bluuebunny/crossref_metadata_2025 huggingface dataset:
The Development of Inventions
Authors: Coombs T. A.
Published: October 2007

The lecture describes some of the problems of putting inventions into practical use, drawing largely on the author's experience in the National Research Development Corporation. The functions of NRDC in exploiting inventions and in supporting their development are described. Various sources of inventions—private individuals, public research, and industrial companies—are discussed with particular considerations which arise in each case. Methods of assessing research and development projects are described and the importance to be attached to the technical, management, and selling aspects is examined.

The lecture is illustrated by some of the unexpected incidents which can occur. Although the author is unable to make startling confidential revelations he takes examples from successful and unsuccessful NRDC projects. He attempts to draw some conclusions which may be of general interest to those associated with the many interesting aspects of innovation.
A New Computation Model of Combustion in the Spark-Ignition Engine
Authors: Annand W. J. D.
Published: October 2007

The paper presents an attempt to embody, in a calculation of the combustion and expansion phases of the working cycle of a spark-ignition engine, a representation of the observed fact that reaction is not completed in the flame front, but is continued in the enflamed gases. It is argued that the secondary reaction consists mainly in the transformation of excess carbon monoxide to dioxide, and crude representations of the formation of the excess and the rate of transformation are adopted. Results of computations made in this way conform with observation better than those made on the assumption of chemical equilibrium behind the flame front, and help to explain some experimental findings.
Spatial Variation of Heat Transfer to Pistons and Liners of Some Medium Speed Diesel Engines
Authors: Seale W. J. , Taylor D. H. C.
Published: October 2007

Heat transfer coefficients have been measured on the gas side of pistons and liners, the water side of liners, and the oil side of pistons. A significant radial variation in heat transfer across the piston crown has been found. The position of the maximum heat transfer coefficient appears to be coincident with the maximum air concentration, or the position the tips of the fuel sprays have reached at the time of ignition, and the radial variation of heat transfer is possibly related to the amount of fuel burnt at each radius. For four-stroke engines, equations are presented to describe this variation. Heat transfer coefficients at the exposed section of the liner have been found to be similar to the values at the outer edge of the piston.

Heat transfer between piston undercrown and cooling oil has been measured for various types of cooling arrangement and, for jet cooling, an expression has been suggested for the heat transfer coefficient.

Equations have also been derived to enable coefficients to be predicted for heat transfer from liner to cooling water.
The Use and Abuse of Materials in Ocean Engineering
Authors: Birchon D.
Published: October 2007

Almost every kind of material and fabrication process now has to be used to meet the demands of ocean engineering, ranging as it does from hydrofoils to research submersibles, and from giant tankers to offshore drilling rigs.

Some of the difficulties are obvious, for example when aircraft-like design procedures must be adopted for hovercraft to operate at sea; others, such as the vagaries of corrosion and the risks of brittle fracture, are more subtle.

This paper briefly reviews the history of the use of materials in ocean engineering and touches upon their impact on contemporary affairs; some present material capabilities and weaknesses are discussed, and the new philosophy of structural validation and some of the supporting techniques being introduced into the Navy are outlined. Some case histories of the use and abuse of materials in ocean engineering are also described and the paper closes with a glance to the future and some suggested golden rules which may help designers to minimize the abuse of materials.
Comparative Dynamic Acceptance Tests for Machine Tools Applied to Horizontal Milling Machines
Authors: Sadek M. M. , Tobias S. A.
Published: October 2007

The paper is concerned with the objective evaluation of performance improvements achieved in three successive stages of development of a horizontal milling machine.

It is proposed that the dynamic quality of machine tools be measured by the coefficient of merit (c.o.m.) of the structure under consideration. This is a measure of the chatter resistance of the machine, being proportional to the maximum width of cut which is stable at all cutting speeds. The c.o.m. is obtained with the aid of vibration tests. It is derived from the ‘operative receptance’ of the system as inversely proportional to its maximum negative in-phase amplitude.

After discussing the general basis of this type of acceptance test, the concepts are applied to the particular case of the evaluation of the relative performance of three successive stages of development of a horizontal milling machine. For this purpose the c.o.m. of the three machines are plotted as a function of the depth of cut, with the angle between the normal to the centre of the arc of contact and the representative cutting force as a parameter specifying tool design. These curves can be combined to show the relative improvement achieved in the second or third stages of development with respect to the former designs.

The predicted performance of the three machines is verified, for one particular value of the depth of cut, by determining experimentally the stability charts of a milling process carried out on each of them. Some indirect confirmation of the validity of the proposed method for assessing machine tool performance is given by investigating its consistency.
Cumulative Damage in Push-Pull Fatigue of Fillet-Welded Mild Steel Plate Subjected to Narrow Band Random Loading
Authors: White D. J. , Lewszuk J.
Published: October 2007

Push-pull fatigue tests have been made in constant amplitude loading and in narrow band random loading on fillet-welded cruciforms made from 3/8 in thick mild steel plate to B.S. 1501-151 Grade 28. The test frequency was 250 Hz, mean tensile stresses of 0, 5 and 10 tonf/in2were employed and tests were extended for endurances of up to 108cycles.

Curves have been fitted to the S-N results using the relationship N( S — So)α= C and on the assumption that this may be extrapolated beyond 108cycles, curves showing the effect of mean stress are given for both constant amplitude loading and narrow band random loading for endurances up to 1012cycles. Suitable factors of safety should be applied to these stresses before use in design. For endurances beyond 107cycles, an increase in tensile mean stress from 0 to 10 tonf/in2reduced the fatigue strength by about 50 per cent in both constant amplitude loading and random loading.

Reasonable agreement was found at all mean stresses between the experimental random loading S-N curves and those predicted using the constant amplitude results and the Palmgren-Miner cumulative damage hypothesis.
Second Paper: Observations of Ball to Track Contact Angles and Inclination of Ball Rolling Axis in an Angular Contact Ball Race
Authors: Haines D. J.
Published: October 2007

Discrepancies between predicted and actual ball race performance have drawn attention to the theoretical assumptions at present in use. This paper reports an experimental study of contact angle positions and ball rolling axis inclinations from which it is concluded that centrifugal track expansions should be included in predictions of contact angle positions, and as speed is increased the ball rolling axis moves out of the centreline plane of the bearing.
Fourth Paper: A New Design of Angular Contact Ball Race
Authors: Haines D. J. , Edmonds M. J.
Published: October 2007

The work reported in the second and third papers revealed that under high speed operating conditions significant slide occurs at the contact points. The full extent of the present limitations became apparent in 1967 and led in that year to the new race design. In this design the balls contact the outer track at two points simultaneously instead of the conventional one point.

An approximate analysis of race behaviour is presented which indicates that when the new bearing is driven from the inner track the ball motion is controlled at this track over most of the operating range. This fact and the retention of the inner, and the major outer contact positions, at points close to their static positions result in improvements in performance of up to 30 per cent at high speeds.
The Strength of Steel
Authors: Finniston H. M.
Published: October 2007

Understanding of the metallurgical factors which determine the strength characteristics of metals has progressed to the point where in principle steels can be tailor-made to meet specific engineering requirements. The lecture describes some of the basic features underlying the physical metallurgy of steels particularly in relation to differing stress situations, e.g. creep, fatigue, brittle-ductile failure, etc., and the quantification of the metallurgical parameters relating to deformation and fracture. Reference is made to the direction of future developments and the new experimental techniques which should contribute to these.
Grinding and Abrasive Wear
Authors: Buttery T. C. , Archard J. F.
Published: October 2007

To explore the relationship between grinding and abrasive wear, a range of differing experiments has been performed. These include simple wear tests, dynamometer measurements of grinding forces, simple scratch tests with both idealized indentors and abrasive grits, and the microscopic examination of abrasive wheels and worn surfaces of steel. It is suggested that grinding and abrasive wear should be regarded as essentially similar mechanisms. The anomalies which occur with heat-treated steels, of a range of hardness, in both grinding and abrasive wear may be attributable to the influence of ploughing which affects the efficiency of the action of individual grits.
Plane Strain Compression of Anisotropic Sheet Metal
Authors: Taghvaipour M. , Mellor P. B.
Published: October 2007

The plane strain compression of steel, aluminium, titanium and zinc sheet is investigated. Particular attention is paid to the lubrication of the dies and to methods of testing which eliminate creep. It is recommended that 0-001 in p.t.f.e. film is the most suitable form of lubrication, provided that the final thickness of the sheet is not less than 0025 in. To eliminate the possibility of creep in sheet materials, continuous testing in separate indentations is recommended.

The experimental results are correlated with Hill's theory of plastic anisotropy. Agreement is good for steel and aluminium, and for most engineering purposes satisfactory for titanium. The correlation for zinc is poor.
The Education of Professional Mechanical Engineers
Authors: Brown A.
Published: October 2007

The qualities required of a professional mechanical engineer are discussed. In the light of these qualities, the limitations and excess variation of university degree courses in the United Kingdom are considered. The somewhat limited part played by the Council of Engineering Institutions in the education of engineers is mentioned. The new sandwich scheme operating in the Department of Mechanical Engineering, The Queen's University of Belfast, is introduced and discussed along with the implications and advantages of such a scheme being operated in the rest of the United Kingdom.
Effect of Pins with Flats and Resin-Bonded Polytetrafluorethylene Coatings on the Fatigue Strength of Large Pinned Connections Made from Alloy Steel FV520B
Authors: White D. J.
Published: October 2007

Results are presented of fatigue tests made on large lugs 4·25 in wide, loaded by means of a 2-in diameter pin. The effect on fatigue strength of a thin layer of resin-bonded p.t.f.e. stuck to the bore of the lug was studied and a systematic investigation was made of flats milled opposite to one another on the pin. The size of the flat is described by the angle (±θ) subtended by the flat at the pin centre and values from zero to +40° were covered. Two conditions of mean stress were investigated, namely, pulsating or repeated tension and 15 tonf/in2mean tension.

Although resin-bonded p.t.f.e. coatings prolonged fatigue life, they did not offer a reliable means of improving fatigue strength. Pins with flats were found to be of great benefit and for ±40° flats, as compared with a round pin, the strength ratio in pulsating tension was 3·6 and, at 15 tonf/in2, mean tension was 2·9. The combination of mean stress and size of flat is of critical importance because the strength can be increased or decreased by the addition of flats to a round pin.
Effects of Tilt on the Performance of Hydrostatic Thrust Pads
Authors: Howarth R. B.
Published: October 2007

The majority of hydrostatic thrust bearings are designed on the assumption that the bearing surfaces are parallel but, with the possibility of manufacturing and assembly errors and structural deformations, this condition is rarely, if ever, achieved in practice. With the increasing demands being made in modern machinery, more detailed design information is required.

An experimental and theoretical investigation was carried out into the effects of tilt on the operation of circular hydrostatic thrust pads, the results of which show that, for static conditions, the characteristics of a tilted pad can be reliably predicted, assuming the lubricant to be isoviscous. With this information, a thrust pad can be designed to operate in any specified tilted configuration or can be incorporated in a rigorous structural design. In many applications, however, it may be difficult to specify the tilt and in such situations it is more useful for the designer to have some indication of how the operating conditions may be modified by tilt when the design is based on parallel surfaces. For a system which is supplied from a constant pressure source through a viscous external restrictor, the modified operating conditions can be predicted. The effect of tilt on the operating conditions depends on the pad geometry and design resistance ratio but significant changes may occur in mean pad clearance, required flow rate and static stiffness.

Although this investigation was limited to static conditions, the results are still valid for sliding conditions where the hydrodynamic effects are small compared with the hydrostatic contribution. The general effects of tilt observed with circular pads are indicative of what may be expected with pads of other geometries.
Cracking in Cast Iron Diesel Engine Cylinder Heads
Authors: Smith L. W. L. , Angus H. T. , Lamb A. D.
Published: October 2007

The nature and mechanism of cracking in cast iron diesel cylinder heads arising from the differential thermal strains which occur in service are reviewed.

The results of experimental work with test apparatus simulating the conditions in a cylinder head are presented, illustrating the importance of controlling the boiling conditions of the water at the cooling face of the flame deck.

It is concluded that cylinder head temperatures, and therefore the danger of cracking, can be successfully reduced by increasing the flow of cooling water over critical areas by some form of directed flow.
Transient Response of a Time-Optimized Hydraulic Servomechanism Operating under Cavitation Conditions
Authors: Nikiforuk P. N. , Wilson J. N. , Lepp R. M.
Published: October 2007

The transient response of a time-optimized hydraulic servomechanism operating under cavitation conditions is analysed in this paper. Factors included in the analysis, in addition to actuator cavitation, are: valve dynamics, valve hysteresis, oil compressibility, actuator leakage and non-linear load friction. After the basic equations have been derived, the transient response is determined graphically using a modification of the technique introduced by McCloy in which the load-friction curve is superimposed on the valve pressure-flow curves. On this plot the load trajectory is determined, step-by-step. The transient response of the system is then determined. Experimental verification of the analysis is included.
Second Paper: Instantaneous Heat Transfer Rates to the Cylinder Head Surface of a Small Compression-Ignition Engine
Authors: Annand W. J. D. , Ma T. H.
Published: October 2007

Measurements of instantaneous heat transfer rates from the working fluid to the cylinder head of a small open-chamber, four-stroke, compression-ignition engine have been made at five points on the surface, using a new form of thin-film thermocouple. These observations demonstrate that flux magnitude and the form of flux variation during the cycle depend greatly on local conditions. Some of the observed phenomena are explained qualitatively. Finally, some results are presented of an analysis of fluxes averaged over all five locations, in terms of the bulk mean properties of the working fluid. It is shown that some compensation for the non-steady nature of the situation may be given by adding to the usual type of quasi-steady relation a term involving the time derivative of the bulk mean temperature.
Performance of Inward Radial Flow Turbines under Unsteady Flow Conditions with Full and Partial Admission
Authors: Wallace F. J. , Miles J.
Published: October 2007

The paper describes the most recent work to be completed in the unsteady flow investigation on radial flow turbines, earlier unsteady flow work for single entry casings having been reported in (1)†and (2), and steady flow work for very high pressure ratios and multiple admission in (3). The present paper combines these analyses to give a coherent treatment of single and multiple admission.
The Growth of the Engineering Profession: Statistics and Conjecture
Authors: Kastner L. J.
Published: October 2007

The Engineering Profession in the developed countries has greatly increased in numerical strength in recent years but the future pattern is not clear and forecasts of manpower needs in industry are unreliable. Nevertheless, statistics indicate that the United States has, relative to the industrial population as a whole, a clear advantage in technological manpower in the Western World though Russia may, perhaps, be even stronger. The difficulty of evaluating the evidence is stressed. In the world as a whole international co-operation tends to reduce the inequalities of distribution but an enormous task lies before the developing countries which need to produce and retain many more engineers.
Effect of Additives on the Cetane Ratings of Diesel Fuels as Related to the Ignition Delays of Liquid Fuel Droplets Impinging on a Hot Surface
Authors: Satcunanathan S. , El Nesr M. S.
Published: October 2007

Results of an investigation show that the effects of additives on the ignition delays of liquid fuel droplets impinging on a hot surface correlate satisfactorily with their effects on the cetane ratings of diesel fuels. It is also shown that additives for diesel fuels may be divided into three categories according to their effects on the above mentioned ignition delays, viz. (1) those that reduce the ignition delay at all dosages, (2) those that reduce the ignition delay at small dosages but increase it at high dosage and (3) those that do not have any significant effect on the ignition delay.
Steam Turbine Failure at Hinkley Point ‘A’
Authors: Kalderon D.
Published: October 2007

The catastrophic failure of Hinkley Point ‘A’ unit No. 5 in September 1969 was the result of spontaneous brittle fracture of a shrunk-on ***l.p. turbine disc, initiated by stress-corrosion cracking in the crown of a keyway in the disc bore. Stress corrosion cracking of disc bores and keyways was also found on a number of other discs. The discs were made of 3 Cr-Mo steel and complied with normal acceptance standards, but due to temper embrittlement, their fracture toughness was low, and cracks only about 1/16 in deep in the concentrated stress field at the keyway crown were large enough to initiate brittle fracture. Investigation of the cause of the stress-corrosion cracking is being separately reported.
Investigation into the Consequences of the Failure of a Turbine-Generator at Hinkley Point ‘A’ Power Station
Authors: Gray J. L.
Published: October 2007

The further investigation was extensive and is continuing but the present account is limited to what throws light on the Hinkley Point ‘A’ incident and its immediate consequences. There were three main areas of investigation: (1) laboratory and on-site exploration of conditions for stress corrosion cracking of relevant steels; (2) a survey of all relevant rotors to explore the effects of applying a purely fracture mechanics approach in ignorance of the mechanism causing the initial crack or defect; (3) an examination of rotors withdrawn from machines of similar mechanical design and of properties deemed to be in the highest risk category.

Interim conclusions have been drawn. They suggest that in certain non-reheat turbines it is possible to generate high chemical concentrations in regions of high stress and thus to promote stress corrosion cracking. The rate of propagation of such cracks is sufficient to produce critical stress intensities in discs of low fracture toughness in a region of high stress concentration.
Failure of Helically Wound Cables in High Friction Environments
Authors: Mitchell L. A. , Woodall D.
Published: October 2007

An unusual failure mode has been observed in helically wound cables when operating in high temperature environments without organic lubricants. Surplus strand lengths accumulate at a point along the cable to prevent the cable passing over pulleys and on to a winch. This paper presents a theoretical explanation for this phenomenon which suggests means by which it may be prevented. Two of these methods have been tested and shown to be successful.
Problems in the Lubrication Systems of Turbomachinery
Authors: Fowle T. I.
Published: October 2007

The paper reviews the current situation on a number of problems arising in the lubrication systems of turbomachinery and gives examples from personal experiences. Aspects covered include: aeration and foaming of the oil, bearing corrosion, chemical stability, problems of contact between the oil and reactive gases such as ammonia, and system contamination. It is concluded that contamination is the most widespread and serious cause of problems, with local overheating being the next most important source of difficulties.
The Dynamic Characteristics of a Hydrostatic Transmission System
Authors: Bowns D. E. , Worton-Griffiths J.
Published: October 2007

The dynamic performance of a hydrostatic transmission with a variable delivery pump used for speed control is predicted using a simple mathematical model. The analysis is then extended to take into account the transmission slip and torque losses, and the prime mover droop by employing signal flow techniques. The results were compared with those from an extensive test programme employing electro-hydraulic test techniques carried out on a typical hydrostatic drive.

The signal flow analysis improved the prediction of the transmission dynamic performance, but it was found that errors of up to 40 per cent were occurring, as many of the loads employed could not be accurately represented by simple mathematical models. A vector approach was adopted, using measured load loci that provided a correlation of within 4 per cent of the experimentally measured response, by using a value of oil bulk modulus midway between the isothermal and isentropic tangent values.

Mean return line pressure, restricted boost system and flexible pipeline effects were investigated.
Analysis and Measurement of the Relative Movements between the Road Wheels of a Vehicle and the Road Surface
Authors: Butler D. M. , Ellis J. R.
Published: October 2007

A method of analysis of suspension performance has been developed and is supported by experimental evidence. The particular advantage of this analysis is that all the suspension characteristics of real suspensions are calculated for all possible positions of the suspensions in a manner which relates the wheel movements directly to the body motions. The roll centre concept is discarded, with the result that the wheel movements, and hence tyre forces, which were masked by the limitations of the roll centre assumptions, are now available for examination and inclusion in any vehicle study. This has resulted in the development of more realistic models of vehicle ride and handling including anti-dive attitudes and other phenomena.
Waviness and Roughness in Hydrodynamic Lubrication
Authors: Tønder K. , Christensen H.
Published: October 2007

An analysis of the effect of waviness on lubrication is presented. This analysis consists of direct solutions of the Reynolds equation for corrugated slider bearings under various conditions. It is shown how the corrugation wavelength is a major factor, pressure ripples vanishing with increasing corrugation density. It is further shown that at the same time, the load-carrying capacity tends towards that predicted by the authors' statistical roughness theory, the analysis thus constituting a numerical proof of the mathematical soundness of that theory.
Analysis of Some of the Reference Lines Used for Measuring Surface Roughness
Authors: Radhakrishnan V.
Published: October 2007

Surface profiles are evaluated for their roughness with reference to a line that takes the shape of the waviness present. Such reference lines are taken either mechanically or electrically by the measuring instruments themselves. For a graphical construction of the reference line, a geometrical procedure is recommended in the standards. These reference lines, which are obtained either mechanically, electrically or geometrically, are analysed to find how far they represent the waviness present and their ability to separate it. Theoretical and practical results are compared.
Film Recession in Hydrostatic Thrust Bearings
Authors: Newton M. J. , Howarth R. B.
Published: October 2007

In general, hydrostatic thrust bearings are designed to operate with parallel bearing surfaces and it is assumed that the lubricant film completely fills the bearing clearance. In practice, bearings almost inevitably operate in a tilted condition and this modifies the behaviour of the bearing. In addition, when the surface approaching the bearing under sliding conditions is free of lubricant, recession of the film boundary can occur which further modifies the bearing characteristics.

An experimental and theoretical investigation has been undertaken into the behaviour of tilted and parallel hydrostatic thrust pads operating under ‘dry’ sliding conditions. It has been shown that recession of the lubricant film can occur under quite modest operating conditions and that this results in a substantial modification of the bearing characteristics whether the bearing is parallel or tilted. Another feature of film recession revealed by the investigation is that it eliminates the occurrence of cavitation in the film. Boundary recession greatly complicates prediction of the bearing characteristics, but it is shown that this can be carried out successfully giving predicted characteristics that are in reasonable agreement with the experimental data.
Parameters for Correlation of Penetration Results for Diesel Fuel Sprays
Authors: Williams T. J.
Published: October 2007

Existing empirical data has been employed to produce a dimensionally consistent penetration correlation for diesel fuel sprays. It is shown that the result is capable of physical interpretation and may be employed in penetration models which allow for effects not included in the experiments from which the data were gathered. The interpretation leads to suggestions for the type of result required from further penetration experiments.
The Diesel Engine to Compete with the Gas Turbine in the Large Commercial Vehicle Field
Authors: Broome D.
Published: October 2007

The interest in gas turbines as power plants for future heavy commercial vehicles has promoted a general study of power plant requirements for this application over the next decade, including likely demand and power levels. With this as a guide, trends in the development of the diesel engine are examined, and predictions made of speeds, mean brake effective pressures and configurations which might result. Some areas of technical interest are discussed. It is concluded that the diesel will continue to meet operator requirements in the period considered, and will remain fully competitive with alternatives.
Combined Forced and Free Convection Laminar Flow over a Vertical Plate
Authors: Brown A.
Published: October 2007

The approximate integral method of von Kármán is adapted to analyse combined forced and free convection laminar flow over a vertical flat plate at a constant temperature. This approach produces relatively simple expressions relating velocity and temperature profiles, skin friction and heat transfer to Pr and Gr/Re2 for the situation where forced convection flow is dominant over free convection. The results of the analysis compare favourably with more exact theoretical treatments and with experiment.
Prediction of Flow and Heat Transfer in Ducts of Square Cross-Section
Authors: Launder B. E. , Ying W. M.
Published: October 2007

Numerical predictions are presented of the hydrodynamic and heat transfer characteristics of fully developed turbulent flow in square-sectioned ducts.

The turbo stresses in the plane of the cross-section, whose gradients cause the well-known secondary motion, are approximated by gradients in the axial mean velocity.

Predicted results are in close agreement with available experimental data of primary and secondary velocities as well as the shear stress and heat flux variations around the perimeter.
A Review of the Operational Behaviour and Design of Direct Contact Feed Water Heating Plants for Large Thermal Power Stations
Authors: Dartnell Lawrence
Published: October 2007

Condensate heated by direct exposure to bled steam in pressure vessels gravitates through heaters in cascade and is transferred by pumps to the next cascade or to the deaerator-storage tank.

Direct contact heaters are proved to be thermally effective but the systems in which they are incorporated are shown by operational experience, by review and by analysis to need careful and detailed design for trouble-free operation.

Operational experiences are described together with predicted modes of behaviour of the cascades when subjected to extreme conditions of operation and to fault conditions.
A Contribution to the Study of Analogies of Power Transmissions in Machines
Authors: Schlösser W. M. J.
Published: October 2007

In this lecture an analogy is described by means of which transmissions can be analysed and compared. Two important design parameters are the force density Δ and the effective volume V*, which can be used to analyse stationary and moving methods of transmission.

With this analogy a tool is given to the designer to compare transmissions with regard to performance, controllability, size and weight, intensity of loading, dynamic properties. A beginning has been made with formulating a relation between the intensity of loading and wear phenomena (II).

With this work we hope to have contributed to a sounder basis for the study and development of power transmissions and their use in machines. As mechanical, electrical, pneumatic, and hydraulic power transmissions can be compared by means of this analogy, the selection of transmissions can be made on a sounder basis.
Offshore Oil and Gas: The Future Engineering Contribution
Authors: Allcock L. C.
Published: October 2007

Development of offshore oil and gas production from the continental shelf and in even deeper water will be dependent on engineers. It is of primary importance to understand the nature of the oil and gas production industry in order to follow more clearly the contribution that will be required from many of the professional branches of engineering, and a great deal of new technology must be developed in order that the problems of the future may be overcome. The difficulty may not be in defining the future engineering of oil and gas development but in finding engineers in sufficient numbers to meet the demand.
Turbocharging of Small Engines
Authors: Goodlet I. W.
Published: October 2007

During the last 20 years, progressively smaller diesel engines have been turbocharged, so that units of 50-60 hp are produced today. Spark-ignition engines remain normally aspirated for most applications, although this picture may change.

Progress followed the adoption of radial flow turbines using lost-wax cast rotors. Other developments included:raising component efficiencies; dealing with bearing and seal design problems, and with vane vibration; and in devising manufacturing methods for quantities approaching 3000 weekly, in mixed and rapidly changing batch sizes.

Various control systems are available to match the turbocharger to the demands of variable speed engines.
Technological Developments in the Iron and Steel Industry—a European View
Authors: Petrick J. W.
Published: October 2007

Developments within the European Coal and Steel Community, since it was founded in 1952, are outlined. Particular attention is devoted both to the technical research that has been carried out under the E.C.S.C. cooperative research progamme and to the impact that technological change has had on the industry. An attempt is made to link the advances in technology and production with economic considerations. The lecture will discuss current trends in the availability of raw materials and energy and their influence on steel production. The future prospects of the iron and steel industry within the enlarged European Community are considered and the likely directions of technological advance are discussed.
An Advanced High-Speed Dynamometer for Testing Aircraft Tyres, Wheels and Brakes
Authors: Roberts J. B.
Published: October 2007

Unlike tyres, wheels and brakes for commercial vehicles which can be tested on the road as a major part of their development programme, such equipment for aircraft must be qualified to full service conditions in the laboratory before being fitted to an aircraft.

This paper covers the specification background, design features and construction of a large, high-speed dynamometer on which the development and qualification of aircraft tyres, wheels and brakes are carried out. Particular attention is given to several fundamental advances in design including the electrical stimulation of brake inertia, computer control and monitoring of the main systems and the real-time recording of tyre forces in three planes.

The paper covers a combination of the mechanical, electrical and instrumentation engineering content of the facility.
The Training Needs of the Profession for the Next Decade
Authors: Shaw F.
Published: October 2007

The main theme of this Address is the training of professional engineers, although it is apparent that training cannot be completely divorced from education. Primary education is dealt with briefly, but sufficiently to indicate its importance. A proposal is made for a system of mentor and tutorial guidance extending from the sixth form through the industrial student stage, and through University to Corporate Membership of C.E.I. and into management.

At each stage of development the responsibilities of the various participants are clearly outlined, and proposals are made for training and educational programmes. These are broad enough to be applicable to almost any discipline, and should be tailored to suit the individual requirements of any organization. The Address is concerned with the methods which should be adopted for manager development, not only for the graduate but right through, as a continuing process, for all grades of management.
Second Paper: Application to the Channel Tunnel of a Method of Calculating the Transient Flows in Complex Tunnel Systems
Authors: Henson D. A. , Fox J. A.
Published: October 2007

The method of calculating the aerodynamic flows and pressure transients described in the first paper was used to make predictions for the Channel Tunnel. Results for single trains and for two-way working are shown. Some of the important parameters of the tunnels and trains were varied to show the effects of such changes so that the design could be checked and refined from the aerodynamic standpoint.
Achieving Quality and Reliability
Authors: Carter A. D. S.
Published: October 2007

This paper is a subjective summary of nine conferences on quality and reliability organized by the Institution of Mechanical Engineers during the last decade. Starting from economic factors, optimum design is identified with minimum total life cost, which is, in turn, closely related to reliability. The paper examines reliability theory briefly for its practical implications, e.g. that reliability depends crucially on safety margin and loading roughness. The former is a design feature, but both are operator controlled. The matching of design to the requirements of the user in the intended environment is considered paramount. It is shown that reliability is so dependent on such factors that design for prescribed levels of reliability presents formidable difficulties. The design process is discussed, taking these and maintenance constraints into account. The necessity for proper development is underlined. It is noted how realistic theory supports everyday practical experience. Finally, the function of management is discussed.
Experimental Evaluation of a Streamline-Curvature Method for Flared Subsonic Cascades and for Transonic Cascades
Authors: Bindon J. P. , Day I. J.
Published: October 2007

The accuracy of the streamline-curvature method has hitherto not been evaluated for curved-axis convergent-divergent flow as found in transonic turbine cascades and for flow in cascades with flow divergence or flare. To provide the data for evaluation, two simple single-channel rectangular-section wind tunnels were built to simulate the flow between turbine blades. The supersonic channel was successfully and economically powered by a large steam ejector.

In transonic and supersonic flow, an examination of the sonic and M = 1·1 lines was used as a basis for evaluating the predictions. The correlation was found to be good near the convex surface, but showed a deterioration towards the concave surface. Both test and prediction revealed the unexpected fact that the sonic line contour is not smooth, but wavy. The correlation at the M = 1·1 line was positionally the same as the sonic line, but the experimental contour was considerably more wavy. The accuracy deteriorated further into the supersonic region. The discrepancies in the transonic region are thought to be caused by a very slow rate of change of area, which produces a complex boundary layer interaction in the throat region, affecting both the location of the throat and the area ratios in that zone.

The prediction method was shown to be extremely accurate for flared-cascade flow even up to the very exacting situation of a 40 per cent blade height increase, the only error being that due to boundary layers in the apparatus that effect the velocity distribution over the latter half of the suction surface in a highly staggered cascade.
Longitudinal Water-Level Variations in the Drums of High-Pressure Circulation Boilers
Authors: Crow I. G.
Published: October 2007

Factors influencing the longitudinal variation of water level in the drums of circulating boilers are discussed with reference to the results of cold-circulation trials performed on a 500 MW assisted-circulation boiler. Numerical computation and small-scale model tests in support of the field trials are also presented. This information, together with evidence from further work on the operating boiler, has shown that small cold-water models provide an accurate analogue of drum operation at working pressures and temperatures.
Second Paper: Comparison between Measured and Calculated Thicknesses of the Oil-Film Lubricating Piston Rings
Authors: Hamilton G. M. , Moore S. L.
Published: October 2007

An iterative method of solving the hydrodynamic equations of lubrication of a piston ring is described. Some results of the calculations are compared with the measured values of the oil-film thickness in an actual engine. It is shown that there are disagreements of up to a factor of 8 between the theoretical and measured values. Further experiments were carried out on a single ring in a motored rig and here it was shown that although the film thickness is considerably greater, it is still not in complete agreement with the theory.
Air Motion in a Four-Stroke Direct Injection Diesel Engine
Authors: Dent J. C. , Derham J. A.
Published: October 2007

This paper presents the results of a study of the air motion in a motored four-stroke direct injection diesel engine using hot-wire anemometry.

The effects of engine speed, valve masking and supercharging on mean air swirl have been studied. A theoretical analysis is developed for the mean air swirl which in general shows good agreement with the experiments reported here and with the measurements of other workers on similarly sized engines.

The problem of ‘squish’ has been investigated and it is shown to be the radial component of the spiralling swirl flow entering the combustion chamber. Reasonable agreement has been found between measurement of the radial flow component at the edge of the combustion bowl and a theoretical analysis that considers the bulk radial flow of air to the combustion bowl during the last 30°-40° b.t.d.c. of the compression period.
Commercial-Vehicle Cabs: Design for Packaging, Access and Visibility
Authors: Hemmings K. R.
Published: October 2007

The contents of this paper were originally prepared for a contribution to a conference on ‘Design of commercial vehicle cabs in relation to the driver's environment’, held on 26th April 1973. The information contained in the address by the author was considered of general interest and value to the commercial-vehicle industry. The paper is aimed at providing guidance in the derivation of commercial-vehicle cab design with particular reference to packaging, accessibility and visibility. Certain conflicting requirements, design problems and solutions are discussed and the author's observations on some of the possible future trends in cab design are included.
Kinematic Synthesis of Spatial Path-Generating Mechanisms
Authors: Osman M. O. M. , Mueller G. S.
Published: October 2007

A design technique for coupler curve generating mechanisms is developed. The procedure is based on a multi-variable search using an objective function developed from topological properties of spatial curves in an arbitrary reference system. The method completely specifies the mechanism and its orientation relative to the chosen co-ordinate system, which generates the best approximation to the desired curve. The procedure always converges from any set of starting conditions. The technique is well suited to digital computer design of planar and spatial mechanisms, as it permits both the synthesis and the kinematic analysis of the mechanism. The 4R and the RGCR four-bar spatial linkages with coupler points are used to illustrate the synthesis procedure.
Slip Factor of a Centrifugal Compressor and Its Variation with Flow Rate
Authors: Whitfield A.
Published: October 2007

To predict the complete performance map of turbocharger centrifugal compressors, it has been found essential to include a procedure for estimating the slip factor at off-design flow rates. The many correlations available for the slip factor only concern themselves with design-point operation and consequently only provide a single value for the slip factor. The approach presented here attempts, within the confines of a one-dimensional procedure, to recognize the changing flow pattern at the impeller discharge in order to predict the variation of slip factor with flow rate. The procedure is based upon the well-established jet-wake flow model of Dean and the overall slip factor calculated from the jet slip factor.

Experimental and theoretical slip factors are presented for three impellers with 34, 30 and 12 radial blades, respectively. The complete performance map of the 12-bladed turbocharger compressor and the effect of using a constant and varying slip factor on the predicted performance are presented.
First Paper: Effects of Simplifying Kinetic Assumptions in Calculating Nitric Oxide Formation in Spark-Ignition Engines
Authors: Annand W. J. D.
Published: October 2007

The amount of NO (nitric oxide) developed during the combustion and expansion phases of the spark-ignition engine cycle has been calculated using several different kinetic formulations, for a range of fuel-air ratios at each of two compression ratios. Comparing the results shows the effects of including or omitting certain reactions and of applying the quasi-stationary assumption to the concentrations of N and N2O.
Nitric Oxide Formation in Diesel Engines
Authors: Çakir H.
Published: October 2007

A combustion model is presented to account for the nitric oxide formation in diesel engines at all operating conditions. The paper tries to introduce the concept of variable air-fuel ratio estimated to exist during diesel combustion. Analytical solutions are found to be in good agreement with experimental results. Further investigations will be directed to diesel engines having combustion systems other than the M.A.N.-FM system, and to possible remedies to reduce the formation of nitrogen oxides.
Human Environmental Requirements—A Basis for Developing Products in the Heating and Ventilating Industries
Authors: Ryd Harriet
Published: October 2007

The accelerating rate of energy consumption and increasing environmental damage appear at present to be two unavoidable consequences of measures taken in the course of development planning.

One of the explanations for this is that the essential climatic function of a building development—that of modifying the natural climate so that it is favourable for man—is not borne in mind in all stages of the planning process. Hitherto, the effects of locating a polluting works on the regional climate have been disregarded. Little account has been taken of the way in which distributing green spaces and formulating town blocks affects the climate of urban areas. Insufficient attention is paid to the way in which the orientation and design of an individual building and the surrounding vegetation will influence the climate in the outdoor areas around the building. Sometimes, calculations are made of the changes between the outdoor and indoor heat climates that would occur as a result of the particular construction and material composition employed on the building, but these are used primarily as a means of defining the initial conditions for climatic control installations and not for determining the joint climatic properties of the building.

Another explanation of this uneconomic climatic planning is that the aim of climatic modification has been incorrectly formulated. Hitherto, endeavours have been made to create an indoor climate that keeps the physical environment of man in a static condition. This condition has been termed the ‘comfort climate’. This has been defined as those values of the elements of the physical environment that deliver neutral information to the sensory organs. If one wishes to be controversial, one can say that the aim of climatic planning has been to create a ‘comfort climate’, which effectively prevents man from receiving stimulating information from his surroundings. More economical climatic planning calls for a definition of the ideal climate to suit the way in which people function.

This paper discusses the need to define human environmental requirements as a basis for more conscious cooperation between planners, architects and engineers as well as a basis for developing products in the heating and ventilating industries.