Results 221 to 230 of about 584,538 (262)

Detection of second-order structure in optical flow fields

Journal of the Optical Society of America A, 1997
We investigate how well the direction of the expansion gradient and the direction of a spatial step in expansion can be extracted from a complex optical flow field. The expansion gradient is an invariant of the second-order structure under rotations of the image plane.
Te Pas, S.F., Kappers, A.M.L., Koenderink, J.J.   +2 more
openaire   +3 more sources

The structure of the vorticity field in homogeneous turbulent flows

Journal of Fluid Mechanics, 1987
The structure of the vorticity fields in homogeneous turbulent shear flow and various irrotational straining flows is examined using results from direct numerical simulations of the unsteady, incompressible Navier-Stokes equations with up to 128 × 128 × 128 grid points.
Michael M. Rogers, Parviz Moin
openaire   +1 more source

Organized structures in a reattaching separated flow field

Journal of Fluid Mechanics, 1984
Spanwise structures in a two-dimensional reattaching separated flow were studied using multisensor hot-wire anemometry techniques. The results of these measurements strongly support the existence and importance of large-scale vortices in both the separated and reattached regions of this flow.
T. R. Troutt, B. Scheelke, T. R. Norman
openaire   +1 more source

The structure of flow field at Yokogan-sone seamount

Oceans '04 MTS/IEEE Techno-Ocean '04 (IEEE Cat. No.04CH37600), 2005
The structure of flow field around a tall seamount, called Yokogan-sone, which is located to the southwest of the Nansei Islands in the East China Sea was investigated with a combination of observations and a numerical model simulation. The flow field around the seamount was preliminarily measured using an acoustic Doppler current profiler (ADCP) in ...
M. Oikawa, Y. Kyozuka, N. Yamawaki, H. Yoshimura, Y. Morii, A. Murao   +5 more
openaire   +1 more source

Structural Stability in Evolving Flow Fields

1979
The changing topology of an evolving flow field can be studied by mapping it into velocity space and observing the singularities. In two dimensions the structurally stable singularities are folds, which are lines, and cusps, which are isolated points on the folds [2].
openaire   +1 more source

Structure of the stretching field in chaotic cavity flows

AIChE Journal, 1994
AbstractStretching of material elements in time‐periodic cavity flows is investigated numerically. The spatial structure of the stretching field is determined not only by nonchaotic islands and by unstable manifolds of hyperbolic periodic points, but also by singularities of the flow field at the cavity corners. For the short time scales interesting to
M. Liu, R. L. Peskin, F. J. Muzzio, C. W. Leong   +3 more
openaire   +1 more source

Observations of the near-field structures of the glottal flow

The Journal of the Acoustical Society of America, 2005
The three-dimensional glottal jet was measured downstream from a self-oscillating physical model of the vocal folds using several techniques, including grid-based hotwire anemometry, high-speed flow visualization, and particle image velocimetry. Coherent flow structures were extracted from the spatio-temporal data using principal component analysis ...
Juergen Neubauer, Zhaoyan Zhang, David Berry   +2 more
openaire   +1 more source

Structure of self-field accelerated plasma flows

Journal of Propulsion and Power, 1991
An analysis is presented of self-field accelerated quasi-one-dimensional plasma flows with zero axial current. When magnetic convection dominates over magnetic diffusion (large magnetic Reynolds number Rm\ inlet and exit current concentration layers occur, which are analyzed by asymptotic methods to zeroth order in l/Rm.
openaire   +1 more source

Study on the flow structure around a flat plate in a stagnation flow field

Journal of Fluid Mechanics, 1990
Numerical solutions have been obtained for steady viscous flow past a finite flat plate attached normally to an infinite wall at Reynolds numbers Re up to 2800. Separately, Levi-Civita's method has been used to obtain the flow solution based on the free-streamline theory.
Yong Kweon Suh, Ching Shi Liu
openaire   +1 more source

Ball-like structures of the Beltrami flow field

ZAMM, 2005
Summary: We derive stationary Beltrami flow fields based on the analogy borrowed from the free Maxwell equations in vacuum. The stationary Beltrami field we obtained is helical and/or ball-like once it is represented in a suitable frame of reference. Our solutions also illustrate the formation of a ball-like pattern and the possible splitting (into two)
openaire   +2 more sources