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About this book

Upon an exponential growth of life on earth, supported by a century of oil­ based energy economy, following a century of its coal-based phase, the world we live in is facing a point of inflection! at the threshold of an expo­ nential decay. It is, in fact, the quest for counteracting its dreaded conse­ quences that are bound to follow, which half a century ago provided the stimulus for launching the space program. Coal and oil are made out of carbon and hydrogen atoms. Hydrocarbon molecules consisting of these atoms are the essential ingredients of life by providing energy in a remarkably compact from. This property is due to the fact that hydrocarbons, by themselves, are not highly energetic materi­ als. The energy is derived from them by chemical reaction with oxygen supplied by the surrounding air. This reaction provides heat and is referred to for that reason as exothermic. The mass of oxidizer it requires is, in fact, ~ 3. 5 (if it is provided by oxygen alone) or ~ 15 (if it is supplied by air) times larger than that of the hydrocarbon. For vehicular transport, where the fuel has to be carried on board, this feature is of particular significance.

Table of Contents

Frontmatter

Synthesis

Frontmatter

1. Overview

Abstract
The sole purpose of combustion in a reciprocating piston engine is to shift the expansion process away from the compression process in order to generate a working cycle. The only reason for the use of fuel is to generate pressure in order to accomplish this task. This is accomplished by an exothermic (one associated with acquisition of internal energy) chemical reaction, as a consequence of which a transformation (metamorphosis) takes place in engine cylinder between the reactants at initial state, i, attained at the end of the process of compression, and the products at final state, f, established at the start of the process of expansion, as depicted on the pressure-volume (indicator) diagram in Fig. 1.1.
Antoni K. Oppenheim

2. Perspective

Abstract
The literature on processes taking place in the cylinder of an internal combustion engine is very rich, indeed, as should be expected of a topic bearing so incisively upon the automobile and oil industries that occupy today a most prominent economic sector in the world. This is manifested, of course, by the textbooks on piston engines1, as well as by classical monographs on combustion2.
Antoni K. Oppenheim

3. Prospective

Abstract
We are living today in exciting times of spectacular advances in high-tech — a progress highlighted by the advent of micro-electronic control systems of nanosecond resolution. So far, the execution of the exothermic process of combustion (known, unfortunately, under a misleading name of “heat release”) has been considered (appropriately for this misnomer) to be beyond any control. As a consequence of this misconception, the automotive industry acquired the practice of a “hands-off” technology of combustion. Everything possible is done to refine the fuel, provide it with more-or-less useful additives, and igniting it, either by spark or by compression, but, once the fuel is ignited, the rest is considered to be in the hands of God. The question one may pose is what can be done to foster progress and what can be thereby achieved (Oppenheim 2002).
Antoni K. Oppenheim

Analysis

Frontmatter

4. Diagnosis

Abstract
As pointed out at the outset, the sole purpose of combustion in a piston engine is the generation of pressure in order to shift the expansion process away from compression and create a work-producing cycle. This transition is manifested by dynamic symptoms: the measured pressure profiler and the concomitant piston motion. Its action is referred to, therefore, as the dynamic stage of combustion. The generation of pressure is motivated by thermochemical transformation of reactants into products taking place in the course of a process referred to as the exothermic stage Changes in the composition and thermodynamic states of the reacting substances (metamorphosis) taking place within this stage are deduced from the measured time profile of pressure — the procedure of pressure diagnostics. Treated thus is an inverse problem: deduction of information on an action from its recorded outcome. Its solution yields, in effect, a measure of the effectiveness of the exothermic process of combustion in a piston engine, akin to the account of an auditor on the operation of a business enterprise from the records of its transactions — a well established methodology in acquiring guidance for its improvement.
Antoni K. Oppenheim

5. Procedure

Abstract
A step-by-step sequence of operations to be carried out to implement the technique of pressure diagnostics, presented in the previous chapter, is as follows.
Antoni K. Oppenheim

6. Prognosis

Abstract
Pressure diagnostics furnishes a fundamental procedure for design analysis of a combustion system for piston engines. It ushers in thereby a rational method of approach to the prediction of improvements in performance that can be attained by any contemplated modifications of the system prior to their design and testing. In view of the highly developed technology of modern internal combustion engine, such improvements can be derived only from the principles of the Second Law of Thermodynamics, rather than the First Law, in particular reduction in irreversible effects due to energy loss incurred by heat transfer to the walls.
Antoni K. Oppenheim

Backmatter

Additional information