by National Aeronautics and Space Administration, For sale by the National Technical Information Service in [Washington, DC], [Springfield, Va .
Written in English
|Other titles||Wall layer eruptions in turbulent flows.|
|Statement||J. D. A. Walker.|
|Series||NASA technical memorandum -- 102362., ICOMP -- 89-26., ICOMP -- no. 89-26.|
|Contributions||United States. National Aeronautics and Space Administration.|
|The Physical Object|
Get this from a library! Wall-layer eruptions in turbulent flows. [J D A Walker; United States. National Aeronautics and Space Administration.]. Turbulent wall-bounded shear flows are common in engineering practice and, although such motions can be very complex, generic trends are exhibited over a wide range of Reynolds numbers. Turbulent flow near walls is common in a wide variety of engineering applications, including a spectrum of external flows encountered on aircraft and ship surfaces and the blades of gas turbines. In many situations, the external flow field is effectively irrotational and by: The asymptotic structure of the three-dimensional turbulent boundary layer near a plane of symmetry is considered in the limit of large Reynolds number. A selfconsistent two-layer structure is shown to exist wherein the streamwise velocity is brought to rest through an outer defect layer and an inner wall layer in a manner similar to that in.
Wall-layer streaks can be readily observed in any turbulent flow adjacent to the wall, and are now known to be a persistent and dominant feature of the near-. Turbulent flow fields near walls can be divided into an outer and an inner region e.g. (Panton, ). The inner region can be further divided into a wall layer and a log-law layer following the work of Prandtl and Millikan. The wall layer The process of turbulence production in the . In a similar titled IUTAM Symposium (Structure of Turbulence and Drag Reduction) was held in Washington. However, the progress made during the last thirteen years as weil as the much promising current research desired a second one this year. In Washington drag reduction by additives and byBrand: Springer-Verlag Berlin Heidelberg. This paper is a continuation of an earlier paper [P.E. Hancock, Velocity scales in the near-wall layer beneath reattaching turbulent separated and boundary layer flows, Eur. J. Mech. B Fluids 24 () –] in which it is proposed that each Reynolds stress has its own velocity by: 3.
Structure of Turbulence and Drag Reduction: IUTAM Symposium Zurich, Switzerland July , [Albert Gyr] -- In a similar titled IUTAM Symposium (Structure of Turbulence and Drag Reduction) was held in Washington. Wall layer eruptions in turbulent flows IUTAM Symposium Zurich, Switzerland July , \/span>\n. The present work studies, in detail, the unsteady wall-layer model of Walker et al. (, AIAA J., 27, – ) for the velocity profile in turbulent flows. Two new terms are included in the transcendental nonlinear system of equations that is used to determine the three main model by: 1. Law-of-the-wall (LOTW) scaling implies that at sufficiently high Reynolds numbers the mean velocity gradient ∂ U / ∂ z in the turbulent boundary layer should scale on u ∗ / z in the inertia-dominated surface layer, where u ∗ is the friction velocity and z is the distance from the surface. In , Mason and Thomson pointed out that large-eddy simulation (LES) of the atmospheric Cited by: Many turbulent flows of practical interest are bounded by a solid surface that acts as a source of shear; within this category the simplest possible case is that of a turbulent boundary layer on a flat plate. Because the present physical understanding of the under- lying processes responsible for the preservation of a turbulent boundary.