Author: Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 632
Book Description
87-0350-87-0399
Author: Aerospace America
Author: Scientific and Technical Aerospace Reports
Author: Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 456
Book Description
Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Particle Image Velocimetry
Author: Ronald J. AdrianPublisher: Cambridge University Press
ISBN: 0521440084
Category : Science
Languages : en
Pages : 585
Book Description
Particle image velocimetry, or PIV, refers to a class of methods used in experimental fluid mechanics to determine instantaneous fields of the vector velocity by measuring the displacements of numerous fine particles that accurately follow the motion of the fluid. Although the concept of measuring particle displacements is simple in essence, the factors that need to be addressed to design and implement PIV systems that achieve reliable, accurate, and fast measurements and to interpret the results are surprisingly numerous. The aim of this book is to analyze and explain them comprehensively.
International Aerospace Abstracts
Author: Fluid Mechanics and Fluid Power, Volume 7
Author: Krishna Mohan SinghPublisher: Springer Nature
ISBN: 9819970474
Category : Technology & Engineering
Languages : en
Pages : 355
Book Description
This book comprises select peer-reviewed proceedings of the 9th International and 49th National Conference on Fluid Mechanics and Fluid Power (FMFP 2022). This book brings together scientific ideas and engineering solutions put forth by researchers and practitioners from academia and industry in the important and ubiquitous field of fluid mechanics. The contents of this book focus on fundamental issues and perspective in fluid mechanics, measurement techniques in fluid mechanics, computational fluid and gas dynamics, instability, transition and turbulence, fluid-structure interaction, multiphase flows, microfluidics, bio-inspired fluid mechanics, aerodynamics, turbomachinery, propulsion and power and other miscellaneous topics in the broad domain of fluid mechanics. This book is a useful reference to researchers and professionals working in the broad field of mechanics.
The Finding Guide to AIAA Meeting Papers
Author: American Institute of Aeronautics and Astronautics. Technical Information ServicePublisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 764
Book Description
Applied mechanics reviews
Author: Paper
Author: Publisher:
ISBN:
Category : Mechanical engineering
Languages : en
Pages : 768
Book Description
The Effects of Viscoelasticity on the Transitioning Cylinder Wake
Author: David Hastings RichterPublisher: Stanford University
ISBN:
Category :
Languages : en
Pages : 166
Book Description
Using a newly developed three dimensional, time dependent finite volume code designed to compute non-Newtonian flows over a large range of Reynolds number (Re), we performed simulations of viscoelastic flow past a circular cylinder. Our goal was to elucidate elastic effects during transition to turbulence in a bluff body wake. Based on its ability to capture essential physical processes in turbulent drag reduction studies, the FENE-P rheological model was employed in the calculation, and the numerical method utilized was such that a large range of rheological parameters (polymer length L, dimensionless Weissenberg number (Wi), and polymer concentration (beta) in the FENE-P model) could be probed. Simulations were performed for Reynolds numbers ranging from Re = 100 to Re = 3900. Within this range, the Newtonian cylinder wake first undergoes a series of secondary instabilities, transitioning the wake structure from a two-dimensional, laminar vortex shedding state to one exhibiting three-dimensional motion. This transition is characterized first by the mode A instability, which develops in the region of primary vortex development at a Reynolds number of Re = 190. The mode B instability then follows at Re = 260, resulting from unstable perturbation growth in the braid region between primary vortices. At still higher Reynolds numbers, Re = O(1000), the separated shear layer immediately behind the cylinder begins to transition prior to primary vortex shedding. Through nonlinear simulations as well as a Floquet linear stability analysis, viscoelasticity was observed to stabilize both regimes of three-dimensional transition. Full nonlinear simulations revealed that for high enough polymer extensibility L at Re = 300, where mode B instability structures dominate for Newtonian flow, the wake could be reverted back to a state resembling two-dimensional, laminar vortex shedding. This was then confirmed using a Floquet stability analysis, showing significantly suppressed growth rates for both the mode A and mode B instabilities in the linear regime of their development. Mechanisms of this stabilization are presented. At Re = 3900, viscoelasticity again stabilizes the flow, though at this point through a suppression of the Kelvin-Helmoltz rollup instability present in the separated shear layer for Newtonian flows. Once a primary Karman vortex is allowed to form without the influence of a transitioned shear layer, the wake then reverts back to one resembling the mode B instabilities. Confirming this, a study was then performed at the same Reynolds number but allowing for an inhomogeneous polymer concentration throughout the flow field. By injecting polymer additives on the upstream side of the cylinder, it was found that stabilization of the shear layer and of the subsequent wake could be achieved without the presence of polymeric stresses in all downstream locations of the flow.