bluuebunny/crossref_metadata_2025_split huggingface dataset:
Some Experiments on Packed-Bed Drying
Authors: Oliver D. R. , Clarke D. L. 
Published: October 2007

Drying equipment is described in which streams of air of accurately-controlled temperature and humidity may be passed over the surface of a packed bed. The materials used in the beds are sieved spherical particles of copper, glass and polystyrene whilst the liquids are water, methanol and a series of organic solvents. Experiments are described in which the effect of physical variables on drying rate is measured. Surface tension is shown to have a major effect on the shape of drying rate curves; under the experimental conditions water is the only liquid for which the rate of drying during the constant-rate period is equal to that from a free liquid surface. The equivalent period for liquids of lower surface tension corresponds to a distinctly lower drying rate. Possible reasons for this behaviour are discussed. An increase in liquid viscosity causes reduction in drying rate, but only when the rate of drying is itself high. The effect of using solids of differing thermal conductivities is investigated. At high drying rates, increasing thermal conductivity produces increasing drying rate. Surprisingly a mixed bed (e.g. of copper and glass) often dries faster than beds of the constituent materials alone. Split beds are also used (beds of which the halves are of different materials). For these beds it is possible to observe the growth of dry patches on the surface of the beds and the manner in which liquid appears to migrate across the interface between the particles of the two halves. The temperature distribution across the interface is shown to be abnormal in part of the drying cycle. A conclusion which may be drawn from the work is that it is often an advantage, from the drying standpoint, to have particles that have either a wide range of thermal conductivities or a wide range of particle sizes.
Heat and Mass Transfer during Contact Drying in a Laundry Calender
Authors: MacLaren J. F. T. , Nicol A. A. , Wallace R. 
Published: October 2007

Contact drying of fabric was studied using a two-roll steam-heated laundry calender. The effects on heat and mass transfer of steam temperature, fabric initial moisture content, fabric velocity, contact pressure and steam-side heat transfer coefficient were observed experimentally. Bed and roller surface temperature profiles were measured to assist in interpreting and subsequently analysing the drying process. The experimental results were correlated using dimensionless parameters derived from a dimensional analysis of a drying equation. An empirical expression was obtained that related the final moisture content of the fabric to the initial moisture content and the other pertinent physical variables.
Trial by Organization and Ordeal: An Engineer's Search for Quality
Authors: Alden J. H. 
Published: October 2007

This paper covers two subjects of great interest to the writer: the organization of a design and development team and the operation of a controlled and audited test programme; the ultimate aim being quality and reliability of the product. The design and development team headed by the Chief Product Engineer should have four major ‘components’ reporting to him: the Project Manager, the Chief Designer, the Test Engineer, and the Tooling Control Manager. Their individual functions are discussed in the paper. Life testing of various components and the building of sufficient prototypes to prove the practicability of the product can all be achieved ‘on the premises’ by means of various rigs as described, but the real evidence of the success of the product can only be achieved by many thousands of miles of actual running on the most expensive test requirement of all, a modern well equipped proving ground, the many necessities of which are discussed.
Matching of High Output Diesel Engines with Associated Turbomachinery: First Paper: A General Approach to the Computer Solution of Single- and Two-Stage Turbocharged Diesel Engine Matching
Authors: Wallace F. J. , Cave P. R. 
Published: October 2007

The first paper describes the general approach adopted in the solution of steady-state matching of single-stage turbocharged engines with fixed and variable geometry turbines and two-stage turbocharged engines developed from general principles first reported in (1). Individual components are represented either by systems of equations or by multi-dimensional numerical arrays embodied in separate subroutines which are called from a main-linking programme containing the overall matching equations. Appropriate iterative procedures from initially assumed values of boost and turbocharger speed (for single- or two-stage arrangements) are briefly described. The programmes have been run both in batch processing and interactive mode, and in the latter form have been found particularly valuable as teaching aids.
Second Paper: Differential Compound Engine
Authors: Wallace F. J. 
Published: October 2007

The second paper assesses the overall performance characteristics of the differential compound engine (d.c.e.) first reported in (21), designed to constitute an integrated engine-transmission system providing high unit output, combined with outstanding torque characteristics for traction applications. Experimental results, for both equilibrium conditions and transient response are presented for the original two-stroke c.i. version of the laboratory unit, incorporating the Rootes TS 3 opposed piston engine. Theoretical predictions both for this version, and the later four-stroke version, using the Perkins 6·354 engine, based on the generalized computer approach of the first paper, are also presented. The unit is then critically compared with existing or prospective traction prime movers using the following criteria. (1) Fuel economy. (2) Torque characteristics. (3) Noise and emission. (4) Unit specific weight and bulk. Finally, a projected automotive unit of approximately 2 hp shaft output is described with illustrations to show the potential of the d.c.e. as an alternative engine-transmission system for heavy trucks and off-highway vehicles.
Maintenance Policy for Sugar Refinery Centrifuges
Authors: Jardine A. K. S. , Kirkham A. C. J. 
Published: October 2007

The results of a study to determine the optimal policy (defined as that which minimizes downtime) for the maintenance of continuous process centrifuge machines used in a sugar refinery are reported. It was identified that the machines could ‘fail’ as a result of any one of 34 reasons, 16 being mechanical faults and 18 electrical. Sufficient data were available to enable the six faults that caused most of the unscheduled downtime to be analysed quantitatively and an optimal maintenance policy to be identified. The problem was analysed by constructing a mathematical model of the situation, identifying the failure distributions of the components of the centrifuge that caused the six faults using Weibull probability paper and then using these data to solve the model. The optimal policy was identified to be breakdown maintenance.
The Accountant—Overhead Burden or Service?
Authors: Fea W. W. 
Published: October 2007

Both engineers and accountants working in industry are experts in measurement. The engineer expresses his quantitative data in physical units; the accountant evaluates quantitative measurements into financial terms. Planning the future and controlling the present are two principal functions of management. Accounting provides the common language of communication between the different levels of management planning and controlling all activities of the business. Cash flow, accounting for inflation, investment timing are important areas for the exercise of accountants' specialized training and outlook. The lecturer then outlines an actual comprehensive accounting information system operating in a large and successful engineering company. This illustrates his conclusion that while the engineer is the customer of the accountant providing information, they are partners in optimizing its use in running a business.
Condensation on the Surface of a Low-Pressure Steam Turbine Suction Blade
Authors: Ryley D. J. , Patel P. D. 
Published: October 2007

A 2·54 cm length of low-pressure turbine suction blade mounted between perspex walls to form a test section was used to determine the distribution of static pressure and surface temperature when passing near-saturated live steam at realistic turbine conditions. The distribution of static pressure conformed closely to that applicable to one-dimensional isentropic expansion with γ = 1·326. Working surface temperatures were taken for ‘steam-only’ flow with and without blade suction and for ‘steam-with-surface-water’ flow with and without suction. For dry flow with no suction, recovered values of temperature approximated to stagnation values, but with suction applied, a temperature reduction was promoted by the inward heat transfer due to the colder blade interior. Liquid film thickness was measured by electrical conductivity probes and values obtained were compared with predictions from turbulent film flow theories. Condensation on the blade surface was measured by three experimental methods and the results compared with predictions from turbulent-film condensation theories. A correlating equation is proposed which enables prediction of condensation rates from the average values of the steam Mach number and Reynolds number over the blade, and the Prandtl number of the water.
A Study of Two-Dimensional Supersonic Air Ejector Systems
Authors: Benson R. S. , Eustace V. A. 
Published: October 2007

The performance and flow field characteristics for two-dimensional ejector systems are determined theoretically for the condition when operation is independent of ambient pressure. The method considers the detailed inviscid interaction between the primary and secondary streams within the mixing tube and an estimate is made of the secondary flow entrained by the two-stream viscous mixing region. The validity of the theory is tested by comparing the performance characteristics of an experimental ejector facility with theoretical predictions and by comparing the theoretical flow field, in terms of constant density contours, with infinite fringe interferograms.
A Theory for Fatigue Failure under Multiaxial Stress-Strain Conditions
Authors: Brown M. W. , Miller K. J. 
Published: October 2007

A new theory for multiaxial fatigue is presented that is based on a physical interpretation of the mechanisms of fatigue crack growth. It may be represented graphically by contours of constant life, which are expressed mathematically by where ε1, ε2 and ε3 are the principal strains, •ε1 ≥ ε2 ≥ ε3. This equation underlines the importance of strain parameters in correlating fatigue data. It illustrates the effect of both the shear strain and the tensile strain normal to the plane of maximum shear. The theory is compared with several classical and recent theories, which are briefly reviewed. It is shown that classical theories of fatigue failure cannot correlate experimental data, and may be dangerous if used for design purposes.
The Contribution of Tribology to the Development and Operation of Railways
Authors: Barwell F. T. 
Published: October 2007

The contribution of the railway pioneers to the development and practice of tribology is reviewed, and it is contended that the engineers who had learned their craft on the steam locomotive were well equipped to tackle the sometimes more exacting tribological requirements occasioned by railway modernization. Steam cylinder lubrication is instanced as an example of the importance of ‘off design’ considerations and of the contribution, either helpful or unhelpful, made by those responsible for the operation of equipment. The numerous locations within a modern electrified railway wherein surfaces interact in relative motion are listed and discussed from the point of view of reduction in maintenance and enhancement of reliability. In particular, recent work on adhesion between wheel and rail is reviewed.
A Theory and Evaluation of Tool-Electrode Shape Degeneration in Electro-Discharge Machining
Authors: Crookall J. R. , Moncrieff A. J. R. 
Published: October 2007

An analytical approach is presented which provides the basis of the numerical analysis method for computation of tool-electrode shape degeneration in electro-discharge machining (e.d.m.). Following earlier work, the concept of ‘relative duty’ of the electrodes is utilized, and is found to predict the type, and to a less satisfactory degree the extent, of degeneration. Further experimental work confirms that the effect of local profile curvature on the local tool/work erosion ratio is greater than that suggested by the geometrical ‘relative duty’ concept. Subsequent incorporation of the empirical results of these tests into the numerical analysis brings the predicted shape degeneration behaviour into quite close agreement with experiment. Computed electrode profiles showing degeneration at different periods of elapsed sparking time are presented, together with the experimentally observed cases for comparison.
Safer Braking Systems
Authors: Ingram B. , Oppenheimer P. 
Published: October 2007

This paper examines some of the problems involved in engineering safer braking systems which will be appropriate for modern road vehicles and traffic conditions. 2AH. Braking systems are becoming more complicated, mainly because of the influence of international regulations, but also to take account of technical improvements in performance, which can be achieved with advanced forms of control systems, including anti-locking brakes. The need to ensure maximum safety is emphasized; despite the increasing complexity and despite a shortage of accident know-how, increased road safety must always remain the ultimate objective.
Some Aerodynamic Aspects of Safety in Road Vehicles: First Paper: Aerodynamic Lift Characteristics of Cars
Authors: Carr G. W. 
Published: October 2007

The principal factors determining the aerodynamic lift of cars are identified from the results of an extensive series of wind-tunnel tests involving simple models of bluff and streamlined form and a variable-geometry saloon-car model. The influence is examined of basic parameters such as camber, incidence, thickness, ground clearance, and underbody roughness. An indication is also given of the extent to which the lift is modified by the squaring of individual edges, particularly the horizontal leading and trailing edges; and the effectiveness of devices fitted under the nose of a car to reduce lift is discussed.
Fan Performance Testing Using Inlet Measuring Methods
Authors: Whitaker J. 
Published: October 2007

To contend with installation variants the fan must be tested in a system that resembles its site installation. Four simplified system arrangements are covered with two inlet test methods—ducted inlet and free inlet—by adding ducts to the free discharge. With free inlet tests a plenum chamber is attached to the fan inlet in order to obtain the required measurements; investigations to provide information concerning the optimum configuration of this test method are described. Determination of static pressure, selection of inlet devices for flow measurement; simulation of inlet and outlet ducts and the method of loading are also discussed.
Thermal Loading of a Petrol Engine
Authors: French C. C. J. , Atkins K. A. 
Published: October 2007

This paper reports the results of an investigation into the thermal loading of a modern 1·975 1, four-cylinder petrol engine operating at engine speeds of up to 100 rev/s. The effects of engine speed and load, mixture strength, ignition advance, compression ratio, coolant temperature and pressure, antifreeze, detonation, olefin content of fuel, and a piston modification on the local heat fluxes and metal temperatures have been determined and the maximum levels established. The methods of temperature measurement were fixed and traversing thermocouples for the cylinder head and liner, fixed thermocouples for the valve seats and spark plug, disappearing-filament optimal pyrometer and hardness recovery for the exhaust valve, differential thermocouples for the gross heat losses, and intermittent-contact fixed thermocouples for the piston. The greatest heat fluxes occurred at the centre of the combustion chamber, in the valve bridge and exhaust-valve seat region, and decreased towards the outside of the combustion chamber and down the cylinder liner. For the form of combustion chamber investigated the heat flux varied as the 0·6 power of the gross fuel consumption and the operating variables generally gave only second-order effects. The piston temperature is fairly sensitive to ignition advance, compression ratio, and high-speed detonation.
Pulse Converters—A Method of Improving the Performance of the Turbocharged Diesel Engine
Authors: Janota M. S. , Watson N. 
Published: October 2007

Today, most turbocharged diesel engines operate on the pulse system. This is most effective on those engines whose exhaust manifolds can connect groups of three cylinders to a turbine entry without scavenging interference, e.g. three-, six-, nine- and twelve-cylinder engines. However, when only two cylinders can be connected to each turbine entry, e.g. four-, eight- and sixteen-cylinder engines, without interference, the system is usually less efficient. This is because the widely fluctuating, partial admission turbine conditions lower the average turbine efficiency. Recently, the pulse converter has been developed to improve the performance of such engines. A detailed investigation into the operation and application of the pulse converter has been conducted. Test results from three completely different types of engines showed substantial improvements in performance. The dependence of the pulse converter on engine speed and load, the effect of area variations in the pulse converter and the timing of the interfering exhaust pressure waves have been studied. A comparison of theoretically predicted and measured transient pressures (from a model pulse converter fitted to a pulse generator) was made. The theoretical analysis is based on empirical steady-flow loss coefficients and forms a boundary condition for a method of characteristics analysis. Results are compared with those predicted by the simple constant-pressure theory.
Design of Pump Impellers for Optimum Cavitation Performance
Authors: Pearsall I. S. 
Published: October 2007

Although there is much empirical information on the cavitation performance of centrifugal and other types of pumps, there is very little theoretical basis for their design. Certainly these empirical data have been used to suggest certain fundamental requirements that produce pumps of good performance, but there is no scientific way of assessing the influence of such variables as blade incidence, blade number or shape of blade or passageway. A theory is presented for optimizing the geometric parameters to give the best cavitation performance or alternatively to assess the influences of working away from the design. From this, a theoretical method based on cascade data transformed into the radial plane is used for detail design for given cavitation inception conditions. Following on this, a new method has been developed for predicting cavitation performance breakdown, based on linearized potential flow theory. Comparisons are made between these theoretical predictions and experimental data obtained both at NEL and those quoted in the literature. Agreement is on the whole very good.
Turbocharging the 3 Litre V6 Ford Essex Engine
Authors: Fuchs E. R. R. , Parker K. G. , Lovell B. T. Pritchard 
Published: October 2007

Power and torque improvements of 30 per cent and 26 per cent respectively have been produced by turbocharging. A compression ratio of 7·6:1 is employed and petrol of 97 octane number RM is adequate. An acceptable torque curve has been obtained by the use of a turbine outlet restrictor; the standard intake manifold is retained and the compressor delivers to the standard carburettor. A unique combination of vehicle performance and driveability has resulted and exhaust and intake noise is readily controlled. Only minor engine component changes are necessary and mechanical reliability presents no problems. Specific fuel consumption is no higher than that of the normally-aspirated version of the engine, and emision of oxides of nitrogen is low.
A New Concept of Truck Transmission Design
Authors: Morrison W. M. M. 
Published: October 2007

The object of this paper is to re-assess the existing principles used in the design of synchronized mechanical transmissions from the point of view of synchronizer duty. By a logical approach, when the main emphasis is given to synchronizer duty, a new transmission concept, known as the ‘M’ series, has been evolved, which brings with it some important advantages: saving of weight; faster synchronization, making for greater road safety; less space; lower manufacturing costs. The theoretical study compares the expected performance with that of a conventional five-speed synchronized transmission under identical conditions. Laboratory and road tests have established the validity of the theoretical appraisal.
New Family of High-Ratio Reduction Gears with Multiple Drive Paths
Authors: White G. 
Published: October 2007

A new family of high-efficiency, high-ratio reduction gears is described in which a counter-rotating epicyclic gear distributes power equally between two, three or four parallel drive paths. The mechanisms employ zero stiffness torque-balancing within and external to the epicyclic unit and work within a spectrum of operation bounded by designs having a fixed annulus or a fixed planet carrier. A theory is developed to investigate the principal design problems associated with reduction ratios, bearing speed, centrifugal loading, bearing life and epicyclic efficiency. A primary application is to high-output torque transmission systems such as those used in helicopters.
Third Paper: Lubricant Development for the Wankel-Type Rotary Engine
Authors: Beavis D. A. , Towle A. 
Published: October 2007

A review has been made of the factors which may influence the development of lubricants suitable for the Wankel-type engines. The lubricant requirements of the Audi-NSU Ro80 engine are discussed in comparison with the performance level of lubricants currently in use with conventional reciprocating piston engines. In Europe, high-speed pre-ignition has been one of the main causes for concern, but at the other end of the performance scale, cold wear of cast-iron apex seals under ‘stop and go’ driving conditions, created conflicting performance requirements for the lubricant under development. A compromise lubricant formulation has given complete freedom from pre-ignition and a marked decrease in the ‘cold wear’ rates, whilst maintaining the other desirable properties necessary for satisfactory Wankel-engine performance.
Second Paper: Predicting Nitric Oxide and Carbon Monoxide Concentrations in Spark-Ignition Engines
Authors: Daneshyar H. , Watfa M. 
Published: October 2007

Kinetic models, incorporating elementary chemical reactions, are used to predict the concentrations of NO (nitric oxide) and CO (carbon monoxide) in spark-ignition engines during the expansion process. The kinetic equations are*** incorporated in a cycle synthesis computer programme, which can be used to calculate the thermodynamic state and the concentration of a number of species in the burnt gas. The stability and accuracy of the programme is discussed and the validity of the results is confirmed by comparing the theoretical predictions with experimental results.