Experimental Study of a Three-dimensional Shear-driven Turbulent Boundary Layer with Streamwise Adverse Pressure Gradient PDF Download

Author: David Michael Driver
Publisher:
ISBN:
Category : Boundary layer
Languages : en
Pages : 268

View

Book Description

Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781723575372
Category :
Languages : en
Pages : 266

View

Book Description
The effects of a strong adverse pressure gradient on a three-dimensional turbulent boundary layer are studied in an axisymmetric spinning cylinder geometry. Velocity measurements made with a three-component laser Doppler velocimeter include all three mean flow components, all six Reynolds stress components, and all ten triple-product correlations. Reynolds stress diminishes as the flow becomes three-dimensional. Lower levels of shear stress were seen to persist under adverse pressure gradient conditions. This low level of stress was seen to roughly correlate with the magnitude of cross-flow (relative to free stream flow) for this experiment as well as most of the other experiments in the literature. Variations in pressure gradient do not appear to alter this correlation. For this reason, it is hypothesized that a three-dimensional boundary layer is more prone to separate than a two-dimensional boundary layer, although it could not be directly shown here. None of the computations performed with either a Prandtl mixing length, k-epsilon, or a Launder-Reece-Rodi full Reynolds-stress model were able to predict the reduction in Reynolds stress. Driver, David M. and Johnston, James P. Ames Research Center NASA-TM-102211, A-89104, NAS 1.15:102211, NONP-NASA-SUPPL-CD-ROM-93-159790 RTOP 505-60-11...

Author: Stanford University. Thermosciences Division
Publisher:
ISBN:
Category : Turbulent boundary layer
Languages : en
Pages : 390

View

Book Description

Author: O. Sendstad
Publisher:
ISBN:
Category : Simulation methods
Languages : en
Pages : 130

View

Book Description

Author: Jean Piquet
Publisher: Springer Science & Business Media
ISBN: 3662035596
Category : Technology & Engineering
Languages : en
Pages : 767

View

Book Description
obtained are still severely limited to low Reynolds numbers (about only one decade better than direct numerical simulations), and the interpretation of such calculations for complex, curved geometries is still unclear. It is evident that a lot of work (and a very significant increase in available computing power) is required before such methods can be adopted in daily's engineering practice. I hope to l"Cport on all these topics in a near future. The book is divided into six chapters, each· chapter in subchapters, sections and subsections. The first part is introduced by Chapter 1 which summarizes the equations of fluid mechanies, it is developed in C~apters 2 to 4 devoted to the construction of turbulence models. What has been called "engineering methods" is considered in Chapter 2 where the Reynolds averaged equations al"C established and the closure problem studied (§1-3). A first detailed study of homogeneous turbulent flows follows (§4). It includes a review of available experimental data and their modeling. The eddy viscosity concept is analyzed in §5 with the l"Csulting ~alar-transport equation models such as the famous K-e model. Reynolds stl"Css models (Chapter 4) require a preliminary consideration of two-point turbulence concepts which are developed in Chapter 3 devoted to homogeneous turbulence. We review the two-point moments of velocity fields and their spectral transforms (§ 1), their general dynamics (§2) with the particular case of homogeneous, isotropie turbulence (§3) whel"C the so-called Kolmogorov's assumptions are discussed at length.

Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 704

View

Book Description

Author: Franz Durst
Publisher: Springer Science & Business Media
ISBN: 3642776744
Category : Science
Languages : en
Pages : 419

View

Book Description
This volume contains a selection of the papers presented at the Eighth Symposium on Turbulent Shear Flows held at the Technical University of Munich, 9-11 September 1991. The first of these biennial international symposia was held at the Pennsylvania State Uni versity, USA, in 1977; subsequent symposia have been held at Imperial College, London, England; the University of California, Davis, USA; the University of Karlsruhe, Ger many; Cornell University, Ithaca, USA; the Paul Sabatier University, Toulouse, France; and Stanford University, California, USA. The purpose of this series of symposia is to provide a forum for the presentation and discussion of new developments in the field of turbulence, especially as related to shear flows of importance in engineering and geo physics. From the 330 extended abstracts submitted for this symposium, 145 papers were presented orally and 60 as posters. Out of these, we have selected twenty-four papers for inclusion in this volume, each of which has been revised and extended in accordance with the editors' recommendations. The following four theme areas were selected after consideration of the quality of the contributions, the importance of the area, and the selection made in earlier volumes: - wall flows, - separated flows, - compressibility effects, - buoyancy, rotation, and curvature effects. As in the past, each section corresponding to the above areas begins with an introduction by an authority in the field that places the individual contributions in context with one another and with related research.

Author: J. P. Johnston
Publisher:
ISBN:
Category : Boundary layer
Languages : en
Pages : 62

View

Book Description
The various methods for measurement of the six components of the turbulence stress tensor are reviewed, and some of the data on the turbulent shear stress vector are presented to demonstrate the validity of current ideas for.

Author: United States. Superintendent of Documents
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1072

View

Book Description
February issue includes Appendix entitled Directory of United States Government periodicals and subscription publications; September issue includes List of depository libraries; June and December issues include semiannual index

Author:
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1786

View

Book Description