Author: Joseph Charles KlewickiPublisher:
ISBN:
Category : Boundary layer
Languages : en
Pages : 652
Book Description
On the Interactions Between the Inner and Outer Region Motions in Turbulent Boundary Layers
Author: Joseph Charles KlewickiPublisher:
ISBN:
Category : Boundary layer
Languages : en
Pages : 652
Book Description
A Multiple-view Visual Study of the Inner/outer Region Interactions of Coherent Motions in a Turbulent Boundary Layer
Author: Kue PanOn the Application and Interpretation of Coherent Motion Detectors
Author: Charles Paul GendrichPublisher:
ISBN:
Category : Turbulence
Languages : en
Pages : 604
Book Description
Coherent motions are understood to play an important role in enhancing the momentum transport of turbulent wall bounded shear flows, but determining whether or not a coherent motion is present in a given volume of space at a particular time is still a difficult task. Although most detection schemes were developed for use within a specific region above the wall, most are ultimately used throughout the entire boundary layer. Three different probe based algorithms and three different visual detection schemes are applied to combined flow visualization and spanwise vorticity probe data taken in the near wall region and at y/delta of 0.8. Several new performance parameters have been developed, and they are calculated along with most of the commonly used evaluation parameters as functions of detection threshold and Reynolds number or y+. The one to one correspondence between probe based detections and visual detections is also evaluated using two parameters already in common use and a new parameter, P(T, t), which is based on the number of event overlaps as a function of time during an event inner, outer, and mixed variables are used whenever appropriate to scale all results, but only two Reynolds number independent curves are found which describe the outer region response of any detection algorithm as a function of threshold.
Turbulent Boundary Layer Inner-Outer Interactions
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 190
Book Description
A summary of work performed to study the interactions between the inner and outer regions of a turbulent boundary layer is presented. The interactions were studied by observing the response of the boundary layer to different perturbations. The inner region was modified by adding surface roughness, and the outer region suppressed using LEBU's. Velocity measurements were made with a three component LDV, a scanning LDV, and an X-type hot-film probe. The scanning LDV was developed to obtain continuous time history measurements of instantaneous velocity profiles down to y+ = 10. Details of the structure of bursts, sweeps, and shear layers over smooth and rough walls were determined using conditional sampling with simultaneous measurements from a detector probe and a mapping probe. This allowed the mapping of the complete three-dimensional structure of the three-component velocity field for these structures. Both single point detection, using quadrant and VITA techniques, and a unique spatially coherent structure detection technique were used. The spatial detection technique developed in this project takes advantage of the two- dimensional velocity field information obtained from the scanning LDV. Scanning laser doppler velocimeter, Burst, Sweep, Shear layer large scale structure.
Turbulent Flows
Author: Jean PiquetPublisher: Springer Science & Business Media
ISBN: 3662035596
Category : Technology & Engineering
Languages : en
Pages : 767
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.
Ten Chapters in Turbulence
Author: Peter A. DavidsonPublisher: Cambridge University Press
ISBN: 0521769442
Category : Science
Languages : en
Pages : 450
Book Description
Leading experts summarize our current understanding of the fundamental nature of turbulence, covering a wide range of topics.
A Study of Intermediate Scale Motions in the Outer Region of Turbulent Boundary Layers
Author: David Bruce SignorPublisher:
ISBN:
Category : Fluid dynamics
Languages : en
Pages : 418
Book Description
The Ocean Surface
Author: Y. TobaPublisher: Springer Science & Business Media
ISBN: 940157717X
Category : Science
Languages : en
Pages : 581
Book Description
Experiments on the Velocity Characteristics of "bursts" and on the Interactions Between the Inner and Outer Regions of a Turbulent Boundary Layer
Author: G. R. OffenPublisher:
ISBN:
Category : Boundary layer
Languages : en
Pages : 278
Book Description
Author: