Results 41 to 50 of about 437,461 (138)

Data-driven transient lift attenuation for extreme vortex gust–airfoil interactions [PDF]

Journal of Fluid Mechanics
We present a data-driven feedforward control to attenuate large transient lift experienced by an airfoil disturbed by an extreme level of discrete vortex gust.
Kai Fukami, Hiroya Nakao, Kunihiko Taira
semanticscholar   +1 more source

Visualizing the geometry of state space in plane Couette flow [PDF]

, 2007
Motivated by recent experimental and numerical studies of coherent structures in wall-bounded shear flows, we initiate a systematic exploration of the hierarchy of unstable invariant solutions of the Navier-Stokes equations. We construct a dynamical, 10^5-dimensional state-space representation of plane Couette flow at Re = 400 in a small, periodic cell
arxiv   +1 more source

Invariant manifolds and the geometry of front propagation in fluid flows [PDF]

, 2012
Recent theoretical and experimental work has demonstrated the existence of one-sided, invariant barriers to the propagation of reaction-diffusion fronts in quasi-two-dimensional periodically-driven fluid flows. These barriers were called burning invariant manifolds (BIMs). We provide a detailed theoretical analysis of BIMs, providing criteria for their
arxiv   +1 more source

A Switching Fluid Limit of a Stochastic Network Under a State-Space-Collapse Inducing Control with Chattering [PDF]

arXiv, 2014
Routing mechanisms for stochastic networks are often designed to produce state space collapse (SSC) in a heavy-traffic limit, i.e., to confine the limiting process to a lower-dimensional subset of its full state space. In a fluid limit, a control producing asymptotic SSC corresponds to an ideal sliding mode control that forces the fluid trajectories to
arxiv  

Metric structures of inviscid flows [PDF]

Physica A 258 (1998) 311-328., 1996
An intrinsic metric tensor, a flat connexion and the corresponding distance-like function are constructed in the configuration space formed by velocity field {\bf and} the thermodynamic variables of an inviscid fluid. The kinetic-energy norm is obtained as a limiting case; all physical quantities are Galilean invariant.
arxiv  

Normalizing Flows on Riemannian Manifolds [PDF]

arXiv, 2016
We consider the problem of density estimation on Riemannian manifolds. Density estimation on manifolds has many applications in fluid-mechanics, optics and plasma physics and it appears often when dealing with angular variables (such as used in protein folding, robot limbs, gene-expression) and in general directional statistics.
arxiv  

A geometric look at momentum flux and stress in fluid mechanics [PDF]

arXiv, 2019
We develop a geometric formulation of fluid dynamics, valid on arbitrary Riemannian manifolds, that regards the momentum-flux and stress tensors as 1-form valued 2-forms, and their divergence as a covariant exterior derivative. We review the necessary tools of differential geometry and obtain the corresponding coordinate-free form of the equations of ...
arxiv  

Incompressible Fields in Riemannian Manifolds [PDF]

arXiv, 1999
Incompressible fields are of a special importance in electrodynamics, fluid mechanics, and quantum mechanics. We shall derive a few expressions for such fields in a Riemannian manifold, and show how to generate an incompressible field from an arbitrary set of scalar differentiable functions.
arxiv  

Examining the Uniformity of Flow Distribution in Manifolds

Journal of Applied Fluid Mechanics
Flow distribution uniformity in manifolds is important in various engineering applications. In this study, the effect of manifold design on flow distribution is examined using both experimental and numerical methods.
F. Yazici, M. A. Karadag, P. Gokluberk, A. Kibar   +3 more
semanticscholar   +1 more source

Embedding Camassa-Holm equations in incompressible Euler [PDF]

arXiv, 2018
In this article, we show how to embed the so-called CH2 equations into the geodesic flow of the Hdiv metric in 2D, which, itself, can be embedded in the incompressible Euler equation of a non compact Riemannian manifold. The method consists in embedding the incompressible Euler equation with a potential term coming from classical mechanics into ...
arxiv