Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 34
Book Description
Numerical Simulation of Boundary Layers. Part 3: Turbulence and Relaminarization in Sink Flows
Author: Scientific and Technical Aerospace Reports
Author: Three-dimensional Turbulent Boundary Layers
Author: O. SendstadPublisher:
ISBN:
Category : Simulation methods
Languages : en
Pages : 130
Book Description
Numerical Simulation of Unsteady Three-Dimensional Turbulent Structures in Boundary Layer Flows
Author: Nan S. LuiPublisher:
ISBN:
Category :
Languages : en
Pages : 45
Book Description
The capabilities for numerical simulations of the dynamical effects of the underlying structures occurring in turbulent boundary layers have been developed. A mathematically operational model of hairpin vortex, which closely resembles the experimentally observed underlying structure of wall turbulence, has been constructed and the evolution of this incipient hairpin vortex as well as the distortion of a background laminar boundary layer has been successfully simulated. The height of the incipient hairpin vortex is about 1/5 fo the local boundary layer thickness. The calculated results not only exhibit most of the prominent features associated with turbulent spots and turbulent boundary layer flows, but also reveal dynamic processes which have been very difficult to observe in experimental studies, notably, the formation and intensification of another counter rotating hairpin vortex immediately upstream of the incipient hairpin vortex. Keywords: Navier-Stokes equations; Coherent wall structure.
The Origin of Turbulence in Near-Wall Flows
Author: A.V. BoikoPublisher: Springer Science & Business Media
ISBN: 9783540421818
Category : Science
Languages : en
Pages : 286
Book Description
This book presents a comprehensive survey of the origin of turbulence in near-wall shear layer flows. Instead of going too far into details modern approaches to the problem are discussed in a conceptual treatment. The transition from laminar to turbulent flows in shear layers is described including the generation of flow perturbations, their amplification and development, the breakdown of the initial laminar state, and transformation to a turbulent regime. This book also presents new approaches to boundary-layer transitions with strong external-flow perturbations and to the prediction and control of the presented near-wall transitions to turbulence. This book is addressed to researchers, lecturers and students in engineering, physics and mathematics.
Laminar-Turbulent Transition
Author: Ryoji KobayashiPublisher: Springer Science & Business Media
ISBN: 3642797652
Category : Technology & Engineering
Languages : en
Pages : 541
Book Description
The International Union of Theoretical and Applied Mechanics (IUTAM) decided in 1992 to sponsor the fourth Symposium on Laminar-Turbulent Transition, Sendai/Japan, 1994. The objectives of the present Symposium were to deepen the fundamental knowledge of stability and laminar turbulent transition in three-dimensional and compressible flows and to contribute to recent developing technologies in the field. This Symposium followed the three previous IUTAM-Symposia (Stuttgart 1979, Novosibirsk 1984 and Toulouse 1989). The Scientific Committee selected two keynote lectures and 62 technical papers. The Symposium was held on the 5th to 9th of September, 1994, at the Sendai International Center in Sendai. The participants were 82 scientists from 10 countries. The keynote lectures have critically reviewed recent development of researches concerning the laminar-to-turbulent transition phenomena from the fundamental and the application aspects. Many papers presented were concerned about the detailed mechanism of the boundary layer transition (receptivity, secondary instability, turbulent spot and bypass transition). Particular emphasis was further placed on the transition of three-dimensional boundary layers on rotation systems and on swept wings. Attention was also given to compressible hypersonic flows.
Applied Mechanics Reviews
Author: Monthly Catalog of United States Government Publications
Author: Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1112
Book Description
Government Reports Annual Index
Author: Publisher:
ISBN:
Category : Research
Languages : en
Pages : 1428
Book Description
Sections 1-2. Keyword Index.--Section 3. Personal author index.--Section 4. Corporate author index.-- Section 5. Contract/grant number index, NTIS order/report number index 1-E.--Section 6. NTIS order/report number index F-Z.
Numerical Study of a Three-Dimensional Turbulent Boundary Layer
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
The effects of transverse strain on an initially two-dimensional turbulent boundary layer are studied in a direct numerical simulation of a planar channel flow with impulsively started transverse pressure gradient. Consistent with experiments in three-dimensional boundary layers, the simulation shows a decrease in the Reynolds shear stress with increasing transverse strain. Also, the directions of the Reynolds shear stress vector and the mean velocity gradient vector were found to differ. In addition, the simulation shows a drop in the turbulent kinetic energy. Terms in the Reynolds stress transport equations were computed. The balances indicate that the decrease in turbulent kinetic energy is a result of a decrease in turbulence production, along with an increase in turbulent dissipation. The effects of the transverse pressure gradient on the instantaneous flow structures were investigated.