CoA. Memoranda

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1966 international toy fair Nuremberg 13 - 18 February
(College of Aeronautics, 1966-02) Smith, Charles E.
Nuremberg is a magic city. For one week each February this quaint but bustling place becomes an international wonderland. Not only is a fortune in toy business transacted but a very warm and human thing takes place. Visitors renew old associations and make new ones. Germans, Amercians, Britons, Poles, Belgians, French, Italians, Czechs, Swedes, Danes, Russians, Orientals, and others are involved in the largest display of toys in the world; and with each other, Peoples attitudes toward merchandise become stereotyped after a number of years in the toy business. But their attitudes and behavior toward their one time a year friends take on a new vitality each succeeding year. For American toy buyers the Nuremberg Spielwarenmesse (Toy Fair) offers a convenience of shopping not found elsewhere. The slick, high pressure salesmanship of New York is absent here. It is truly a buyers market. For the American toy manufacturer, Nuremberg affords 4 he opportunity to broaden his market and sources of supply as well as the chance to look for hew items, and even more important, new ideas. The exhibitions are held in five connecting buildings and there is an ample sprinkling of restaurants, snack bars, and vendors purveying the popular Nuremberg bratwurst. These are small sausages served with or without sauer- kraut and mustard. The buildings are well lit and well heated. This year these pleasant physical conditions were supplemented by unseasonably warm, clear weather.
Open Access
An abstract of a paper by D. Battat 'a new kinetic approach to the shock wave structure'
(College of Aeronautics, 1966)
Open Access
The aerodynamic characteristics of a family of related hovercraft shapes
(College of Aeronautics, 1967-09) Andrews, E. J.
The handling qualities of hovercraft indicate the need for a better understanding of the influence of the basic aerodynamic characteristics. This report is the first of a series in which the aerodynamic characteristics of hovercraft shapes are studied with particular reference to current design variables starting with simple solid block models and progressing to more sophisticated hollow models having cushion efflux and air-induction.
Open Access
An analogue method for the analysis of current carrying semiconductor systems
(College of Aeronautics, 1963-09) Loeb, H. W.
In an earlier Internal Technical Memorandum (1) and in subsequent work(2), it has been demonstrated that a particular kind of resistance network, in which non-linear elements are associated with each mesh point, can be made to represent an exact analogue to a non-degenerate semiconductor system in the equilibrium or quasi-equilibrium state. The term !exact' in this context implies that the difference equation which governs the potential distribution in the network becomes identical, for the limit of vanishing mesh interval, with the differential equation for the electrostatic potential within the semiconductor system, i.e. the Shockley-Poisson equation. From this type of analogue network information concerning the variation of maximum field intensity and of junction capacitance with applied bias voltages can be obtained for one, two and three dimensional configurations of p and n type regions of arbitrary geometry and impurity concentration profiles. One limitation to the applicability of the analogue technique arises from the restriction to quasi-equilibrium conditions. This restriction precludes the investigation of situations in which current flow contributions to the carrier concentration pattern become significant - for example, in the case of strongly forward biassed p-n junctions, and of p-i-n junctions and transistors operating at high injection levels. In the present paper, the problems involved in an extension of the basic analogue method to the treatment of non-equilibrium situations are examined, and means for their solution are discussed. A review of the methods previously described and an illustration of the nature of their limitations is given in Section 2. This is followed, in Sections 3 to 7, by a detailed treatment of the case of a current carrying semiconductor system in one dimension which leads to a theoretically possible realization in terms of resistancenetwork/ analogue computer techniques, which is, however, too complex to. be considered practical. Section 8 discusses means for the simplification of the proposed schemes and leads to the description of a relatively simple system in which a significant reduction in equipment complexity has been made possible by the adoption of an operating mode based upon an iterative process of successive approximations. The extension of the technique to three dimensions is outlined in Section 9.
Open Access
The analysis of the current shape in the circuit analogous to the a.c. welding circuit
(College of Aeronautics, 1967-08) Kuszleyko, Richard
The suitability for welding of manual metal arc welding transformers depends on the no-load voltage and on the electro-magnetic behaviour of the reactor. The latter is related to the curvature of the actual magnetization characteristic. The analysis aims at the quantitative establishment of that dependency. The fulfilling of the imposed task is performed through the approximate evaluation of the current waveforms in the two simplified welding circuits that have been designed with equal parameters except the data of the reactors. The reactors have diverse magnetic circuits and when altering the two extreme working duties of the transformers, a distinctive difference arises between both the changes (for both reactors) of the magnetization characteristic curvature. The evaluation is done with a specially elaborated numerical method. When considering the results the two transformers with nearly the same proportions of the current shape at one working duty, appear to have entirely different proportions at the other working duty.
Open Access
Anisotropic superplasticity
(College of Aeronautics, 1969-06) Naziri, H.; Pearce, R.
Anisotropy has already been mentioned in connexion with SP. Johnson et al (1) have shown that specimens of circular cross-section, machined from hot-rolled SP Zn/Al eutectic and eutectoid plate, become elliptical on straining in the rolling direction, while the fine-grain Zn/Al eutectoid produced by the quench-4 spinoidal decomposition method did not.
Open Access
An apparatus for the measurement of tensile creep and contraction ratios in small non-rigid specimens
(College of Aeronautics, 19) Darlington, M. W.; Saunders, D. W.
An apparatus is described for precise measurement of creep properties in specimens with gauge lengths down to 1.2 cm. An extensometer has been developed which is supported independently of the specimen and exerts a load on the specimen of less than 5 grams. It can thus be used with small non-rigid specimens. The extensometer will detect strains down to 2 x 10-6. The stability is excellent. An adaptation of the system which allows simultaneous measurement of tensile strain and lateral strain during creep is also described. The apparatus was designed for the measurement of anisotropy of creep properties in oriented thermoplastics and reference to such measurements is given. It is however entirely suitable for general application to small specimens.
Open Access
Application of inflated structures to hovercraft annual survey 1968-69: inflated structures report C1206/3
(College of Aeronautics, 1969-09) Richards, D. M.
1.0 Introduction This report surveys work carried out in the Department of Aircraft Design at the College of Aeronautics, Cranfield, in accordance with the terms of Ministry of Technology contract reference PD/28/045/ADM, College of Aeronautics reference 0.1206. The period covered by this report extends from 1st October 1968 to 1st October 1969, which constitutes the first complete year of operation under the contract terms. The reporting procedure agreed with Mintech is that individual research topics shall be separately reported in the form of technical memoranda, and that comprehensive surveys of a descriptive nature shall be submitted at regular intervals.
Open Access
The application of information theory to parcel sorting
(College of Aeronautics, 1969-02) Degerlund, B. R.; Pemberton, A. W.
The work on parcel sorting was originally suggested to the Materials Handling Research Unit by British Rail which is one of the sponsoring organisations contributing to the Research Fund. This work has also formed the subject of a research thesis, which has been used as the basis of this report. The student, Mr. B. R. Degerlund is therefore the main author, in co-operation with the staff of the Research Unit … [cont.].
Open Access
An appraisal of the Guttinger statistic 611
(College of Aeronautics, 1966)
Using the Systems Design procedure developed at Cranfield, an appraisal of the Guttinger Statistic 611 has been carried out; in particular, the interface of the machine has been redesigned.
Open Access
An assessment of a copper-containing drawing-quality steel sheet
(College of Aeronautics, 1967-10) Pearce, Roger
Open Access
An assessment of the critical strains which can be sustained by a mar-ageing steel under bi-axial tension
(College of Aeronautics, 1966) Pearce, Roger
Mar-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.
Open Access
Automatic assembly design project 1968/69: report of the control and motivation committee
(College of Aeronautics, 19) Wrigglesworth, D.; LeHunte, G.; Kimber, A.; Gray, A.
Methods of control for automatic assembly machines are surveyed. The control requirements of the versatile automatic assembly machine are analysed, and the most practical system is specified and designed in detail.
Open Access
Automatic assembly design project 1968/9 : Report of economic planning committee
(College of Aeronautics, 1969) Jones, P. V.; Pettitt, M. E.; Kaloo, U.
Investigations into automatic assembly systems have been carried out. The conclusions show the major features to be considered by a company operating the machine to assemble the contact block with regard to machine output and financial aspects. The machine system has been shown to be economically viable for use under suitable conditions, but the contact block is considered to be unsuitable for automatic assembly. Data for machine specification, reliability and maintenance has been provided.
Open Access
Automatic assembly design project 1968/9: report of assembly analysis and coordination committee
(College of Aeronautics, 1969) Shaw, C. R.
The present assembly method and component parts of a chosen product are analysed. The design of components is investigated, and a workstation sequence is proposed based upon the modified components. A pick-and-place head is designed, versatility being the main design criterion. A functional check mechanism is designed.
Open Access
Automatic assembly design project 1968/9: Report of component supply and separation committee
(College of Aeronautics, 1969) Gray, A. F.; Hayes, D. A.; Jones, P. V.; Scarr, A. J.
This report outlines the techniques for automatically feeding the components of an electrical contact block and describes the design of a feeding system for each component. All components of the contact block were initially analysed for automatic feeding and redesigned where necessary. Existing feeding methods were examined and consideration was given to their versatility. Decisions were then made as to the feeding system for each component.
Open Access
Automatic assembly design project 1968/9: report of technical survey committee
(College of Aeronautics, 19) LeHunte, G. G.; Stout, K. J.; Charnley, C. J.; Powell, E. A.
An Industrial survey has been carried out to determine the desired features of an automatic as machine. A questionnaire was circulated to industry and the results of the 38% response obtained were analysed and plotted. From these, conclusions were drawn as to the industrial requirements of an assembly machine.
Open Access
Automobile axle accelerations statistical analysis of field measurements
(College of Aeronautics, 19) Stayner, R. M.
Summary Accelerations produced at the stub-axles of a vehicle during passage over a road surface are a prominent source of vibrations of the vehicle. This memo describes the instrumentation of a motor car to record these accelerations, and the statistical analysis of records obtained, in terms of Amplitude Distribution, Power Spectral Density Function and Auto.. correlation Function. Cross-correlation functions between some of the acceleration signals are included and their salient features discussed, together with the utility of the other statistical descriptions. Sugr4estions are made for laboratory work to increase the information to be gained from such measurements and the generality with which it can be applied.
Open Access
C.V.D. annual report: November 1965 research project RU27-1 :an analogue method for the determination of potential distributions in semiconductor systems
(College of Aeronautics, 1965-11) Davis, J. A.; Loeb, H. W.
A general method for the solution of the nonlinear Shockley-Poisson differential equation which governs the potential distribution in non-degenerate semiconductor systems is described which can be applied to the evaluation of depletion layer widths, carrier densities and capacitance bias relationships of p-n junction structures. The method is based upon the use of a particular type of resistance network analogue and results obtained for several one and two dimensional configurations are discussed.
Open Access
C.V.D. annual report: January, 1967 research project ru27-1 : analogue study of semiconductor device structures
(College of Aeronautics, 1967-01) Andrew, R.; Loeb, H. W.
The e::tension of the resistance network analogue method to the study of a M.O.S.T. structure is described. By means of an iterative technique, data regarding channel current, field distribution, surface charge and position of pinch-off point as function of gate and drain voltagen can be obtained which do not involve the usual 'gradual' channel approximation Results for a particular device geometry are presented. A discussion of a digital computer approach to the solution of semiconductor device current flow problems is included, together with preliminary results.