Author: Tsan-Hsing ShihPublisher:
ISBN:
Category : Turbulence
Languages : en
Pages : 16
Book Description
Remarks on Turbulent Constitutive Relations
Author: Tsan-Hsing ShihPublisher:
ISBN:
Category : Turbulence
Languages : en
Pages : 16
Book Description
Remarks on Turbulent Constitutive Relations
Author: Tsan-Hsing ShihPublisher:
ISBN:
Category : Turbulence
Languages : en
Pages : 16
Book Description
NASA Technical Memorandum
Author: Transition, Turbulence and Combustion Modelling
Author: A. HanifiPublisher: Springer Science & Business Media
ISBN: 9401145156
Category : Science
Languages : en
Pages : 540
Book Description
This single-volume work gives an introduction to the fields of transition, turbulence, and combustion modeling of compressible flows and provides the physical background for today’s modeling approaches in these fields. It presents basic equations and discusses fundamental aspects of hydrodynamical instability.
A Realizable Reynolds Stress Algebraic Equation Model
Author: Tsan-Hsing ShihPublisher:
ISBN:
Category :
Languages : en
Pages : 42
Book Description
The invariance theory in continuum mechanics is applied to analyze Reynolds stresses in high Reynolds number turbulent flows. The analysis leads to a turbulent constitutive relation that relates the Reynolds stresses to the mean velocity gradients in a more general form in which the classical isotropic eddy viscosity model is just the linear approximation of the general form. On the basis of realizability analysis, a set of model coefficients are obtained which are functions of the time scale ratios of the turbulence to the mean strain rate and the mean rotation rate. The coefficients will ensure the positivity of each component of the mean rotation rate. These coefficients will ensure the positivity of each component of the turbulent kinetic energy - realizability that most existing turbulence models fail to satisfy. Separated flows over backward-facing step configurations are taken as applications. The calculations are performed with a conservative finite-volume method. Grid-independent and numerical diffusion-free solutions are obtained by using differencing schemes of second-order accuracy on sufficiently fine grids. The calculated results are compared in detail with the experimental data for both mean and turbulent quantities. The comparison shows that the present proposal significantly improves the predictive capability of K-epsilon based two equation models. In addition, the proposed model is able to simulate rotational homogeneous shear flows with large rotation rates which all conventional eddy viscosity models fail to simulate.
Scientific and Technical Aerospace Reports
Author: Toward a Turbulence Constitutive Relation for Rotating Flows
Author: Lecture Notes On Turbulence
Author: Jackson R HerringPublisher: World Scientific
ISBN: 9814520225
Category : Science
Languages : en
Pages : 385
Book Description
This book is a formal presentation of lectures given at the 1987 Summer School on Turbulence, held at the National Center for Atmospheric Research under the auspices of the Geophysical Turbulence Program. The lectures present in detail certain of the more challenging and interesting current turbulence research problems in engineering, meteorology, plasma physics, and mathematics. The lecturers-Uriel Frisch (Mathematics), Douglas Lilly (Meteorology), David Montgomery (Plasma Physics), and Hendrik Tennekes (Engineering) — are distinguished for both their research contributions and their abilities to communicate these to students with enthusiasm. This book is distinguished by its simultaneous focus on the fundamentals of turbulent flows (in neutral and ionized fluids) and on a presentation of current research tools and topics in these fields.
Engineering Turbulence Modelling and Experiments - 4
Author: D. LaurencePublisher: Elsevier
ISBN: 0080530982
Category : Science
Languages : en
Pages : 975
Book Description
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.
Author: J. R. Ristorcelli