Affiliation:
1. de Beers Professor of Mechanical Engineering, University of the Wirwatersrand, Johannesburg, South Africa.
2. Lecturer, Department of Mechanical Engineering, University of the Witwatersrand, Johannesburg, South Africa.
Abstract
The paper describes the development of a method of investigation, both analytical and graphical, into problems relating to internal combustion motor design and performance. The authors have provided a chart, together with auxiliary graphs, by means of which theoretical indicator diagrams may be constructed for any internal combustion engine cycle under conditions of variable specific heat. It may also be used for studying any indicator diagram obtained under test conditions. The main feature of the chart is the provision of means to enable it to be used for any hypothetical or initial conditions encountered in practice. It has been so generalized as to enable it to be used, not only for the examination and construction of indicator diagrams involving expansion down to atmospheric pressure or to the initial compression volume, but to any degree. The auxiliary graphs provide a means whereby the thermal efficiency, mean effective pressure, and other essential quantities may more easily and readily be calculated than has previously been possible. To illustrate the method of using the charts and graphs, examples have been worked out for the dual combustion cycle, the Diesel cycle and the constant volume cycle.