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Eurilia (European Initiative in Library & Information in Aerospace) :
No full textThe study reported here is part of the Eurilia (European Initiative in Library
and Information in Aerospace) project, the aim of which is to enhance the
Libraries’ R&D and education process which underpins the aerospace sector by
establishing a new service based on a standardised pan-European system for
information access, retrieval, image browsing and document delivery. This will
in turn extend the access and availability of major aerospace collections. The
partners in this project are: University of Limerick, Delft University of
Technology, Digital Equipment Corporation, Sup’Aero, ENSAE - Ecole National
Superieure de 1’Aeronautique et de l’Espace, Instituto Nacional de Tecnica
Aeroespacial, Cranfield University The work for this study was largely
undertaken by Cranfield University, but all partners have provided useful input
and comments particularly in terms of the interviews conducted in each Eurilia
country. The University would also wish to thank the EC European Action
Programme for Libraries for the support for Eurilia in general and this phase of
the project in particular. This report was originally submitted to the EC as
Eurilia (European Initiative in Library and Information in Aerospace), Pre-
project Audit, Project LIB-EURILIA/3-2083 funded by the European Action
Programme for
The time to achieve peak output with special reference to aircraft production
No full textDuring the war, the rate of production which could be expected from an organisation setting out to manufacture a new type of aircraft was of great interest from the planning point of view. It was found that a time of the order of twelve to eighteen months elapsed between the delivery of the first production type and the achievement of the peak rate of production for which the factory was planned. This report analyses how this growth takes place and used the theoretical growth curve, known as the Logistics, for fitting smooth curves to a large amount of date from several countries. From the Logistic formula an index of the rate of growth for judging the relative performances in different projects has been evolved. Its use includes also the planning of production schedules. The factors determining the rate of growth are investigated but these would appear to be more in the intangible category rather than among the simple physical conditions such as size of programme or of aircraft
Nose controls on delta wings at supersonic speeds
No full textExpressions are derived for lξ and a2 of nose ailerons and nose elevators on a delta wing, as depicted in Fig. 1, in supersonic flight. Nose and trailing edge controls on delta wings in supersonic flight are compared
Research on the effect of mixture quality on the exhaust gas emissions of a petrol engine
No full textTo meet the existing and proposed legislation for the control
of air pollution by the exhaust emissions of petrol engines, a
major research effort is required within the next five years. Not
only are the regulations expected to become more stringent as the
number of motor vehicles increases, but improvements will show a
diminishing; return in terms of the percentage reduction of emissions
when primary factors have been treated. A fundamental problem that
is not well understood is the effect of the quality of the fuel-air
mixture on combustion in the spark ignition engine. Knowledge of
this factor could be important when the emissions are at a low
level as a consequence of the employment of devices that treat
factors such as mixture strength or the distribution of the fuel.
Although the devices are effective in the reduction of the concentrations
of hydrocarbons it is thought that many have an undesirable
effect on the concentrations of the oxides of nitrogen.
To improve the knowledge of these problems, it is the proposal
that the research at the Advanced School of Automobile Engineering
should be extended to a comprehensive study of the effects of
mixture quality on the concentrations of carbon monoxide, hydrocarbons
and oxides of nitrogen in the exhaust gas of a spark
ignition engine. The facilities at the School are comprehensive
and no financial assistance is requested for equipment. To allow
the study to be completed within a time that is relevant to the
urgency of the problem, a grant is requested for the employment of
a Senior Technical Officer and a Laboratory Technician for a period
of three years
Factors controlling gas turbine combustion performance at high pressure
No full textIn the post most of the research work carried out in gas turbine
combustion was mainly concerned with performance problems arising at
high altitudes. these were primarily problems of trying to achieve
high combustion efficiency, adequate stability and good relighting
performance. This research necessitated the use of expensive test
facilities to provide large quantities of air at sub atmospheric pressure.
For this reason much effort was expended in trying to find methods of
simulating low combustion pressures, and in the development of
correlating parameters which would allow low pressure performance to be
predicted from experimental data obtained at more convenient levels
of pressure.
In recent years, however, there has been a marked trend towards
engines of higher compression ratio. This is illustrated in figure 1
which was reproduce& from a paper by Pearson. This trend has not
produced any new problems, with the possible exception of exhaust smoke,
but it has aggravated many problems which previously caused no great
concern, and it has exposed many deficiencies in our knowledge of
certain basic processes, particularly those affecting combustion and
heat transfer at high pressure. One object of this paper is to examine
the influence of pressure on various aspects of combustion performance.
Another object is to derive formulae from which the influence of
increasing pressure on various performance criteria can be estimated.
One important effect arising at high pressures is an increased
dependence of all aspects of combustion performance on fuel spray
characteristics. Because of their importance and because so far they
appear to have received comparatively little attention, much of this
paper is devoted to the effect of pressure on various spray properties
such as penetration, droplet size and cone angle
An assessment of the critical strains which can be sustained by a mar-ageing steel under bi-axial tension
No full textMar-ageing steels are being specified more and more in advanced
engineering applications, and, frequently, the components are manufactured
from sheet material. Consequently, the evaluation of the sheet forming
properties of this material is of paramount importance; this investigation
forms part of this general program.
The aim here is two-fold, firstly, to determine the maximum strain
which can be sustained under bi-axial stress, and secondly, to suggest any
way in which this value can be increased
Some aspects of electro-chemical grid-marking
No full textIntroduction
The value of fine grids, electromarked (1) on to metal sheets
before pressing, so that the type and magnitude of the strain developed
in the critical region of the pressing can be assessed, is undisputed.
Keeler (2), Meyer and Newby (3), and Goodwin (4), have all discussed
practical applications of this technique and Palmer (5) has reviewed
the field and introduced the concept of a relative safety factor (MSF).
However it may be useful to see what this 'mark' consists of, how the
marking affects the subsequent metal performance, what the limitations
of the process are and other peripherical issues. It is these aspects
of the process which is the concern of this paper
Optimum structures
No full textThe design of the best structure for a given purpose
depends upon the criterion used for optimisation. Structures
may be designed to safely transmit a given system of forces using
the least weight of material.. They may also be designed to have
maximum stiffness of a certain type for a given weight or
alternatively to have the greatest possible fundamental
frequency of vibration. These problems, although in general
distinct from one another, are closely related and much can be
achieved towards maximisation of stiffness and frequency by the
use of minimum weight designs. In fact it can be shown that a
minimum weight framework is the stiffest structure of that weight
for the force system, which it is designed to carry.x
The present report is concerned exclusively with the problem of
the design of structures of minimum weight, which are required
to transmit specified forces. Some attention will be given to
frameworks because, in particular, methods of approximate
numerical analysis are more readily formulated for this type of
structure, but the main emphasis will be placed upon the design
of structures formed from plates of variable thickness reinforced
by direct load carrying members.
See para,l.
Test report No. PLBO/4: wear tests on PERPRO tools grades N35/RD25 and N35/RD80 machining EN 9
No full textTools of grade N35/RD25 and N35/RD80 were tested at 500 fpm cutting
speed, 0.010 in/rev feed and 0.10 in. depth of cut on EN 9 to 0.030 in.
flankwear. The results showed that there was no significant difference
in tool life between the two grades for the cutting conditions investigated
Test report no. PLBO/6: wear tests of PERPRO tools grade CLV, machining meehanite
No full textTools of grade CLV were tested at 300 fpm cutting speed, 0.010
in./rev. feed and 0.10 in. depth of cut to 0.030 in. flankwear. The
results gave a mean tool life of 37 minutes which should be compared with the results given in Report No. PLB0/1 for grades CLV 403, A, B and C