Author
Vincent T. Morgan
Bio: Vincent T. Morgan is an academic researcher from Commonwealth Scientific and Industrial Research Organisation. The author has contributed to research in topics: Electrical conductor & Rayleigh number. The author has an hindex of 5, co-authored 10 publications receiving 926 citations.
Papers
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TL;DR: In this paper, it was shown that the error due to heat conduction to the supports is particularly important with natural convection, especially where the heat loss and the temperature rise of the cylinder are calculated from the voltage drop across it.
Abstract: Publisher Summary Accurate knowledge of the overall convective heat transfer from circular cylinders is of importance in a number of fields, such as boiler design, hotwire anemometry, and the rating of electrical conductors. The wide dispersion in the published experimental data for the heat transfer from smooth circular cylinders by natural and forced convection is attributed to various factors associated with the experiments. The error due to heat conduction to the supports is particularly important with natural convection, especially where the heat loss and the temperature rise of the cylinder are calculated from the voltage drop across it. A common cause of error is the use of too small a space ratio, so that the temperature and velocity fields are distorted. To reduce this error to less than l%, the space ratio D c /D for natural convection or D T /D for forced convection should exceed 100. The error caused by blockage with wind tunnel measurements can be calculated depending on the type of tunnel. One of the greatest sources of error with forced convection is the failure to allow for the effect of stream turbulence.
761 citations
TL;DR: In this paper, a thermal model to calculate the relationship between the current and the conductor temperature is proposed, and the parameters in the model are examined in detail, where the current rating of short transmission and distribution lines is often determined by the maximum permissible temperature of the conductors.
76 citations
TL;DR: In this paper, the authors examined the effect on the loss of strength of the reduction in cross-sectional area during drawing, the operating temperature, and the time duration of annealing.
Abstract: Although the literature contains many results of tests on the loss of tensile strength of wires held at various temperatures for various time durations, the data are very disperse, and it is difficult to apply them to determine the loss of strength of a particular conductor as a result of long-term annealing in service. This paper examines the effect on the loss of strength of the reduction in cross-sectional area during drawing, the operating temperature, and the time duration of annealing. The effect of the heat capacity of wires and conductors on the loss of strength following a short-circuit or a lightning impulse current is shown. The need for more work to determine the effects of tension and stranding on the loss is stressed.
51 citations
TL;DR: In this paper, the characteristics of the wind at 10 m height were studied over a period of 32 months and the sampling interval was 20 ms and the averaging time was 10 min.
51 citations
TL;DR: The thermal rating of an overhead-line conductor is the current required to produce a certain maximum permissible temperature under specified atmospheric and other conditions as discussed by the authors, and the sensitivity of the thermal rating to a variation of each parameter over a practical range is examined.
20 citations
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01 Jan 1997
TL;DR: In this article, the analogy between heat and mass transfer is covered and applied in the analysis of heat transfer by conduction, convection and radiation, and the analysis is performed by using the handbook of numerical heat transfer.
Abstract: Handbook of Numerical Heat Transfer Free Full Download Links from Multiple Mirrors added by DL4W on 2015-04-10 02:13:35. Handbook of heat transfer / editors, W.M. Rohsenow, J.P. Hartnett. Y.I. Cho. m 3rd ed. p. cm. Includes bibliographical references and index. ISBN 0-07053555-8. Students investigate heat transfer by conduction, convection and radiation. The analogy between heat and mass transfer is covered and applied in the analysis.
1,644 citations
TL;DR: In this article, a single comprehensive equation is developed for the rate of heat and mass transfer from a circular cylinder in crossflow, covering a complete range of Pr (or Sc) and the entire range of Re for which data are available.
Abstract: A single comprehensive equation is developed for the rate of heat and mass transfer from a circular cylinder in crossflow, covering a complete range of Pr (or Sc) and the entire range of Re for which data are available. This expression is a lower bound (except possibly for RePr < 0.2); free-stream turbulence, end effects, channel blockage, free convection, etc., may increase the rate. In the complete absence of free convection, the theoretical expression of Nakai and Okazaki may be more accurate for RePr < 0.2. The correlating equation is based on theoretical results for the effect of Pr in the laminar boundary layer, and on both theoretical and experimental results for the effect of Re. The process of correlation reveals the need for theoretical results for the effect of Pr in the region of the wake. Additional experimental data for the effect of Pr at small Pe and for the effect of Re during the transition in the point of separation are also needed.
849 citations
TL;DR: In this article, the authors investigated heat transfer and pressure drop phenomena over a bank of micro pin fin and found that very low thermal resistances are achievable using a pin fin heat sink.
419 citations
TL;DR: In this paper, the statistical data of eleven years' wind speed measurements of the capital of Iran, Tehran, are used to find out the wind energy potential, and other wind characteristics with the help of two methods of meteorological and Weibull are assessed to evaluate of which at a height of 10 meters above ground level and in open area.
358 citations
TL;DR: In this article, the authors present a review of the state-of-the-art LED packaging and application technologies, focusing on heat generation in chips, heat flow in packages and application products, fluid flow in phosphor coating process, etc.
350 citations