll and published by Springer Science & Business Media. This book was released on 2006-10-02 with total page 311 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aerospace industry increasingly relies on advanced numerical simulation tools in the early design phase. This volume provides the results of a German initiative which combines many of the CFD development activities from the German Aerospace Center (DLR), universities, and aircraft industry. Numerical algorithms for structured and hybrid Navier-Stokes solvers are presented in detail. The capabilities of the software for complex industrial applications are demonstrated.

Book Charts for Estimating Boundary layer Transition on Flat Plates

Download or read book Charts for Estimating Boundary layer Transition on Flat Plates written by Edward J. Hopkins and published by . This book was released on 1970 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: