Study of a Real Fluid Flow Axial Symmetry in a Cylindrical Cavity

2012 ◽  
Vol 550-553 ◽  
pp. 929-933
Author(s):  
A. Bouhenna ◽  
Y. Salhi

This paper is devoted to the experimental study of air jet in a cylindrical cavity initially containing air at rest. A set of experiments has been performed to analyze the velocity field in the cavity. The experimental data have been obtained by means of hot wire anemometry, in different sections of the cavity. In addition, flow visualizations were performed using carbon dioxide in solid form. Parallel to this work, we undertook a theoretical study on the same laminar flow, with the same geometric configuration, and it will be the subject to an incoming paper.

2021 ◽  
Vol 2119 (1) ◽  
pp. 012021
Author(s):  
V V Lemanov ◽  
V I Terekhov ◽  
K A Sharov ◽  
A A Shumeiko

Abstract In this work, the experimental data are compared with the version of the “strong” jet (Re ≫ 1) of the exact Landau-Squire solution. The experiments were performed for a submerged air jet flowing out of a tube with a diameter of D = 3.2 mm and a length of more than 100D at a Reynolds number equal to Re = 436. The initial conditions in the jet are the Poiseuille velocity profile, the level of velocity pulsations is less than 1%. Measurements were carried out using a hot-wire anemometer. It is shown that satisfactory agreement with theory is achieved at distances from the tube starting from x/D = 5.6 and up to the zone of transition to turbulence (x/D > 35). Turbulence along the jet axis will increase from 1% to 2.5%, while in the mixing layers it increases to 4.7%.


Author(s):  
Antony N. Beris ◽  
Brian J. Edwards

This much-needed monograph presents a systematic, step-by-step approach to the continuum modeling of flow phenomena exhibited within materials endowed with a complex internal microstructure, such as polymers and liquid crystals. By combining the principles of Hamiltonian mechanics with those of irreversible thermodynamics, Antony N. Beris and Brian J. Edwards, renowned authorities on the subject, expertly describe the complex interplay between conservative and dissipative processes. Throughout the book, the authors emphasize the evaluation of the free energy--largely based on ideas from statistical mechanics--and how to fit the values of the phenomenological parameters against those of microscopic models. With Thermodynamics of Flowing Systems in hand, mathematicians, engineers, and physicists involved with the theoretical study of flow behavior in structurally complex media now have a superb, self-contained theoretical framework on which to base their modeling efforts.


Author(s):  
Peter Atkins

Illustrated with remarkable new full-color images--indeed, one or more on every page--and written by one of the world's leading authorities on the subject, Reactions offers a compact, pain-free tour of the inner workings of chemistry. Reactions begins with the chemical formula almost everyone knows--the formula for water, H2O--a molecule with an "almost laughably simple chemical composition." But Atkins shows that water is also rather miraculous--it is the only substance whose solid form is less dense than its liquid (hence ice floats in water)--and incredibly central to many chemical reactions, as it is an excellent solvent, being able to dissolve gases and many solids. Moreover, Atkins tells us that water is actually chemically aggressive, and can react with and destroy the compounds dissolved in it, and he shows us what happens at the molecular level when water turns to ice--and when it melts. Moving beyond water, Atkins slowly builds up a toolkit of basic chemical processes, including precipitation (perhaps the simplest of all chemical reactions), combustion, reduction, corrosion, electrolysis, and catalysis. He then shows how these fundamental tools can be brought together in more complex processes such as photosynthesis, radical polymerization, vision, enzyme control, and synthesis. Peter Atkins is the world-renowned author of numerous best-selling chemistry textbooks for students. In this crystal-clear, attractively illustrated, and insightful volume, he provides a fantastic introductory tour--in just a few hundred colorful and lively pages - for anyone with a passing or serious interest in chemistry.


1962 ◽  
Vol 17 (1) ◽  
pp. 126-130
Author(s):  
Leon Bernstein ◽  
Chiyoshi Yoshimoto

The analyzer described was de signed for measuring the concentration of carbon dioxide in the bag of gas from which the subject rebreathes in the “rebreathing method” for estimating the tension of carbon dioxide in mixed venous blood. Its merits are that it is cheap, robust, simple to construct and to service, easy to operate, and accurate when used by untrained operators. (Medical students, unacquainted with the instrument, and working with written instructions only, obtained at their first attempt results accurate to within ±0.36% [sd] of carbon dioxide.) The instrument is suitable for use by nurse or physician at the bedside, and also for classes in experimental physiology. Some discussion is presented of the theoretical principles underlying the design of analyzers employing thermal conductivity cells. Submitted on July 13, 1961


The action of anaesthetics on isolated nerve has already been studied by Waller* as regards the effect on the negative variation in the sciatic of the frog, and by myself in mammalian nerves.f In the course of these researches it became evident that the anaesthetics used (chloroform, ether, carbon dioxide) affected not only the negative variation, but also the injury current, and as this action has not been studied before, as far as I am aware, it seemed desirable to investigate the matter not only in nerve, but also in other tissues. The inquiry falls naturally under two heads: first, in how far the phenomena throw light on the processes of nerve action ; and, secondly, as regards the chemical and physical action of anaesthetics on the animal protoplasm generally. These are obviously only parts of the same story, but for convenience I have considered the subject mainly under the first heading in this part, leaving the more general question to a future occasion.


1959 ◽  
Vol 37 (9) ◽  
pp. 1017-1035 ◽  
Author(s):  
John M. Bowsher

The study of the propagation of "plastic" waves in solids has reached a stage where it is necessary to consider which direction future research should take. In the past 90 or so years many experiments, mostly designed to elucidate certain points of engineering significance, and a few attempts at a theoretical study have cast some light on the subject and revealed it as one of formidable difficulty.Nearly all the experiments have of necessity relied on rather dubious theories for their interpretation, and part of the present paper will be devoted to a description of an apparatus which gives results capable of being interpreted with a very minimum of theory. The remainder of the paper is devoted to a short review of past work with particular emphasis on basic phenomena and to a brief discussion on the most pressing problems still remaining. The experiments described in the present paper bring to light a factor in the propagation of "plastic" waves that seems to have been overlooked in previous work.


2018 ◽  
Vol 140 (8) ◽  
Author(s):  
Eduard Amromin

According to several known experiments, an increase of the incoming flow air content can increase the hydrofoil lift coefficient. The presented theoretical study shows that such increase is associated with the decrease of the fluid density at the cavity surface. This decrease is caused by entrainment of air bubbles to the cavity from the surrounding flow. The theoretical results based on such explanation are in a good agreement with the earlier published experimental data for NACA0015.


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