The Measurement of Errors in Gears for Turbine Reduction Drives

1947 ◽  
Vol 157 (1) ◽  
pp. 418-451 ◽  
Author(s):  
C. Timms
Keyword(s):  
Cutting Tools ◽  
National Physical Laboratory ◽  
The Past ◽  
Gear Cutting ◽  
Physical Laboratory ◽  
Gear Hobbing ◽  
Portable Instruments ◽  
The Relationship

The paper forms a review of the work carried out during the past six years at the National Physical Laboratory in connexion with the development of methods for measuring the errors of large gears for turbine reduction drives by means of a series of portable instruments. The relationship between these errors and the inaccuracies of gear-hobbing machines and gear-cutting hobs is discussed. Methods of determining these inaccuracies are described, together with information showing the improvements which have taken place in the accuracy of these machines and cutting tools resulting from the applications of the methods of testing.

The virial coefficients of the carbon dioxide-ethylene system I. Pure gases

1964 ◽  
Vol 277 (1371) ◽  
pp. 448-467 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Second Virial Coefficient ◽  
Virial Coefficients ◽  
Direct Determination ◽  
Expansion Method ◽  
National Physical Laboratory ◽  
Intermolecular Potential ◽  
Gaseous Mixtures ◽  
Physical Laboratory ◽  
The Relationship

This paper describes the first part of an investigation of the thermodynamic properties of gases and gaseous mixtures undertaken a few years ago at the National Physical Laboratory, with the main object of providing data on the relationship between the properties of mixtures and those of the pure constituents. The virial coefficients of carbon dioxide and ethylene have been determined by the series-expansion method over the range —10 to 200 °C, and the representation of the results by several forms of intermolecular potential has been investigated. In the case of ethylene it appears that the second virial coefficient may be represented accurately in terms of a Lennard-Jones 6:12 potential, the parameters of which are determined. In the corresponding representation for carbon dioxide there is a small but systematic discrepancy and evidence is adduced that this may be rectified by the introduction of a quadrupole interaction term on the lines of the theory developed by Pople. The value of the quadrupole moment suggested by this calculation proves to be in fairly close agreement with a recent direct determination. Work on the virial coefficients of mixtures of the two gases will be described in a further paper.

The Application of Computers to Life Assurance.

1961 ◽  
Vol 16 (03) ◽  
pp. 210-227
Author(s):  
T. B. Boss ◽  
K. H. Allen ◽  
A. C. Baker ◽  
D. W. Brackfield ◽  
R. B. Colbran ◽  
...  
Keyword(s):  
Study Groups ◽  
National Physical Laboratory ◽  
Computer Study ◽  
Ordinary Life ◽  
The Past ◽  
Life Assurance ◽  
Physical Laboratory

This report summarizes the conclusions reached and difficulties encountered by Group E in the discussions held over the past 4 years. It is thus an amplification and extention of the report made to a meeting of the various computer Study Groups held on 27 May 1957.The Group consists mainly of actuaries employed by ordinary life assurance offices (some composite and some purely life). The Chairman is a member of the Mathematics Division of the National Physical Laboratory, Teddington. The Group has been joined from time to time by representatives of computer manufacturers and other visitors.

12.—The National Physical Laboratory—Aspects of work on the primary standards of measurement

1972 ◽  
Vol 70 ◽  
pp. 125-141
Author(s):  
J. V. Dunworth ◽  
P. Dean
Keyword(s):  
National Physical Laboratory ◽  
New Techniques ◽  
The Past ◽  
Velocity Of Light ◽  
Physical Laboratory ◽  
The Future ◽  
Primary Standards ◽  
Infrared Frequencies ◽  
Very High

One of the traditional activities of the National Physical Laboratory is its work on the maintenance and improvement of the primary standards of measurement. Although one may possibly visualise such work, because of its long history and its association with calibration services, as of a largely routine character, this is certainly far from the case at the present time. The present is a period of considerable activity and change in fundamental metrology, with the classical material standards of measurement being superseded by atomic or quantum standards. The past decade has seen a change to atomic standards for the units of length and time, and there seems little doubt that the future will see an extension of atomic-based standards to other areas, notably that of the electrical quantities. Some of the changes which may come about as a consequence of adopting the most accurate and convenient quantum methods have interesting implications. For example, a possible outcome of the new techniques being developed for the accurate measurement of very high (infrared) frequencies is that the standards of length and time may become unified, with the velocity of light taking the role of an agreed defined constant rather than an experimentally determinable quantity.

scholarly journals VIII. Gaseous combustion at medium pressures. Part I. —Carbon monoxide air explosions in a closed vessel. Part II. —Methane-air explosions in a closed vessel

1926 ◽  
Vol 225 (626-635) ◽  
pp. 331-356 ◽  
Keyword(s):  
Carbon Monoxide ◽  
National Physical Laboratory ◽  
Closed Vessel ◽  
Engineering Research ◽  
The Past ◽  
Physical Laboratory ◽  
Wide Range ◽  
The Subject ◽  
Temperature And Pressure ◽  
Air Explosion

During the past five years a programme of research involving air-fuel explosions in a closed vessel has been in progress at the National Physical Laboratory for the Engineering Research Board of the Department of Scientific and Industrial Research. Among the experimental results obtained, those relating to Carbon Monoxide and Methane were considered likely to be of interest to the Society, and form the subject of the present communication. Of the two investigations described, the first gives experimental data on the respective influences of hydrogen-air and water vapour on a carbon monoxide-air explosion, and the second relates to explosions of methane and air over a comparatively wide range of initial temperature and pressure.

The Uses of the ACE Computor

1955 ◽  
Vol 59 (532) ◽  
pp. 279-281
Author(s):  
E. T. Goodwin
Keyword(s):  
National Physical Laboratory ◽  
Full Scale ◽  
The Past ◽  
Pilot Model ◽  
Physical Laboratory ◽  
Chief Interest ◽  
Automatic Computing

When I accepted the invitation to give a lecture on “The Uses of the ACE Computor” my first thought was to ask for the title to be corrected. The “ACE” as such has yet to be built and the machine that has been in use in the Mathematics Division of the National Physical Laboratory is a pilot model. However, to an audience whose chief interest is in aeronautics, the ambiguity of a title including the phrase “Pilot ACE” probably outweighs the advantage of its accuracy.As its name implies, the Pilot Ace was built,at the N.P.L., with the intention of testing out the practicability of various ideas in the design of a full scale automatic computing engine, or ACE as it was called. The over-riding consideration was economy of equipment but, despite the rudimentary nature of the facilities provided on the machine, it was found to be a fast and powerful computor and has been fully and successfully employed for the past three years on a 13 hour basis.

scholarly journals Address of the President, Sir Ernest Rutherford, O. M., at the anniversary meeting, December 1, 1930

1931 ◽  
Vol 107 (752) ◽  
pp. 348-368
Keyword(s):  
Medical Research Council ◽  
Great Part ◽  
National Physical Laboratory ◽  
Wide Field ◽  
Indirect Benefit ◽  
Ernest Rutherford ◽  
The Past ◽  
Physical Laboratory ◽  
Scientific Objects ◽  
Foreign Member

At this, our Annual Meeting, we are naturally conscious of the severe losses in our ranks in the course of the year. We have to deplore the removal by death of some of the best known and most valued Fellows, including Lord Balfour and Sir William McCormick, elected under Statute 12, Professor Le Bel, Foreign Member, and twelve Fellows of the Society. The death of the Earl of Balfour at the age of 82 removed from our midst a public figure of the first magnitude. Although Balfour's activities covered a wide field, and although a great part of his career he carried heavy responsibilities in guiding the affairs of the Nation, science was always with him a topic of primary interest. If he cannot be said to have made original contributions to scientific knowledge himself, there can be no doubt that his championship of the cause of science was of the greatest indirect benefit. As First Lord of the Treasury in 1900, he did much to help forward the scheme for the National Physical Laboratory, in which his brother-in-Law, Lord Rayleigh was interesting himself. He was constantly called upon to preside, or to speak, at meetings for the furtherance of scientific objects, or the commemoration of the great scientific careers of the past, and seldom failed to add distinction to such occasions. He may indeed be regarded as a chief interpreter of science to the English public during his generation. He was President of the British Association at Cambridge in 1904. He was elected to the Royal Society under Statute 12, as early as 1888, at the age of 40 years. He served on the Council in 1907-08 and again in 1912-14. But, perhaps, his chief work for science was the Minister responsible for the Department of Scientific and Industrial Research, and for the Medical Research Council. Of the latter body he acted as chairman until the onset of his illness. He watched the scientific interests under these departments with close personal attention, and did much to establish them on a permanent basis. Finally, to him was due the Committee of Civil Research, complementary to his order creation of the Committee of Imperial Defence. He was Chancellor of the Universities of Cambridge and Edinburgh, and President of the British Academy. His is a place which will not easily be filled.

Douglas Rayner Hartree, 1897-1958

1958 ◽  
Vol 4 ◽  
pp. 102-116 ◽  
Keyword(s):  
Numerical Computation ◽  
Public Service ◽  
Women's Organizations ◽  
National Physical Laboratory ◽  
Teaching Staff ◽  
National Council ◽  
Numerical Work ◽  
Physical Laboratory ◽  
The Relationship ◽  
Women’S Organizations

Douglas Rayner Hartree was born in Cambridge on 27 March 1897, and he died also in Cambridge on 12 February 1958. His genealogy furnishes an admirable illustration of the principle of heredity in ability, for he could claim to inherit many of his gifts and his scientific tastes from one or other of his parents. His father, who was a grandson of the famous Samuel Smiles, was for many years on the teaching staff of the Engineering Laboratory at Cambridge. He had retired from these duties in 1913, but on the advent of war in 1914 he took up work in the team led by Professor A. V. Hill which was studying anti-aircraft gunnery and cognate matters. This brought his son Douglas into the same team, and started him on the lines of doing numerical computation. After the war William Hartree co-operated with A. V. Hill in physiological experiments for a time, and then joined his son in numerical work. This he continued almost till his death in 1943, but the relationship was an exceptional one, because the son was the leader and the father ranked as the junior in this work. His mother, originally Eva Rayner, was daughter of a prominent physician in Stockport, and sister of E. H. Rayner who for many years was Superintendent of the Electricity Division of the National Physical Laboratory. She herself was active in public service and in various women’s organizations. She was at one time Mayor of Cambridge and she also served for a time as President of the National Council of Women.

scholarly journals Iron of high purity

1935 ◽  
Vol 153 (878) ◽  
pp. 172-200 ◽  
Keyword(s):  
High Purity ◽  
National Physical Laboratory ◽  
The Past ◽  
Oxygen System ◽  
Physical Laboratory ◽  
Metallurgy Department ◽  
Purity Iron ◽  
High Purity Iron ◽  
Commercial Iron ◽  
Made In

During the past eleven years (1925-35) several equilibrium diagrams involving iron as one of the components have been investigated at the National Physical Laboratory. The provision of the numerous alloys required for these researches has necessitated the production of quantities of high purity iron. Tritton and Hanson, when they began work on the iron-oxygen system at the National physical Laboratory, considered that the best commercial iron then obtainable was unsuitable for their work, and in the period 1922-24 prepared iron electronically according to the method of Cain, Schram, and Cleaves. At first the present authors produced iron in a somewhat similar manner, but when improvements in analytical methods revealed impurities in samples originally considered satisfactory, alterations were made in the method of preparation. Comprehensive analyses indicate that the latent batch of iron prepared the authors is very low in impurities, yet the physical properties of this material suggest that some disturbing factor may still be present. The problem is apparently complex and a rapid solution appears unlikely In these circumstances it was thought that the present publication of data concerning several batches of iron prepared at the National Physical Laboratory would serve a useful purpose. In addition to information obtained by the authors, particulars of a batch of iron prepared by Mr. W. E. Prytherch, M. Sc., also of the Metallurgy Department, N. P. L., are included, together with occasional results obtained by older members of tde staff. The results of Tritton and Hanson ( loc. cit .) are omitted, how-ever, as these have already been published.

scholarly journals On the conditions at the boundary of a fluid in turbulent motion

1920 ◽  
Vol 97 (687) ◽  
pp. 413-434 ◽  
Keyword(s):  
Fluid Motion ◽  
Frictional Resistance ◽  
National Physical Laboratory ◽  
Mean Velocity ◽  
Physical Laboratory ◽  
Frictional Forces ◽  
Set Up ◽  
Coefficient Of Viscosity ◽  
Bounding Surfaces ◽  
The Relationship

The experiments here described form part of a general research into the phenomena of skin friction of solid surfaces due to the flow over them of fluids whose motion, not in the immediate vicinity of the surface, is eddying or turbulent. Considerable information has been obtained in recent years as to the magnitude of the frictional forces brought into existence in this condition of flow, and the manner of variation of these forces with the relative mean speed of surface and fluid, the roughness of the surface, and the physical characteristics of the fluid is fairly well known. Practically nothing, however, is known about the mechanism by which the resistance to flow is transmitted to the bounding surfaces. For speeds below the critical when the general motion of the fluid throughout is streamline in character, it is generally accepted that the layer of fluid in contact with the boundary is at rest relative to it, as any slipping of finite amount would be detected in a variation from the Poiseuille law of the relationship between the diameter of a pipe and the time of efflux of a given volume of fluid. At speeds above the critical, observations near the walls have shown that the mean velocity falls rapidly as the solid bounding surface is approached, and it has been suggested that at the walls there may exist a thin layer in which the flow is laminar in character, in which case, if there is no slipping, the frictional resistance would be determined from the slope of the velocity curve in the surface layer and the coefficient of viscosity of the fluid. During the last few years several attempts have been made at the National Physical Laboratory to obtain evidence as to the truth of this assumption. The method adopted has been to set up a condition of turbulent fluid motion over a surface of which the frictional resistance to the flow could be accurately determined, and to measure by means of a very fine Pitot tube the velocity of the fluid at a point as near the wall as possible.

An Application of Carpet and Lattice Plotting

1953 ◽  
Vol 57 (506) ◽  
pp. 107-110
Author(s):  
R. Tatham
Keyword(s):  
Graphical Representation ◽  
Engine Performance ◽  
National Physical Laboratory ◽  
Performance Data ◽  
Graphical Form ◽  
Continuous Approximation ◽  
Direct Solution ◽  
Graphical Data ◽  
Physical Laboratory ◽  
The Relationship

The carpet and lattice methods of plotting the relationship between three and four variables respectively, developed by R. F. Sargent, of the National Physical Laboratory, have been described previously by A. H. Yates, who gave examples related to the presentation of aerodynamic and engine performance data. Outside these fields there appears to be still some lack of appreciation of the usefulness of this form of graphical representation, although it is capable of wide application. The writer has found both carpet and lattice plotting of great value in connection with the preparation of structures data sheets, and is convinced that interpolation is generally rendered easier and more accurate if graphical data are presented in this way. In one particular instance it was found possible to develop a nomogram in the form of an “ extended lattice ” plot, which gave in graphical form a direct solution to a set of equations which could be solved otherwise only by continuous approximation.

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