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Machinability investigations into special materials. Part 1 stainless steel Rex 448 hardened and tempered to Brinell minimum 321, maximum 375
No full textThis Report deals with the machinability of Firth-Vickers
materials.
Reference REX WO (Stainless Steel) in the hardened and
tempered condition* U,T.S 70-75 tons; Brinell hardness
321 minimum, 375 maximum.
CONTENTS:
SECTION 1 The development of a single point
cutting tool (Lathe Tool).
SECTION 2 The application of this tool to the
turning process to determine the
optimum surface speed and best feed
rate.
SECTION 3 The determination of the life of
the cutting tool when used at
optimum surface speed and best
feed.
SECTION 4 The modification of the single point
tool to meet a special requirement;
i.e. to be applied as a single tooth
in a face milling cutter which is
suitable for use when face milling
Rex 1018 sheet in the hardened and
tempered condition.
The machining process must be designed
to result in the minimum distortion in
the finished component and give a good
surface finish. Further, it is
desirable that the finished dimensions
shall be achieved at one pass and an
area of 32 square feet be covered
between re-grinds of the milling cutter.
SECTION 5 Conclusions.
SECTION 6 Results of practical application.
Report on results of the application
of the proposed cutter design, etc
Report on the machinability of Aircraft Steel D. T. D. 331 (B. S. S. 99) using H. S. S. tools
No full textIn all the tests conducted the results obtained were reasonably
consistent. High Speed Steel Tools containing 18% Tungsten and 5% Cobalt
were used throughout. The same tool was used as far as possible to
minimise the variables entering the tool life tests ... [cont.]
Initial aircraft weight prediction
No full textAlthough much has recently been published concerning methods
for the weight prediction of individual structural components, it is
some considerable time since a review of the subject as a whole has
appeared. This note is an attempt to remedy the situation, the
scope of the work not being limited to aircraft structures but
including also equipment and systems.
Various stages in the design process are considered, commencing
with simple formulae suitable for use in the operations system
stage, passing through the more detailed project stage and finally
recommending methods suitable for weight prediction as the design
becomes established.
In some instances the suggested formulae are well known,
but an effort has been made to utilise the latest available
information in bringing techniques up to date and where possible to
fill in gaps, particularly with respect to equipment and systems
Rolling recrystallisation textures of commercial grades of low carbon steels
No full textThe work in progress concerning the study of rolling-recrystallisation
textures in commercial grades of low-carbon steels is outlined, the influence
of aluminium nitride precipitation and recovery phoenomena being the main
lines of research. Results to date indicate that the retention of the
(100) component of the rolling texture is more favoured during
recrystallisation as the prior recovery times and temperatures are
increased. Textural variations through the sheet thickness are also
being studied, results to date being presented
Aircraft parameter identification using Matlab
No full textSystem identification techniques are routinely used in experimental stability and control
studies throughout the aerospace industry. Over the years, various researchers at the
College of Aeronautics have contributed to this field; most recently some of the latest
methods have been employed to estimate the stability and control derivatives of a variety
of aircraft types. Although the more recent investigations provide a useful insight into
the capabilities and characteristics of several up-to-date methods, they have not resulted
in tools which may be used on a routine basis.
Consequently, the purpose of this report is to describe a set of procedures which are
straightforward to apply, and produce reasonable solutions to the type of linear parameter
identification problems which are often found in aerospace work. Recordings of the short
period and phugoid modes from Handley-Page Jetstream G-NFLC are used throughout as
examples.
Firstly, those characteristics of the aircraft’s instrumentation system which influence
the quality of the signals - sample rate, antialiasing filters, time delays - are considered.
This information is used in conjunction with standard signal processing techniques to
ensure that the data is of sufficient quality to be used in the parameter estimation process.
Next, a basic Fourier analysis and a least squares algorithm are employed to produce non-
parametric and parametric models respectively. The results thus obtained are comparable
to those generated using more sophisticated techniques.
In conclusion, standard signal processing methods combined with relatively simple
estimation theory offer an adequate solution to the linear parameter estimation problem.Cranfield Universit
Fully discrete high-order schemes for hyperbolic conservation law.
No full textIn this paper we investigate fully discrete high-order accurate solutions for system
of hyperbolic conservation laws. Second-, third- and fourth-order high resolution
schemes are presented. Performance of the methods is assessed by solving test
problems for time-dependent Euler equations of Gas Dynamics in one and two space
dimensions. We use exact solutions and experimental data to validate the results.The Universit
Structural impact simulation using program Krash
No full textUse is made of the KRASH program to simulate a simplified car-into-barrier impact. A step-by-step modelling technique is illustrated whose application at an early stage in the design process, allows an understanding of the contribution of individual components to the overall crash-performance of a vehicle.Use is made of the KRASH program to simulate a simplified car-into-barrier impact. A step-by-step modelling technique is illustrated whose application at an early stage in the design process, allows an understanding of the contribution of individual components to the overall crash-performance of a vehicle.This report is a summary of the group design project of the MSc in Astronautics and Space Engineering at Cranfield University for the year 1996/97. The project was a feasibility study of a European unmanned mission to the lunar south pole to carry out scientific study.
The mission proposed uses two spacecraft: (1) an orbiter to take images of the proposed landing site, to measure the Moon’s gravitational field, and to act as a communications relay, and (2) a larger lander which carries a small rover and a crate probe. The orbiter is launched first (if gravity and image data are not already available) so that the lander’s landing site can be selected. The main goal is scientific study of the permanently dark craters at the lunar south pole.
The baseline design (developed to the depth of a feasibility study) meets the stated requirements and is comparable to ESA’s medium class missions (cost € 300 M).CI
Introduction to basic offensive fighter manoeuvres
No full textThe contents of this report were presented during a talk to the Flight Dynamics
and Aerodynamics MSc and PhD students, arranged and supported by the Flight
Dynamics Group of the College of Aeronautics. This talk took place on 17th March
1997 in lecture room C of the College of Aeronautics.
These contents are published under permission of the Hellenic Air-Force
according to OGHA4395.GEE/28-5-97/10:20: 19 document.
The aim of this report is, by gathering essential information from the air combat
literature and relating this information with personal experience, to provide knowledge
about the practical application of some aspects of the Flight Dynamics lecture course
material.The Universit
Comparison if the convergence behaviour of three linear solvers for large, sparse unsymmetric matrices
No full textImplicit methods for the calculation of unsteady flows require the solution of
large, sparse non-symmetric systems of linear equations. The size of such systems
makes their solution by direct methods impractical and consequently iterative
techniques are often used. A popular class of such methods are those based upon the
conjugate gradient method. In this paper we examine three such methods, CGS,
restarted GMRES and restarted GMRESR and compare their convergence properties.The Universit
An evaluation of the comprehensibility of graphical exit signs for passenger aircraft
No full textThe purpose of this report is to present the results of a two phased study which aimed to evaluate the comprehensibility of a number of graphical exit signs for use in passenger aircraft. It is thought that the use of graphical symbols to depict this information has the advantages of being universally comprehensible without dependence on language, while requiring less space to display the signs than using multiple languages.
The results of phase 1 and phase 2 are presented. Phase 1 involved the evaluation of seven graphical signs indicating three meanings: the actual location of an exit, exits located to the left and right, and that the emergency exit(s) was/were located further down the aircraft aisle (straight ahead). The second phase involved the evaluation of three graphical signs (with the same three meanings) in addition to an evaluation of the comprehensibility of their language based equivalents.
An analysis of the comprehensibility of the graphical signs revealed the variants evaluated which indicated the location of the exit were sufficiently understood by members of the traveling public to be put into use. Comprehension of the current language based sign was significantly higher than the best graphical sign for this meaning.
The graphical signs evaluated which indicated that the exits are located to the left and right were also sufficiently understood by the traveling public. Comprehension of the current language based sign was significantly lower than that of the best graphical sign for this meaning.
The graphical signs evaluated which indicated that the exits are located further down the aisle using upwards facing arrows failed to meet the comprehension criteria. The current language based sign also failed to meet the criteria. However comprehension of the best graphical sign was found to be significantly higher than the current language based sign and as such is an improvement to what is currently used.
Specific conclusions related to these signs, and general conclusions regarding the use of graphical symbols to convey this type of information are presents.The Universit