Scientific and Technical Aerospace Reports

Scientific and Technical Aerospace Reports
Author:
Publisher:
Total Pages: 1460
Release: 1991
Genre: Aeronautics
ISBN:

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.

An Introduction to Turbulent Reacting Flows

An Introduction to Turbulent Reacting Flows
Author: R. S. Cant
Publisher: Imperial College Press
Total Pages: 192
Release: 2008
Genre: Science
ISBN: 1860947786

Provides physical intuition and key entries to the body of literature. This book includes historical perspective of the theories.

Turbulence Measurements in Axisymmetric Jets of Air and Helium

Turbulence Measurements in Axisymmetric Jets of Air and Helium
Author: N. R. Panchapakesan
Publisher:
Total Pages: 226
Release: 1991
Genre:
ISBN:

A turbulent round jet of air discharging into quiescent air was studied experimentally. X-wire hot-wire probes mounted on a moving shuttle were used to eliminate rectification errors due to flow reversals in the intermittent region of the jet. Moments of velocity fluctuatuions up to fourth order were measured to characterize turbulent transport in the jet and to evaluate current models for triple moments that occur in the Reynolds stress equations. Fourth moments were very well described in terms of second moments by the quasi-gaussian approximation across the entire jet including the intermittent region. Profiles of third moments were found to be significantly different from earlier measurements. The Basic triple moment model that inlcluded turbulent production and models for the dissipations and the return to isotropy part of the pressure correlations was found to be unsatisfactory. When mean-strain production and a model for rapid pressure correlations were also included, predictions were satisfactory in the fully turbulent region.

Frontiers in Fluid Mechanics

Frontiers in Fluid Mechanics
Author: Stephen H. Davis
Publisher: Springer Science & Business Media
Total Pages: 299
Release: 2012-12-06
Genre: Technology & Engineering
ISBN: 3642465439

Turbulent Mixing in Nonreactive and Reactive Flows

Turbulent Mixing in Nonreactive and Reactive Flows
Author: S. Murthy
Publisher: Springer Science & Business Media
Total Pages: 469
Release: 2013-11-11
Genre: Science
ISBN: 1461587387

Turbulence, mixing and the mutual interaction of turbulence and chemistry continue to remain perplexing and impregnable in the fron tiers of fluid mechanics. The past ten years have brought enormous advances in computers and computational techniques on the one hand and in measurements and data processing on the other. The impact of such capabilities has led to a revolution both in the understanding of the structure of turbulence as well as in the predictive methods for application in technology. The early ideas on turbulence being an array of complicated phenomena and having some form of reasonably strong coherent struc ture have become well substantiated in recent experimental work. We are still at the very beginning of understanding all of the aspects of such coherence and of the possibilities of incorporating such structure into the analytical models for even those cases where the thin shear layer approximation may be valid. Nevertheless a distinguished body of "eddy chasers" has come into existence. The structure of mixing layers which has been studied for some years in terms of correlations and spectral analysis is also getting better understood. Both probability concepts such as intermittency and conditional sampling as well as the concept of large scale structure and the associated strain seem to indicate possibilities of distinguishing and synthesizing 'engulfment' and molecular mixing.