Download or read book Development and Validation of a One Equation Turbulence Model written by B. Aupoix and published by . This book was released on 1998 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Turbulence Modeling Validation Testing and Development written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-17 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: The primary objective of this work is to provide accurate numerical solutions for selected flow fields and to compare and evaluate the performance of selected turbulence models with experimental results. Four popular turbulence models have been tested and validated against experimental data often turbulent flows. The models are: (1) the two-equation k-epsilon model of Wilcox, (2) the two-equation k-epsilon model of Launder and Sharma, (3) the two-equation k-omega/k-epsilon SST model of Menter, and (4) the one-equation model of Spalart and Allmaras. The flows investigated are five free shear flows consisting of a mixing layer, a round jet, a plane jet, a plane wake, and a compressible mixing layer; and five boundary layer flows consisting of an incompressible flat plate, a Mach 5 adiabatic flat plate, a separated boundary layer, an axisymmetric shock-wave/boundary layer interaction, and an RAE 2822 transonic airfoil. The experimental data for these flows are well established and have been extensively used in model developments. The results are shown in the following four sections: Part A describes the equations of motion and boundary conditions; Part B describes the model equations, constants, parameters, boundary conditions, and numerical implementation; and Parts C and D describe the experimental data and the performance of the models in the free-shear flows and the boundary layer flows, respectively. Bardina, J. E. and Huang, P. G. and Coakley, T. J. Ames Research Center...
Download or read book Turbulence Modeling Validation Testing and Development written by and published by . This book was released on 1997 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development of One equation Transition turbulence Models written by J. R. Edwards and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Aerodynamics of Heavy Vehicles Trucks Buses and Trains written by Rose McCallen and published by Springer Science & Business Media. This book was released on 2004-09 with total page 590 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book includes the carefully edited contributions to the United Engineering Foundation Conference: The Aerodynamics of Heavy Vehicles: Trucks, Buses and Trains held in Monterey, California from December 2-6, 2002. This conference brought together 90 leading engineering researchers discussing the aerodynamic drag of heavy vehicles. The book topics include a comparison of computational fluid dynamics calculations using both steady and unsteady Reynolds-averaged Navier-Stokes, large-eddy simulation, and hybrid turbulence models and experimental data obtained from wind tunnel experiments. Advanced experimental techniques including three-dimensional particle image velocimetry are presented as well, along with their use in evaluating drag reduction devices.
Download or read book A Simple Two equation Turbulence Model for Transition sensitive CFD Simulations of Missile Nose cone Geometries written by Joseph Matthew Jones and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This study reports the development and validation of a modified two-equation eddy-viscosity turbulence model for computational fluid dynamics prediction of transitional and turbulent flows. The existing terms of the standard k-w model have been modified to include transitional flow effects, within the framework of Reynolds-averaged, eddy-viscosity turbulence modeling. The new model has been implemented into the commercially available flow solver FLUENT and the Mississippi State University SimCenter developed flow solver U2NCLE. Test cases included flow over a flat plate, a 2-D circular cylinder in a crossflow, a 3-D cylindrical body and three conical geometries, which represent the nose-cones of aerodynamic vehicles such as missiles. The results illustrate the ability of the model to yield reasonable predictions of transitional flow behavior using a simple modeling framework, including an appropriate response to freestream turbulence quantities, boundary-layer separation, and angle of attack.
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.
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.
Download or read book Critical Evaluation and Development of One equation Near wall Turbulence Models written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advances in Hybrid RANS LES Modelling written by Shia-Hui Peng and published by Springer. This book was released on 2008-02-26 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt: Turbulence modelling has long been, and will remain, one of the most important t- ics in turbulence research, challenging scientists and engineers in the academic world and in the industrial society. Over the past decade, Detached Eddy Simulation (DES) and other hybrid RANS-LES methods have received increasing attention from the turbulence-research community, as well as from industrial CFD engineers. Indeed, as an engineering modelling approach, hybrid RANS-LES methods have acquired a remarkable profile in modelling turbulent flows of industrial interest in relation to, for example, transportation, energy production and the environment. The advantage exploited with hybrid RANS-LES modelling approaches, being - tentially more computationally efficient than LES and more accurate than (unsteady) RANS, has motivated numerous research and development activities. These activities, together with industrial applications, have been further facilitated over the recent years by the rapid development of modern computing resources. As a European initiative, the EU project DESider (Detached Eddy Simulation for Industrial Aerodynamics, 2004-2007), has been one of the earliest and most systematic international R&D effort with its focus on development, improvement and applications of a variety of existing and new hybrid RANS-LES modelling approaches, as well as on related numerical issues. In association with the DESider project, two subsequent international symposia on hybrid RANS-LES methods have been arranged in Stockholm (Sweden, 2005) and in Corfu (Greece, 2007), respectively. The present book is a result of the Second Symposium on Hybrid RANS-LES Methods, held in Corfu, Greece, 17-18 June 2007.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development of a One equation Eddy Viscosity Turbulence Model for Application to Complex Turbulent Flows written by Timothy J. Wray and published by . This book was released on 2016 with total page 139 pages. Available in PDF, EPUB and Kindle. Book excerpt: Computational fluid dynamics (CFD) is routinely used in performance prediction and design of aircraft, turbomachinery, automobiles, and in many other industrial applications. Despite its wide range of use, deficiencies in its prediction accuracy still exist. One critical weakness is the accurate simulation of complex turbulent flows using the Reynolds-Averaged Navier-Stokes equations in conjunction with a turbulence model. The goal of this research has been to develop an eddy viscosity type turbulence model to increase the accuracy of flow simulations for mildly separated flows, flows with rotation and curvature effects, and flows with surface roughness. It is accomplished by developing a new zonal one-equation turbulence model which relies heavily on the flow physics; it is now known in the literature as the Wray-Agarwal one-equation turbulence model. The effectiveness of the new model is demonstrated by comparing its results with those obtained by the industry standard one-equation Spalart-Allmaras model and two-equation Shear-Stress-Transport k -- [omega] model and experimental data. Results for subsonic, transonic, and supersonic flows in and about complex geometries are presented. It is demonstrated that the Wray-Agarwal model can provide the industry and CFD researchers an accurate, efficient, and reliable turbulence model for the computation of a large class of complex turbulent flows.
Download or read book Development and Validation of Turbulence Models Through Experiment and Computation written by Torbjörn Sjögren and published by . This book was released on 1997 with total page 47 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book On the Validation of a Code and a Turbulence Model Appropriate to Circulation Control Airfoils written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-10-18 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: A computer code for calculating flow about a circulation control airfoil within a wind tunnel test section has been developed. This code is being validated for eventual use as an aid to design such airfoils. The concept of code validation being used is explained. The initial stages of the process have been accomplished. The present code has been applied to a low-subsonic, 2-D flow about a circulation control airfoil for which extensive data exist. Two basic turbulence models and variants thereof have been successfully introduced into the algorithm, the Baldwin-Lomax algebraic and the Jones-Launder two-equation models of turbulence. The variants include adding a history of the jet development for the algebraic model and adding streamwise curvature effects for both models. Numerical difficulties and difficulties in the validation process are discussed. Turbulence model and code improvements to proceed with the validation process are also discussed. Viegas, J. R. and Rubesin, M. W. and Maccormack, R. W. Ames Research Center RTOP 505-60-11
Download or read book Modeling Complex Turbulent Flows written by Manuel D. Salas and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 385 pages. Available in PDF, EPUB and Kindle. Book excerpt: Turbulence modeling both addresses a fundamental problem in physics, 'the last great unsolved problem of classical physics,' and has far-reaching importance in the solution of difficult practical problems from aeronautical engineering to dynamic meteorology. However, the growth of supercom puter facilities has recently caused an apparent shift in the focus of tur bulence research from modeling to direct numerical simulation (DNS) and large eddy simulation (LES). This shift in emphasis comes at a time when claims are being made in the world around us that scientific analysis itself will shortly be transformed or replaced by a more powerful 'paradigm' based on massive computations and sophisticated visualization. Although this viewpoint has not lacked ar ticulate and influential advocates, these claims can at best only be judged premature. After all, as one computational researcher lamented, 'the com puter only does what I tell it to do, and not what I want it to do. ' In turbulence research, the initial speculation that computational meth ods would replace not only model-based computations but even experimen tal measurements, have not come close to fulfillment. It is becoming clear that computational methods and model development are equal partners in turbulence research: DNS and LES remain valuable tools for suggesting and validating models, while turbulence models continue to be the preferred tool for practical computations. We believed that a symposium which would reaffirm the practical and scientific importance of turbulence modeling was both necessary and timely.
Download or read book A Collection of Technical Papers written by American Institute of Aeronautics and Astronautics and published by AIAA (American Institute of Aeronautics & Astronautics). This book was released on 1997 with total page 646 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains the proceedings of the 13th AIAA Computational Fluid Dynamics Conference. It addresses numerical procedures for the solution of fluid dynamics and interdisciplinary problems. Technical sessions of the conference focus on design optimization, solution adaptive techniques, convergence acceleration methods, high-resolution schemes, parallel computing as well as improved algorithms for the solution of viscous, inviscid, and multi-component flow applications. The programme also includes a panel discussion addressing the evoluting roles of government, industry and academia in future CFD developments.
Download or read book Turbulence Modeling for CFD CD ROM written by David C. Wilcox and published by . This book was released on 2006 with total page 522 pages. Available in PDF, EPUB and Kindle. Book excerpt:
