Effective Combustion as Determined from the Indicator Diagram 340103
THE paper sets forth a simple and rapid method of obtaining from the indicator diagram data on how, when, and at what pressure combustion takes place in an internal-combustion engine.
An indicator diagram predicated upon time-pressure is analyzed by superimposing on the normal diagram a diagram taken without ignition of fuel. This is done either by shutting off the fuel, or by short-circuiting the ignition, as the case may require, and immediately recording a second diagram on the card. Polytropic curves are then constructed on the card and their intersections with the curves of the ordinary diagram indicate the several percentages of effective combustion.
Mr. Slonneger uses the term “effective combustion” to distinguish it from “complete chemical combustion” and from combustion losses due to conduction, radiation and leakage. A more technical analysis of Mr. Slonneger's method, according to thermodynamics and chemistry, is given in the Appendix.