CoA. Notes (1952-1969)

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2-port as an anlalogue of the Lorentz transformation of special relativity theory
(College of Aeronautics, 1961-04) Deards, S. R.
If the variables associated with a linear resistance 2-port are identified with the variables of special relativity theory, it is shown that a resistance 2-port transforms its port variables according to the Lorentz equations.
Open Access
The acquisition of high speed skills. First progress report on D.S.I.R. research project
(College of Aeronautics, 1963-04) Whitfield, D.
N/A
Open Access
The aerodynamic characteristics of the jet wing and its application to high speed aircraft
(College of Aeronautics, 1961) Alexander, A. J.
The slender wings and bodies suitable for supersonic flight have, in general, relatively poor aerodynamic characteristics especially at lay speeds. In order to improve their performance the use of edge blowing has been explored. In this scheme high velocity air jets in the form of thin sheets are used to fix separation lines on the wing or body and to favourably influence the external stream. Thus the equivalent wing, called here the "Jet Wing” is composed of the wing-body itself plus the extended curved jet sheets which spring from its edges. A limited use of edge jets has been proposed in the 'Jet Flap' concept but the efficiency of this device fails off with decreasing aspect-ratio and the problem of trimming could be severe as most of the increased lift is generated near the trailing edge. At very law aspect-ratios a considerable part of the lift is contributed by the leading-edge vortices which dominate the flow field at moderate incidence. It follows therefore that leading edge blowing is particularly useful for small aspect-ratio wings and the trimming problem can be avoided by a suitable jet arrangement which does not disturb the conical nature of the flow. When sufficiently large auxiliary thrusts are available peripheral jet sheets can be deflected downwards close to the ground, the air craft becoming a Ground-Effect-Machine, with substantial reductions in both take-off and landing speeds and distances.
Open Access
Aerodynamic characteristics of two low aspect ratio rectangular wings at Mach 2
(College of Aeronautics, 1956-04) Marson, G. B.
This note summarises the important results of a detailed experimental investigation into the flow and pressure distribution over two rectangular single wedge wings. The experiments were carried out .in the 9" x 9" supersonic tunnel at the College of Aeronautics, 6 at a Mach number of 2.0 and a Reynolds number of 2.5 x 10 per foot. Both wings had a chord of 3 inches and a total wedge angle of 6°. They had no real trailing edge, but were faired into a cylindrical support which could be rolled and pitched in the tunnel. Wing A was of 2 inch1span, giving an aspect ratio of 0.67. `Ting B was of 1 1/4 inch span, 0.42 aspect ratio. 132 pressure tappings 4 were spaced regularly over half of one surface of each wing, and up to 19 pressure readings could be taken simultaneously on vertical mercury manometers. models were pressure plotted at pitch angles of 0°, 2 1/2°, 5°, 7 1/2°, 10°, 15°, 20°, 25°, and 30°, and at all roll angles at intervals of 30°. Since each wing was symmetrical about the centreline, the complete pressure distribution over all surfaces at any roll angle Ø could he obtained from the readings taken on the one surface at Ø, 180°- Ø, 180° + Ø, and 360°- Ø. The pressure readings were then integrated to give the forces and moments on the complete wing… [cont.].
Open Access
American teaching and practice of industrial engineering and management
(College of Aeronautics, 1956-02) Cherry, J.
In 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.
Open Access
An analysis of an unstiffened cylindrical shell subjected to internal pressure and axial loading
(College of Aeronautics, 1961-03) Houghton, D. S.; Johns, D. J.
General equations are obtained for the deflections and stresses in long thin unreinforced cylinders, which are subjected to an axial load and internal pressure. By making suitable simplifying assumptions, results are presented which show the variation of the structural weight parameter with the structural axial loading index, for both pressurised and unpressurised shells. An allowance is made for the effects of shell initial eccentricities on the buckling stress coefficient K, in accordance with R. Ae.S. data sheet 04.01.01. Extreme cases are considered, in which the shell is assumed to be either fully effective (K = 0.6). 0:. completely ineffective (K = 0), in resisting axial compressive loads. For this latter case, complete pressure stabilisation of the shell is considered, and it is shown that the weight penalty involved in using this design philosophy, is negligible for a certain range of the structural loading index. A simple modification to the analysis for this case, i.e. K = 0, is made to allow for the effect of an external longitudinal bending moment.
Open Access
Atmosphere breathing engines in astronautics
(College of Aeronautics, 1958-10) Greenwood, S. W.; Carton, D. S.
The contents of this note fall into two sections. Part I considers the possibilities and problems involved in using ramjets as a power source for one of the stages of a satellite launching vehicle or similar project. In comparing such a system with rocket powered vehicles, consideration is given to both performance and mass of the various systems. Various trajectories are considered. This work includes a reassessment of projects that have been suggested elsewhere. The second part examines the possibility of using forms of ramjet in the atmosphere of other planets. Because there is insufficient knowledge of these atmospheres, a study has been carried out to determine the approximate performance of a chemical ramjet in atmospheres of Methane, Ammonia, Hydrogen and Carbon Dioxide at Mach 3. The work in Part II is original, there being no previously reported papers on the subject known. These studies, which are necessarily based on several simplifying assumptions, indicate that applications for these engines may be expected to arise in astronautics, and that this is a fruitful field for further studies.
Open Access
Avoidable delays among women workers on light work
(College of Aeronautics, 1955-02) Williams, J. A. C.
SUMMARY Time Study makes use of certain allowances in correcting observed times to standard times. One allowance, the 'fatigue' allowance of F.W. Taylor, allocates a certain period of the working day to rest on a basis of conditions of work. The allowance is now termed Compensating Rest (C.R.) Allowance and is given for a variety of psycho-physiological conditions of work. A study of women workers in light industry is reported which measures the time spent not working, in talking etc. From this study causal factors effecting time not working are considered and certain recommendations are made as to values for C.R. Allowances covering certain factors in the work situation. The method of study employed was that of ratio delay originated. by L.H.C. Tippett and some comment is made on its application.
Open Access
A bibliography and survey of the vortex tube
(College of Aeronautics, 1954-03) Westley, R.
A comprehensive bibliography of vortex tube publications is given together with a brief survey of the development of the vortex tube between 1931 and 1953.
Open Access
The calculation of the wave drag of a family of low-drag axisymmetric nose shapes of fineness ratio 4.5 at zero incidence at supersonic speeds
(College of Aeronautics, 1954-05) Marson, G. B.
The pressure drag coefficients of a particular family of convex logarithmic projectile nose shapes in which the nose angle is an important parameter have been calculated over a range of supersonic Mach numbers using a rapid approximate method due to Zienkiewicz.5 The optimum nose angle for minimum wave drag of these profiles for each Mach number has been obtained. It is shown that above N = 1.5„ approximately, the optimum shape is similar to the hypersonic optimum profile and has the sane or- less wave drag than this profile. However for values of M/F, where P is the fineness ratio, below 0.5, both the hypersonic and the logarithmic optimum profiles have a higher drag than the so-called cubic profile (Ref, 9).
Open Access
The characteristics of the flow field over the mid-upper fuselage of Lancaster P. A. 474
(College of Aeronautics, 1956-01) Burrows, F. M.
This note describes a series of tests conducted to determine the characteristics of the flow field over the mid-upper fuselage of. Lancaster P. A, 474. The range of the tests was to include a determination of the distributions of total head, static pressure and velocity together with the flow directional characteristics in the pitching plane for a number of aircraft flight configurations as listed in paragraph 1. 2. Curves are presented in Figs. 9, 20 - 25, showing the flow directional characteristics and the distributions of static pressure and velocity in the region of investigation.
Open Access
Characteristics of the high temperature mechanisms of creep and recovery in graphite
(College of Aeronautics, 1963) College of Aeronautics, (Cranfield)
The research reported in this document has been made possible through the support and sponsorship of the U.S. Department of the Army, through its European Research Office. This report, not necessarily in final form, is intended only for the internal management use of the Contractor and the 1.T.S. Department of the Army.
Open Access
Characteristics of the high temperature mechanisms of creep and recovery in graphite
(College of Aeronautics, 1962) College of Aeronautics, (Cranfield)
The research reported in this document has been made possible through the support and sponsorship of the U.S. Department of the Army, through its European Research Office. This report, not necessarily in final form, is intended only for the internal management use of the contractor and the U.S. Department of the Army.
Open Access
Characteristics of the high temperature mechanisms of creep and recovery in graphite
(College of Aeronautics, 1962) College of Aeronautics, (Cranfield)
The report summarizes the first year's work carried out on an investigation into the high temperature mechanisms of creep and recovery in graphite. This work has been devoted to the building of an experimental apparatus capable of exerting creep loads in the temperature range 2000°C — 3000°C. A full description of the apparatus is given and its further potential discussed. Detailed figures are included on the labour expended together with a summary of property acquired for use on the contract.
Open Access
Characteristics of the high temperature mechanisms of creep and recovery in graphite: part 3
(College of Aeronautics, 1963-04) College of Aeronautics, (Cranfield)
The research reported in this document has been made possible through the support and sponsorship of the U.S. Department of the Army, through its European Research Office. This report, not necessarily in final form, is intended only for the internal management use of the Contractor and the U.S. Department of the Army.
Open Access
Clearance fits and the limits on mating parts
(College of Aeronautics, 1959-09) Harris, J. T.
N/A
Open Access
Compensating rest allowances: some findings and implications for management arising from recent research
(College of Aeronautics, 1956-10) Belbin, R. M.
In November 1953 a research project was started at the College of Aeronautics to study Work Study rating, rest and fatigue allowances. This project has been carried out under the sponsorship of the Department of Scientific and Industrial Research with counterpart funds made avail¬able through the Conditional Aid Scheme. At the commencement of this project it was agreed that our special concern would be rest allowances and that we would consider rating only in so far as it became a necessary part of our study of rest allowances. This report is not intended to present results covering the whole of our investigations. The work carried out by.J. A, C. Williams who was any colleague in research until April, 1956 has been presented in previous reports and these are referred to in our list of references. Mr Williams has been especially concerned with the problem of heat stress and with the determination of a rational basis for Compensating Rest Allowances in relation to known heat loads. While this report cannot be regarded therefore as comprehensive it is hoped that for the general reader it will, however, cover sufficiently wide ground to justify some of the general conclusions that are reached at the end of this paper.
Open Access
Conversion from military to civil standard of varsity WF.415 now G-APAZ and its preparation for use by Smiths aircraft instruments in accordance with the terms of M.O.S. contract 6/aircraft/14707/CB6(a)
(College of Aeronautics, 19) Gover, H. W.
SUMMARY OF REQUIREMENTS AND BRIEF DESCRIPTIONS Varsity WF.415 was delivered as a standard aircrew training aircraft and had been in storage at No. 48 MX., Hawarden, for a considerable period. Under the contract the College was required to:- 1. Prepare the aircraft for delivery flight to Cranfield, 2. Carry out a Major Inspection. 3. Embody all outstanding modifications as required by R.T.O.Vickers. 4. Convert the aircraft from military to civil category. 5. Embody the required special modifications (listed in Part 4,Section 1). 6. Maintain the aircraft during a period of proving flights and. A,R,B. Test Flights. Prior to the delivery flight a discussion took place with the S.T.O. Hawarden. On the basis of this meeting a list of minimum requirements was raised by the Chief Inspector to fitness for flight to a one flight standard. A party of College employees was sent to prepare the aircraft, the operation taking five days. On arrival at Cranfield the aircraft underwent an acceptance check and was completely stripped. The Inspection Schedule and. Varsity Modification requirements were raised. During the period required for the design of special modifications, the Major Inspection was carried out and the standard modifications embodied. It was decided that the sections of the aircraft affected by the special modifications (mainly cabin and cockpit area) would be inspected for defects and that the major inspection would be carried out on completion of these special modifications. This ensured that the spares required in these sections would. be readily available and the major inspection, when carried out, would not uncover any serious defects. To avoid unnecessary load on the Design Department it was decided that during this period certain of the special modifications should be embodied to Flight Department drawings approved by Design The work was confined to non-structural parts. This permitted completion of a considerable number of the special modifications during overhaul, thereby releasing skilled man power for the more extensive special modifications as they were designed. During the period, close liaison was maintained with Design Department to ensure that equipment required would be available on receipt of drawings, thus avoiding, as far as possible, delay due to protracted delivery dates.
Open Access
Conversion of Douglas Dakota G-AMZE for Smith autopilot type D development
(College of Aeronautics, 1953-11) Firth, A.
Dakota K.J. 874 was delivered as a standard R.A.F Mark IV paratrooping aircraft. The undermentioned modifications were called for in order, to convert it to an aircraft suitable for the carrying out of flight tests & development on the Type "D" Auto Pilot", bearing in mind the lessons learned from previous operations of a Valetta on similar work. The requirement that the aircraft be placed in a civil category for maintenance entailed the conversion being carried out by a Firm approved by the Air Registration Board for overhaul and maintenance, including Radio, also approved for Design. After discussion, the contract was placed with the College of Aeronautics, Cranfield, whose maintenance and design organization is fully A.R.B. approved, the aircraft being delivered during February, 1953. The first requirement was the removal of all surplus equipment from the airframe. This included all the paratrooping gear, the seating, which was unsuitable since it ran the full length of the fuselage facing towards the centre gangway, the glider towing attachment in the tail cone, the Behdix W.T. radio gear and the A.3 Auto Pilot. The Bendix Radio was not wanted because it was too bulky and would not be used in connection with Type "D" trials, and it was also intended to operate the Dakota without a wireless operator. The A.3 Auto Pilot was to be removed complete, including the Servo Motors which Were in series with the main control cables, so that no servicing of these components would be required under operating conditions ...[cont.].
Open Access
Crack formation in blanking and piercing
(College of Aeronautics, 1963-02) Noble, C. F.
In recent experiments on blanking and piercing, it was found that cracks occurred in the region of maximum hardness gradient and that cracking could be eliminated by radiusing the punch and die edges. In this paper, a simple stress analysis is made of the corresponding plane strain deformation, account being taken of the strain-hardening property of the work material. The above experimental observations are then shown to be compatible with the predicted stress distributions.