bluuebunny/crossref_metadata_2025_split huggingface dataset:
Paper 4: High-Output Medium-Speed Diesel Engine Air and Exhaust System Flow Losses
Authors: Wallace W. B. 
Published: June 2010

This paper gives the results of air-flow tests through two-stroke cycle and four-stroke cycle diesel engine cylinder heads and ports on steady-flow low-pressure air flow rigs. An analysis is made of the pressure drop through a diesel engine cylinder head inlet port system which shows the effect of the various parts of the system on flow loss. This also includes the effects of valve lift, valve seat angle, and valve shape on isentropic area. A comparison is made between tandem and Siamese porting on a four-stroke cycle engine cylinder head. The results of tests on uniflow scavenged two-stroke cycle inlet ports and exhaust valves are also included.
Paper 8: Thermal Comfort
Authors: Chrenko F. A. 
Published: June 2010

The subjects of heating and ventilating are very wide and their practical applications necessitate much detailed technical information. This is given very satisfactorily in the usual textbooks written for engineers. However, such books are apt to deal somewhat hastily with the theories upon which good practice should always be based. This applies especially to the subject of thermal comfort. It is evident that large diversities of opinion are apparent when people are questioned concerning their feelings of warmth over quite a wide range of temperature. This has led some to state that it is better not to rely upon personal feelings of comfort in environmental investigations. The following brief introduction to thermal comfort endeavours to show not only that this is a mistaken notion but that the subjective factors of thermal comfort have been successfully assessed and correlated with the physical factors of the environment.
Paper 3: Application of Factory-Made Air-Conditioning Units
Authors: Taylor F. M. H. 
Published: June 2010

The paper states why air conditioning is necessary particularly in office blocks in cities, where noise, dust and heat from office machinery together with solar heat gain through large glass areas are experienced. The relatively small addition to building costs in incorporating air conditioning is shown. The distinction between air handling, ventilation and air conditioning is defined and the constituent parts of a complete air-conditioning unit are enumerated. The requirements in terms of fresh air needs, temperature and relative humidity for the normal applications of air-conditioning units are tabulated. A comparison of the main categories of air-conditioning equipment is made, dealing with high and low velocity as well as special laboratory type units. A typical performance specification is also given together with data sheets for collecting the necessary design data and cost comparisons. The paper concludes with a discussion on system design incorporating factory-made equipment and literature references.
Report 5: An Optical Method of Measuring Film Thickness
Authors: Higginson G. R. , Reed S. 
Published: June 2010

This report describes a method which is being developed specifically to measure the film thickness in a journal bearing carrying a steady load. In such a bearing the lubricant film is essentially parallel and its area very large. The requirement therefore is for a method which will measure a local value of the distance between two curved but parallel surfaces about 10 μ apart. The optical method described below can be used either in transmission with two transparent bodies or in reflection with one transparent and one opaque. In the intended applications the reflection technique will be used, with a semi-reflecting layer on the surface of the transparent body.
Report 13: Pressure Developed in the Lubricant Film between Two Contacting Surfaces in Relative Motion
Authors: Fergusson B. , Ross D. , Ismail M. A. , Gohar R. 
Published: June 2010

An apparatus has been developed for the measurement of the pressure distribution in the lubricant between a roller and a flat plate in relative motion. A hole of diameter 0002 in is drilled in a flat plate which is mounted on a co-ordinate table. A traverse of the pressure zone in two directions is effected by moving the co-ordinate table in discrete steps, so that the lubricant pressure at each location is transmitted through the small hole. Connecting to the small hole is a pressure transducer which feeds a signal, proportional to the pressure, to an ultra-violet recorder. Conversion of the recorder print-out to pressure is accomplished by calibration of the transducer and the recorder against known pressures
Report 22: Experimental Techniques for the Assessment of Temperatures Attained by Sliding Surfaces
Authors: Powell D. G. , Earles S. W. E. 
Published: June 2010

Research has indicated that surface temperature is of prime importance in determining the behaviour of materials suitable for use in sliding bearings. Consequently, some assessment of the surface temperature developed is desirable in many investigations of the tribological properties of a combination of materials and environment. This report outlines the experimental techniques available for measuring surface temperature, several of which, though developed basically as research tools, are suitable for routine testing. The capabilities and limitations of each method are discussed and, in deciding the most convenient method to use, in practice must be jointly considered with the type of temperature variation which is to be expected.
Paper 4: Terminal Laminar Convection in a Uniformly Heated Rectangular Duct
Authors: Morris W. D. 
Published: June 2010

For the laminar flow of a fluid with constant properties in a uniformly heated rectangular duct with no viscous dissipation and internal heat release, an exact solution for the fluid temperature field is presented in the form of rapidly convergent infinite series. Expressions are subsequently derived for the variation of limiting Nusselt number, based on unweighted and weighted mean temperature differences, with duct aspect ratio. It is shown that previously published approximate solutions for the weighted Nusselt number—determined using numerical techniques—are in agreement with the more versatile exact solution to better than 1 per cent.
Paper 6: A Rotating Pressure Transmission System for Turbo-Machinery Experiments
Authors: Hodskinson M. G. 
Published: June 2010

Experimental investigation of air flow in rotating blade rows is widely regarded as desirable, but is rendered difficult in practice because of high rotational speeds and the large number of pressure tappings required. The design and operation of a system using the Scanivalve and able to transmit pressures from a rotor running at 8000 rev/min is described in this paper. Some experience in the use of the system with blade surface measurements on a small (8-in diameter) centrifugal impeller is discussed. Attention is paid to sources of error in pressure readings, including the rotating head correction to convert the transmitted pressure reading into actual pressure at the point of measurement. Theoretical relative velocities in the impeller have also been obtained with Algol computer programmes for isentropic flow in the axi-symmetric and blade-to-blade directions. A comparison is made between experimental and theoretical relative velocities in the impeller in which the flow is essentially incompressible at the test speed. It is concluded that flow separation occurs early in this particular impeller channel. On the evidence of the results obtained so far, some further uses and developments of the pressure transmission system are discussed.
Paper 17: Inception of Nucleate Boiling of Water at Pressures above Atmospheric: Characteristics of a Horizontal Surface Bearing a Normal Distribution of Cavities
Authors: Grant I. D. R. , Patten T. D. , Carrie G. M. H. 
Published: June 2010

It is known that the onset of nucleate boiling at a solid surface is related to the dimensions of cavities on the surface. In this paper it is proposed that a commercial surface be characterized by a normal distribution of cavity sizes, and on this basis a theory is developed for the prediction of heat transfer characteristics in the weak nucleate boiling regime. The theory is developed simultaneously with the presentation of the results of experiments carried out on pool boiling of water from a heating surface bearing cavities of equivalent radii from 50 to 550 μin. Discrepancies between experiment and theory are discussed. Experimental data on the influence of pressure (range, atmospheric to 750 lb/in2 (abs.)) and subcooling (range 0–12 degF) on the overall heat transfer rates are also presented.
Paper 20: Application of Non-Steady Flow in a Rotating Duct to Pulsating Flow in a Centrifugal Compressor
Authors: Benson R. S. , Whitfield A. 
Published: June 2010

This paper deals with a theoretical approach to study the non-steady flow and wave action in a centrifugal impeller and vaneless diffuser, and also to predict the non-steady flow performance of a centrifugal compressor. This was carried out by replacing the compressor unit by a model which consisted of a simplified rotating duct, a vaneless diffuser, and a cone-shaped pipe which replaced the scroll. A theoretical technique using the method of characteristics and the development of the non-steady flow equations to a rotating duct and radial diffuser is given. The development of the theory and the difficulties encountered are described. In particular, the techniques developed for starting a computer calculation are described. In order to maintain homentropic flow in the impeller and diffuser all losses were assumed to occur at the impeller inlet. A pressure loss boundary condition was developed to enable the steady pressure ratio-mass flow characteristics to be computed. When these values agreed with the experimentally determined characteristics, the boundary condition at the rotor inlet was such that the pressure loss terms allowed for the impeller and diffuser losses. The theoretical results obtained are compared with corresponding experimental results, and the possibility of using this theoretical technique as a design tool is discussed.
Paper 24: Heat Transfer in Rotor Cooling Ducts
Authors: Le Feuvre R. F. 
Published: June 2010

This paper is concerned with heat transfer to air passing through the axial cooling ducts of rotors. The measurements have yielded data for a range of axial to rotational velocities and of duct spacing, pitch-circle diameter, and length-to-diameter ratio. The results, in terms of the ratio of rotating to stationary heat transfer coefficients, show the important parameters which govern the increase in heat transfer due to rotation. Under certain conditions, an increase in heat transfer of 100 per cent is achieved.
Paper 27: Heat Transfer to Steam-Water Mixtures Flowing in Uniformly Heated Tubes in which the Critical Heat Flux has been Exceeded
Authors: Bennett A. W. , Hewitt G. F. , Kearsey H. A. , Keeys R. K. F. 
Published: June 2010

Experiments are described on evaporative heat transfer to boiling water in upflow in a vertical electrically heated 0·497-in inside diameter tube at 1000 lbf/in2 (abs.). The main objects were to measure the surface temperature profiles in the region beyond the dry-out point in the channel where liquid ceased to flow on the channel wall, and to investigate the behaviour of the dry-out ‘interface’ between the ‘wetted wall’ and the ‘dry wall’ regions. The test section was made from ‘Nimonic’ as this can withstand the highest temperatures in the ‘dry wall’ region and also has a low temperature coefficient of electrical resistivity, thus allowing a uniform heat flux to be maintained with wide axial temperature variation. The temperature in the ‘dry wall’ region first increased rapidly with distance from the dry-out point, after which it either increased at a slower rate or, at high mass velocities, even decreased. The dry-out ‘interface’ moved reversibly down and up the channel as the heat flux was increased and decreased. Local surface temperatures showed no hysteresis with cycling of heat flux, in contrast with the pool boiling situation. A method of predicting the wall temperature profile in the ‘dry wall’ region has been developed. In this method, the heat-transfer process is considered as being in two steps: wall to superheated steam continuum, and steam continuum to water droplets. The first step was calculated from standard single-phase steam heat-transfer correlations, and the second step was calculated on the basis of simultaneous heat transfer to, and steam diffusion from, the droplets. It was important to take account of the slip between the droplets and the steam. Satisfactory agreement was obtained between measured and predicted wall temperature profiles.
Paper 28: Turbulent Heat Transfer to Air in the Vicinity of the Entry of an Internally Heated Annulus
Authors: Roberts A. , Barrow H. 
Published: June 2010

A new theoretical analysis has been made of turbulent heat transfer in the region of simultaneously developing hydrodynamic and thermal boundary layers in annular flow. A boundary layer-potential stream model has been used to describe the flow, heat transfer being predicted through the use of a modified Reynolds analogy. Skin friction data for the inner heated wall have been obtained from correlations pertaining to boundary layers on immersed bodies. Experiments have been made with air in the entry region of internally heated annuli with radius ratios 2·1 and 4·0. Satisfactory agreement between theory and experiment has been achieved.
Paper 29: Heat Transfer during Two-Component Mist Flow across a Heated Cylinder
Authors: Finlay I. C. , McMillan T. 
Published: June 2010

The results of a study of heat transfer and hydrodynamic phenomena during flow of an air-water mist across a heated, horizontal cylinder are reported. Local and average heat-transfer coefficients have been obtained, under conditions of constant heat flux, on the outer surface of a 19-mm outside diameter cylinder. Air flow rates corresponding to approach velocities of 20–75 m/s have been explored with mixture qualities in the range 0–9 per cent by weight of liquid phase. Heat-transfer coefficients were found to be strongly dependent on mixture quality, and increases in the average value of the surface heat-transfer coefficient of twenty times the corresponding dry gas values were recorded with mixture qualities approaching 9 per cent by weight of liquid. Under all conditions explored, a liquid layer was observed to form over the front half of the tube, between forward stagnation and separation. An intense bouncing or splashing action of droplets impinging on this layer was observed and measured. Average values of surface heat-transfer coefficient were found to be correlated in terms of the quality and Reynolds number of the mixture and of Nusselt numbers based on average and stagnation point heat-transfer coefficients.
Paper 9: The Measurement of Turbulent Velocity Fluctuations and Turbulent Temperature Fluctuations in the Supercritical Region by a Hot Wire Anemometer and a ‘Cold’ Wire Resistance Thermometer
Authors: Bourke P. J. , Pulling D. J. , Gill L. E. , Denton W. H. 
Published: June 2010

It is necessary to develop experimental methods for measuring the local turbulent velocity and turbulent temperature fluctuations in the supercritical region in order to investigate the unusual heat transfer phenomena that occur in heating turbulent flows of fluids in this region. The performance of the constant temperature hot wire anemometer has been investigated in isothermal turbulent flow of carbon dioxide in a pipe at supercritical pressures from 1075 to 1200 lb/in2 ( Pc = 1071 lb/in2) and at temperatures from 24·5 to 40°C ( Tc = 31°C), including the critical range of rapid variation in physical properties in which the fluid changes from liquid to gas. The wire temperature was varied and linear mean velocity calibrations were obtained which were found to be markedly sensitive to the pressure, the fluid bulk temperature, and the wire temperature. Measurements of turbulent velocity fluctuations agreed with the expected values for this isothermal case. The heat transfer from the wire showed no unusual characteristics and was correlated for variation in pressure, fluid bulk temperature, and wire temperature by using mean values of the physical properties over the wire to bulk temperature range. Because of the sensitivity of the wire calibrations to temperature, measurement of the local fluid temperature is required to allow velocities to be measured in the presence of temperature gradients in the supercritical region. A probe has therefore been developed with a thin cold wire resistance thermometer, mounted close to a pair of crossed hot wires and with a sufficiently fast thermal response for the measurement of temperature fluctuations as well as mean temperature. Experiments are described with this probe in the presence of temperature gradients in turbulent flow, but so far only in air. Simultaneous measurements were made of both the radial velocity fluctuations and temperature fluctuations in a volume of air that was small compared with the scale of turbulence. The time-correlation of these two quantities was found to be strong near the wall of the tube and to fall to zero towards the centre. Further, the local radial turbulen theat flux calculated from the mean product of these two quantities agreed quantitatively with the known heat flux for various radial positions in the tube. The remaining problem is to investigate the effects that temperature fluctuations in the supercritical region have upon the measurement of velocity fluctuations and on the local values of the density and specific heat.
Paper 5: Experience in Corrosion Control
Authors: Heslop S. 
Published: June 2010

The term ‘corrosion’ is used to cover the many and varied effects of an environment upon a solid object. The environment may include solid, liquid and gaseous phases, vapours, electromagnetic radiation (visible light plus infra-red and ultra-violet rays), mechanical vibrations and energy, heat and electrical effects, or a combination of two or more characteristics which may promote or restrict its action upon the object subject to such influence. An appreciation of the mechanisms which produce corrosive effects enables preventive action to be taken in the design stage. This in particular involves the correct selection of materials and finishes, but incorporates also a knowledge of the particular environment to which the part will be exposed. When there is a clear understanding of the possible sources of corrosion, then means of protection may be specified or developed. The correlation of laboratory testing procedures to actual outdoor exposure is a difficult and time-consuming exercise which involves the selection of an open-air or part-covered site which has such constancy of conditions that it may be used all the year round without consideration of season, providing that the exposure time is not less than approximately three months. In temperate zones the times of sunrise and sunset deviate more than four hours throughout the year and similarly the temperature, the water vapour content of the atmosphere, and the cloud cover may vary enormously. This leads to the conclusion that the location of a suitable test site must be on or near the equator, it must have a maritime exposure, and also have characteristic features of uniform temperature, consistent sunshine, high humidity, and copious rainfall.
Paper 45: Tribological Implications of Surfaces
Authors: Barwell F. T. 
Published: June 2010

A major part of an engineer's concern with surfaces relates to their interaction within machine elements and to their degradation as a consequence of wear. Relevant work in this field is reviewed with particular reference to the Conference on Lubrication and Wear held at the Institution in September 1967. Two important quantitative measures which relate surface finish with functional factors have been described. One, the Plasticity Index, relates the topographic with the material characteristics of a surface and is defined as follows: where H = hardness, σ = standard deviation of asperity height distribution and β = asperity radius. γ1 and γ2 and E1 and E2 are the Poisson's ratios and moduli of elasticity of the materials of the two surfaces respectively. The other relates particularly to conditions of elastohydrodynamic lubrication and takes the form where h = uniform macroscopic lubricant film thickness and σ1 and σ2 are the r.m.s. surface roughnesses of the two surfaces in contact respectively.
Paper 17: Microtopography of Surfaces
Authors: Williamson J. B. P. 
Published: June 2010

This paper describes an approach to the study of surfaces based on the digital analysis of data obtained from profilometric examinations. This technique is used to determine several new surface texture parameters, including the surface density, height distribution, and mean radius of curvature of the asperities. Recent theories have shown that these are the parameters which control the nature of surface contact. The implications which these ideas have for the science of metrology are discussed. The study also shows that many surfaces have height distributions which are Gaussian, and in particular that the heights of the upper half of most surfaces closely follow a Gaussian distribution. By combining data obtained from many closely spaced parallel profiles it has been possible to reconstruct detailed maps of the surface texture. Two examples are discussed: bead-blasted aluminium, and a glass surface lightly blasted with alumina. One of the advantages of microcartography is that it permits the geometry of the contact between rough surfaces to be studied in detail. A map is given showing the manner in which the contact area between two bead-blasted aluminium surfaces splits into sub-areas, and how these sub-areas are distributed with respect to the surface features of the contacting solids.
Paper 2: Surface Topography Effects in the Estimation of Thermal and Electrical Contact Resistance
Authors: Yip F. C. , Venart J. E. S. 
Published: June 2010

A method of determining the constrictional thermal contact resistance is proposed and discussed. Consideration is given to modelling the simultaneous effects of asperity distribution and roughness, and surface waviness. The resulting general analysis can be applied to any known surface topography in contact with another. Application and comparison utilizing the method are made to the results of an electrical analogue study.
Paper 22: Metal Surfaces in Contact under Normal Forces: Some Dynamic Stiffness and Damping Characteristics
Authors: Andrew C. , Cockburn J. A. , Waring A. E. 
Published: June 2010

This paper describes an experimental investigation into the dynamic stiffness characteristics of flat joints subjected to an alternating force superimposed on a steady pre-load. The joints consist of the interfaces between mild-steel discs arranged in a column, in sets with surfaces either turned or lapped together. The influences of pre-load and of alternating force frequency were investigated for both dry and oiled joints, for different values of surface finish, apparent joint area and oil viscosity. The ranges of the conditions considered are compatible with those existing in typical machine tool structures. It was found that the dynamic stiffness of dry joints is independent of frequency and no energy dissipation is measurable. The stiffness is primarily a function of pre-load and surface finish, with apparent joint area becoming important only for very good surface finishes. If oil is introduced into the joint interface, a quadrature stiffness component arises and is accompanied by an increase in the ‘in-phase’ stiffness component. The magnitudes of the oil film stiffness components decrease sharply with an increase in the effective oil film thickness, which is governed primarily by the surface roughness. They increase with oil viscosity, the apparent joint area and the frequency of vibration, and represent a potentially valuable source of vibration damping in engineering structures.