Use this URL to cite or link to this record in EThOS: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.777129
Title: Improvements in the performance analyses of internal combustion engine cycles
Author: Bruges, Edward A.
Awarding Body: University of Glasgow
Current Institution: University of Glasgow
Date of Award: 1957
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Abstract:
The purpose of this thesis is to collate the analytical and experimental work carried out by the writer in the field of Applied Thermodynamics concerning the performance analyses of internal combustion engine cycles, actual and theoretical. In view of the diversity of the subject matter the material is presented in eleven separate, though not unrelated, sections, so that each section is to a certain extent complete in itself. The work divides itself into three main parts, the determination and tabulation of properties of gases, the construction of energy charts and the application of a Second Law Analysis to theoretical and actual cycles. The publication of "Tables of Properties of Gases" (1)* by Dr, E, W, Geyer and the writer was the result of a combined effort to produce tabulated values of properties of gases, having in mind the requirements of calculations connected with dissociation at high temperatures and pressures in engine cylinders. All the calculations appearing in this thesis are based on the properties appearing in the above publication. It is intended to avoid repetition of the principles set down in the book but to furnish some additional background information. Accordingly the writer Numbers refer to bibliography on page 130 has prepared a section on specific heats which is in the main historical and is designed to lead up to a short section on tabulated values of thermal properties. The latter section includes discussion of "Gas Tables" (2) of which a review by the writer was published in Engineering (3) In "Tables of Properties of Gases" the establishment of the equilibrium constant was by means of the van't Hoff equilibrium box. A more elegant method is obtained using (4) Gibba function and a treatment taken from Roberts' and, modified, is presented here. The natural development from tabulated properties is to the construction of energy charts, especially for dissociated gas mixtures. Apart from the work of Hershey, Eberhardt and Hottel (5) this was not a field where there was much previous work. The writer has had to be content with providing the basic theory and a simple illustration of the use of such a chart(6). The computation of charts similar to those of the above workers would constitute too heavy a task for a single worker. However, the theory as reproduced here is an improved version of the published work and the writer believes that this contribution to the theory is to a certain extent original. The particular point is emphasised in both sections5 and 7. A new approach to the assessment of plant performance is made possible by means of the Second Law Analysis, a method of analysis suggested first by Keenan (7) and one which does not seem to have been developed. It was with a view to renewing interest in this method of analysis that the writer published two articles, whore the analysis was shown for a number of different plants. The object of a Second Law Analysis is to give a numerical value to the thermodynamic loss or "irreversibility" in any process. This is done by means of the concept of available energy or availability, to use the term Keenan coined. Although this type of analysis enables one to put a figure on a thermodynamic loss it does not point the way to removing the loss, and for a quick and general assessment of performance the conventional energy account is naturally to be preferred. In certain cases where a comparison between one plant arrangement and another is being made, particularly in the more complicated arrangements, the Second Law Analysis is of value. The method has the advantage of a thermodynamic basis, an advantage which shows itself very clearly in the application to combustion chamber performance. It may be that with the complexities of future plant a more refined method of analysis such as this will come into general use. In this thesis the application of the analysis is to internal combustion engine performance. Except for an application given by Keenan(10) and this is to an ideal cycle, the writer knows of no other work where the analysis is given for an internal combustion engine, either in a theoretical or actual case. The concluding sections of this thesis are devoted to the application of the Second Law Analysis to Ideal and actual cycles.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.777129  DOI: Not available
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