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The lift induced on a circular cylinder by a narrow jet emerging at an angle to the uniform stream
No full textSUMMARY
A preliminary qualitative study has been made in a
smoke tunnel of the flow around a stationary circular cylinder,
having rear jet blowing, placed in a uniform stream. Motographs
have been taken which show many interesting flow phenomena.
A knowledge of these it is hoped will aid future quantitative
studies,
It is found that when the jet is deflected downwards
at an angle to the mainstream direction boundary layer separation
is delayed around the cylinder and the cylinder develops a
lift force in addition to its drag. The delay in boundary
layer separation is suggested to be mainly the result of the
'sink effect' of the jet mixing. The lift, on :the other hand,
appears to be primarily the result of partial attainment of
stagnation pressure on both sides of the jet at exit, and is
therefore of similar origin to the ‘Thwaites’ flap. A smaller,
but no less significant, contribution to the lift arises from
the direct and in91rect effects of the jet blowing
Machinability dynamometers used at the College of Aeronautics
No full textINTRODUCTION
Much more interest in machinability investigations has been shown in
recent years, both by colleges and by Industrial Research departments,
due partly to the difficulty encountered in machining some of the new gas
turbine materials and partly to the availability of simple and economical
dynamometers as are described in this Note.
These dynamometers were designed to provide simple robust
instruments capable of being easily applied to a wide range of machines
without modification. Direct mechanical movement is the basis of their
construction and this has been justified by the trouble free service given
over a period of five years. Almost onehundred of each of these instruments
are being used, and so many requests have been received for a more
comprehensive account of their range of uses that the preparation of this
Note seemed justified.
It is encouraging to see the vigour displayed by industry and the
Colleges in this field since so much remains to be done to establish practical
machinability, data for British materials. By collaboration between
investigators it should be possible to arrange a programme of research
to cover a wide range of materials with the minimum duplication.
The illustrations of the instruments are shown by the courtesy of
Coventry Grinders Ltd. , Coventry
American teaching and practice of industrial engineering and management
No full textIn June 1954 a small mission, comprising T.B.Worth,
A.M.I.E.E., M.I.Prod.E., F.R.S.A., Principal Senior Lecturer in
Production Engineering and Assistant Head of the Department of Mechanical
and Production Engineering at Birmingham College of Technology,
K.J.Shone, M.A. (Cantab),A.M.I.Mech.E., M.I.Ear.E., M.E.I.C., Head of
Department of Industrial Administration, Royal Technical College, Glasgow,
and the author, visited the United States of America to "observe and gain
experience of American methods of training in Industrial Engineering and
Management both in universities and industrial plants". Subsequently, in
September, D.M,Williams, Ph.D., B.Sc., (H.M.I.) joined the mission, which
returned in November 1954.
Each member investigated different aspects and separate reports are being
presented. This report deals mainly with education in Industrial Engineering.
Other Sections, dealing with education in Management, Industrial Engineering
and Management in Industry, Research and Consultancy will be presented
subsequently by the author.
Education in Industrial Engineering in the U.S.A. laid emphasis on the need
for sound education in the bagic and engineering sciences prior to the
study of Industrial Engineering subjects. Considerable attention was paid
to the economic aspects of industry and subjects such as Engineering
Economic Analysis were prominent. Awareness of the impact of new developments
in the industrial engineering field was also evident and curricula
were being revised to introduce subjects such as Electronic Theory into
the electrical programme, and the application of Operations Research
techniques'to the mathematics programme.
The value of formal education in Industrial Engineering was acknowledged by
most industrialists, who were absorbing I.E. graduates at a rate exceeding
1500 per annum.- In 1954 there were approximately 8,000 students enrolled
in. I.E. courses. A comparison of equivalent courses in Great Britain
showed that less than 50 students were enrolled. The comparison also
revealed the inadequacy of the Higher National Certificate courses in
Production Engineering, and a strong plea is made for more facilities for
students to take Higher National Diploma courses in Production Engineering
The design of a multi-cell box in pure bending for minimum weight
No full textThe optimum skin thickness, web thickness and web pitch to
be used for a multi-cell box of given depth under a given
bending load are obtained by two different methods, resulting
in a graph where the optimum geometry is plotted against
the structural index for a given materia
"Investigation into the use of freon 12 as a working medium in a high-speed wind-tunnel"
No full textThe Freon 12 tunnel project at the College of Aeronautics was
started to pin experience in the design of such tunnels and
subsequently to investigate their use for aerodynamic measurements
and the correlation of these with similar measurements in air.
Reports dealing with the use of heavy gases are listed and
the factors affecting the choice of any particular gas are discussed … [cont.]
A nonlinear transportation model: a step-by-step solution
No full textThe model has linear restraints and a functional, to be maximised,
consisting of linear first-order interactions of variables. General
applications of the model are stated. It is shoran that a direct solution
is not generally possible, but iterative procedures, analogous to the
'Transportation' technique are developed both for integer and non-integer
non-negative variables. A Tableau procedure is given, with suitable
checks, to enable a solution to be systematically obtained:, and finally
a numerical example is treated
Thermal buckling of a free circular plate
No full textThe buckling of a free circular plate subjected to a temperature
field, which varies only in the radial direction, is considered. The
problem is first investigated experimentally and the mode of deflection
and form of the temperature distribution are measured. Expressions
are developed for the thermal stresses and the deflection mode of the
plate, which are used for a theoretical small deflection energy analysis.
This solution is found to compare favourably with the experimental
results
A preliminary investigation of the reaction between phenyl glycidyl ether (2.3 epoxy propyl, phenyl ether) and phenyl isocyanate
No full textIsocyanates have been in use for some time as cross-linking agents for polyester
and polyether polymers. These form three-dimensional network polymers on crosslinking
and are familiar commercial materials. This cross-linking system has the
merit that it is possible to produce a wide range of materials from a given isocyanate
or polyester by varying the reaction proportions, catalysts and so on. In addition,
these materials possess a useful range of physical properties. In the present work
the chemical basis of cross-linking epoxide resins with isocyanates has been investigated.
Previous work on the subject has been largely empirical and though certain
workers have produced cross-linked polymers by this means, the precise nature of
the cross-linking process has not been established. As an initial step it was decided
to investigate the nature of the link between the two types of compound, using monofunctional
model compounds. These were phenyl glycidyl ether (2-3 epoxy propyl
phenyl ether), and phenyl isocyanate. Phenyl glycidyl ether resembles in structure
the active part of the epoxide resin molecule, and phenyl isocyanate is similar to
toluene di-isocyanate, which is frequently used in isocyanate cross-linking
mechanisms.
A reaction has been found to take place giving a crystalline material which is a
one-to-one addition compound of the two reagents, together with a red oil, which may
be a mixture of alkyl anilides. The structure of the crystalline material has not been
fully proved, but is believed to be a 2-oxazolidone
The realization of fourth-order rational transfer functions with adjustable coefficients
No full textDesign techniques are described for the simulation of third-order
and fourth-order rational transfer functions with
adjustable coefficients. The realization procedure, which
is based on the use of an ideal computing amplifier associated
with linear passive R.C. two-port networks, is an extension of
the methods described previously(1,2) for quadratic functions