Development of a Near-Wall Reynolds-Stress Closure Based on the Ssg Model for the Pressure Strain
Development of a Near-Wall Reynolds-Stress Closure Based on the Ssg Model for the Pressure Strain

Author: National Aeronautics and Space Administration (NASA)

Publisher: Createspace Independent Publishing Platform

Published: 2018-07-17

Total Pages: 136

ISBN-13: 9781723025662

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In this research, a near-wall second-order closure based on the Speziable et al.(1991) or SSG model for the pressure-strain term is proposed. Unlike the LRR model, the SSG model is quasi-nonlinear and yields better results when applied to calculate rotating homogeneous turbulent flows. An asymptotic analysis near the wall is applied to both the exact and modeled, equations so that appropriate near-wall corrections to the SSG model and the modeled dissipation-rate equation can be derived to satisfy the physical wall boundary conditions as well as the asymptotic near-wall behavior of the exact equations. Two additional model constants are introduced and they are determined by calibrating against one set of near-wall channel flow data. Once determined, their values are found to remain constant irrespective of the type of flow examined. The resultant model is used to calculate simple turbulent flows, near separating turbulent flows, complex turbulent flows and compressible turbulent flows with a freestream Mach number as high as 10. In all the flow cases investigated, the calculated results are in good agreement with data. This new near-wall model is less ad hoc, physically and mathematically more sound and eliminates the empiricism introduced by Zhang. Therefore, it is quite general, as demonstrated by the good agreement achieved with measurements covering a wide range of Reynolds numbers and Mach numbers. So, R. M. C. and Aksoy, H. and Sommer, T. P. and Yuan, S. P. Unspecified Center BOUNDARY CONDITIONS; CHANNEL FLOW; MATHEMATICAL MODELS; PRESSURE GRADIENTS; REYNOLDS STRESS; WALL FLOW; ASYMPTOTIC PROPERTIES; BOUNDARY LAYERS; MACH NUMBER; ROTATION; SHEAR STRESS; TURBULENT FLOW...

Scientific and Technical Aerospace Reports
Scientific and Technical Aerospace Reports

Author:

Publisher:

Published: 1995

Total Pages: 700

ISBN-13:

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Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

Turbulent Flow
Turbulent Flow

Author: Peter S. Bernard

Publisher: John Wiley & Sons

Published: 2002-08-19

Total Pages: 516

ISBN-13: 9780471332190

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Provides unique coverage of the prediction and experimentation necessary for making predictions. * Covers computational fluid dynamics and its relationship to direct numerical simulation used throughout the industry. * Covers vortex methods developed to calculate and evaluate turbulent flows. * Includes chapters on the state-of-the-art applications of research such as control of turbulence.

Turbulent Fluid Flow
Turbulent Fluid Flow

Author: Peter S. Bernard

Publisher: John Wiley & Sons

Published: 2019-03-11

Total Pages: 356

ISBN-13: 1119106222

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A guide to the essential information needed to model and compute turbulent flows and interpret experiments and numerical simulations Turbulent Fluid Flow offers an authoritative resource to the theories and models encountered in the field of turbulent flow. In this book, the author – a noted expert on the subject – creates a complete picture of the essential information needed for engineers and scientists to carry out turbulent flow studies. This important guide puts the focus on the essential aspects of the subject – including modeling, simulation and the interpretation of experimental data - that fit into the basic needs of engineers that work with turbulent flows in technological design and innovation. Turbulent Fluid Flow offers the basic information that underpins the most recent models and techniques that are currently used to solve turbulent flow challenges. The book provides careful explanations, many supporting figures and detailed mathematical calculations that enable the reader to derive a clear understanding of turbulent fluid flow. This vital resource: Offers a clear explanation to the models and techniques currently used to solve turbulent flow problems Provides an up-to-date account of recent experimental and numerical studies probing the physics of canonical turbulent flows Gives a self-contained treatment of the essential topics in the field of turbulence Puts the focus on the connection between the subject matter and the goals of fluids engineering Comes with a detailed syllabus and a solutions manual containing MATLAB codes, available on a password-protected companion website Written for fluids engineers, physicists, applied mathematicians and graduate students in mechanical, aerospace and civil engineering, Turbulent Fluid Flow contains an authoritative resource to the information needed to interpret experiments and carry out turbulent flow studies.

A New Hypothesis on the Anisotropic Reynolds Stress Tensor for Turbulent Flows
A New Hypothesis on the Anisotropic Reynolds Stress Tensor for Turbulent Flows

Author: László Könözsy

Publisher: Springer

Published: 2019-02-26

Total Pages: 152

ISBN-13: 3030135438

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This book gives a mathematical insight--including intermediate derivation steps--into engineering physics and turbulence modeling related to an anisotropic modification to the Boussinesq hypothesis (deformation theory) coupled with the similarity theory of velocity fluctuations. Through mathematical derivations and their explanations, the reader will be able to understand new theoretical concepts quickly, including how to put a new hypothesis on the anisotropic Reynolds stress tensor into engineering practice. The anisotropic modification to the eddy viscosity hypothesis is in the center of research interest, however, the unification of the deformation theory and the anisotropic similarity theory of turbulent velocity fluctuations is still missing from the literature. This book brings a mathematically challenging subject closer to graduate students and researchers who are developing the next generation of anisotropic turbulence models. Indispensable for graduate students, researchers and scientists in fluid mechanics and mechanical engineering.