On the Effective “Length” of Two-Dimensional Contracting Ducts

1966 ◽  
Vol 70 (666) ◽  
pp. 676-676 ◽  
Author(s):  
J. C. Gibbings
Keyword(s):  
Effective Length ◽  
Two Dimensional ◽  
Asymptotic Value ◽  
Points Of Interest ◽  
Centre Line ◽  
Boundary Slope

The note by W. T. F. Lau upon the effective “length” of two-dimensional contracting ducts has raised further points of interest.Lau's paper presents three different criteria which can control a contraction length. Of these three, the second and third, that respectively are based upon the approach of the centre-line velocity to its asymptotic value and upon the approach of the flow to uniformity, were compared in ref. 1. The first criterion that is based upon the approach of the boundary slope to zero is not in general identical with the second.

On the Length of Two-Dimensional Contractions

1966 ◽  
Vol 70 (666) ◽  
pp. 673-675 ◽  
Author(s):  
W. T. F. Lau
Keyword(s):  
Mean Value ◽  
List Type ◽  
Two Dimensional ◽  
Type Number ◽  
Asymptotic Value ◽  
Centre Line ◽  
Boundary Slope

In a recent paper, Gibbings has made an interesting comparison of the length of two-dimensional contractions based on three criteria, namely:(1)the rapidity with which the boundary slope approaches its zero value;(2)the rapidity with which the centre-line velocity approaches its asymptotic value; and(3)the degree of uniformity of the velocity expressed as a percentage of its mean value.

scholarly journals A study on the inertial effective length of two-dimensional centrifugal impeller flow channel.

1991 ◽  
Vol 57 (533) ◽  
pp. 121-128
Author(s):  
Eisaku O'KUBO ◽  
Yasufumi HAKAMATA ◽  
Yoshinobu TSUJIMOTO ◽  
Tomomasa UEMURA ◽  
Hiromu TSURUSAKI
Keyword(s):  
Flow Channel ◽  
Effective Length ◽  
Centrifugal Impeller ◽  
Two Dimensional

On the chordwise lift distribution at the centre of swept wings

1950 ◽  
Vol 2 (2) ◽  
pp. 146-154 ◽  
Author(s):  
D. Küchemann ◽  
J. Weber
Keyword(s):  
Flat Plate ◽  
Present Note ◽  
Two Dimensional ◽  
Special Configuration ◽  
Vortex Strength ◽  
Vortex Lines ◽  
Lifting Surface ◽  
Centre Line ◽  
Trailing Vortices ◽  
Swept Wings

SummaryThe present note deals with the peculiarities of the lift distribution on swept wings. The influence of the angle of sweep is expected to be greatest in its effect on the chordwise lift distribution at the centre section of the wing. It is assumed that the essential characteristics of this chordwise lift distribution are predominantly determined by the special configuration of the bound vortices and not so much by the trailing vortices. In calculating the downwash, induced by a continuous chordwise distribution of swept vortex lines of infinite span, it is found that the downwash at the centre line is to be expected to differ from its two-dimensional form mainly by a term proportional to the local vortex strength. Solutions of this simplified downwash equation have been obtained. They differ from the ordinary fiat-plate distribution only in the exponent which instead of becomes .It is suggested that this type of function is more appropriate for the centre-section of swept wings and that it may replace the ordinary flat-plate distribution in all those cases where the lifting surface is swept.

scholarly journals NEW RESULTS FOR THE DYNAMICAL CRITICAL BEHAVIOR OF THE TWO-DIMENSIONAL ISING MODEL

2004 ◽  
Vol 15 (08) ◽  
pp. 1069-1073 ◽  
Author(s):  
DANIEL TIGGEMANN
Keyword(s):  
Ising Model ◽  
Critical Exponent ◽  
Critical Behavior ◽  
New World ◽  
Research Center ◽  
Two Dimensional ◽  
World Record ◽  
Asymptotic Value ◽  
Logarithmic Corrections

Using the new supercomputer JUMP at the Research Center Jülich, we were able to simulate large lattices (up to L=2·106, a new world record) for long times (up to T=6000 for L=1.5·105). Using this data, we examined the dynamical critical exponent z. The old assumption of z=2 with logarithmic corrections seems very unlikely according to our data, leaving the asymptotic value of z≃2.167.

The plane turbulent impinging jet

1978 ◽  
Vol 88 (4) ◽  
pp. 737-756 ◽  
Author(s):  
E. Gutmark ◽  
M. Wolfshtein ◽  
I. Wygnanski
Keyword(s):  
Experimental Study ◽  
Viscous Dissipation ◽  
Impinging Jet ◽  
Turbulent Structure ◽  
Two Dimensional ◽  
Spectral Measurements ◽  
Mean Velocity ◽  
Centre Line ◽  
The Mean ◽  
Energy Balances

This paper presents an experimental study of the turbulent structure on the centre-line of a two-dimensional impinging jet. The mean velocity, turbulent stresses, triple velocity products and temporal derivatives were measured and the energy balances for the three fluctuating components were calculated. The results indicate a selective stretching of vortices in the direction in which the streamlines spread near the wall, causing anisotropy in this region. The distribution of energy among various frequencies was found from spectral measurements. These measurements revealed the existence of a neutral frequency above which the energy was attenuated by viscous dissipation and below which it was augmented by a vortex-stretching mechanism.

Spectrophotometric measurements of objective-prism spectra

1966 ◽  
Vol 24 ◽  
pp. 118-119
Author(s):  
Th. Schmidt-Kaler
Keyword(s):  
Progress Report ◽  
Two Dimensional ◽  
Objective Prism ◽  
Made In

I should like to give you a very condensed progress report on some spectrophotometric measurements of objective-prism spectra made in collaboration with H. Leicher at Bonn. The procedure used is almost completely automatic. The measurements are made with the help of a semi-automatic fully digitized registering microphotometer constructed by Hög-Hamburg. The reductions are carried out with the aid of a number of interconnected programmes written for the computer IBM 7090, beginning with the output of the photometer in the form of punched cards and ending with the printing-out of the final two-dimensional classifications.

Introductory paper

1966 ◽  
Vol 24 ◽  
pp. 3-5
Author(s):  
W. W. Morgan
Keyword(s):  
Line Intensity ◽  
Classification Scheme ◽  
Two Dimensional ◽  
Spectral Classification ◽  
Dimensional Array ◽  
Rr Lyrae ◽  
Metallic Line ◽  
Introductory Paper ◽  
Parameter Varying ◽  
Definition Of

1. The definition of “normal” stars in spectral classification changes with time; at the time of the publication of theYerkes Spectral Atlasthe term “normal” was applied to stars whose spectra could be fitted smoothly into a two-dimensional array. Thus, at that time, weak-lined spectra (RR Lyrae and HD 140283) would have been considered peculiar. At the present time we would tend to classify such spectra as “normal”—in a more complicated classification scheme which would have a parameter varying with metallic-line intensity within a specific spectral subdivision.

A one-dimensional self-gravitating stellar gas

1966 ◽  
Vol 25 ◽  
pp. 46-48 ◽  
Author(s):  
M. Lecar
Keyword(s):  
Gravitational Field ◽  
Phase Space ◽  
Motion Picture ◽  
Space Distribution ◽  
Two Dimensional ◽  
One Dimensional ◽  
Phase Space Distribution ◽  
Dimensional Phase Space ◽  
The Mean

“Dynamical mixing”, i.e. relaxation of a stellar phase space distribution through interaction with the mean gravitational field, is numerically investigated for a one-dimensional self-gravitating stellar gas. Qualitative results are presented in the form of a motion picture of the flow of phase points (representing homogeneous slabs of stars) in two-dimensional phase space.

Analysis of the 9th November 1990 flare

2000 ◽  
Vol 179 ◽  
pp. 229-232
Author(s):  
Anita Joshi ◽  
Wahab Uddin
Keyword(s):  
Image Processing ◽  
Two Dimensional ◽  
Temporal Behaviour ◽  
Contour Maps ◽  
Dimensional Measurements ◽  
Processing Software ◽  
Image Processing Software

AbstractIn this paper we present complete two-dimensional measurements of the observed brightness of the 9th November 1990Hαflare, using a PDS microdensitometer scanner and image processing software MIDAS. The resulting isophotal contour maps, were used to describe morphological-cum-temporal behaviour of the flare and also the kernels of the flare. Correlation of theHαflare with SXR and MW radiations were also studied.

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