Sách Part 1 Theory

The theory of
compression
ignition engines

Contents
1.1 Introduction
1.1.1 Historical
1.1.2 Classifications
1.2 Two-stroke and four-stroke engines
1.2.1 Two-stroke engines
1.2.2 Four-stroke engines
1.2.3 Evaluation of power output of two-stroke
and four-stroke engines
1.2.4 Other operating parameters
1.3 Air standard cycles: constant pressure—constant
volume—dual combustion
1.3.1 Theoretical expressions for air standard
cycles
1.3.2 Further comments on air standard cycles
1.4 Basic thermodynamics of real gases
1.4.1 Gas properties
1.4.2 Combustion
1.4.3 Dissociation and reaction kinetics
1.5 Real diesel engine cyclic processes
1.5.1 Closed period
1.5.2 Open period
1.6 Detailed cycle analysis methods
1.6.1 Closed period
1.6.2 Open period (gas exchange process)
1.6.3 Completion of calculation sequence
References

1.1 Introduction
1.1.1 Historical
Although the history of the diesel engine extends back into the
closing years of the 19th century when Dr Rudolf Diesel began
his pioneering work on air blast injected stationary engines, and
in spite of the dominant position it now holds in many applications,
e.g. marine propulsion and land transport, both road and rail, it
is today the subject of intensive development and capable of
improvements. These will guarantee the diesel engine an assured
place as the most efficient liquid fuel burning prime mover yet
derived.
Before 1914, building on the work of Dr Rudolf Diesel in
Germany and Hubert Akroyd Stuart in the UK, the diesel engine
was used primarily in stationary and ship propulsion applications
in the form of relatively low speed four-stroke normally aspirated
engines.
The 1914-18 war gave considerable impetus to the develop-
ment of the high speed diesel engine with its much higher specific
output, with a view to extending its application to vehicles.
Although the first generation of road transport engines were
undoubtedly of the spark ignition variety, the somewhat later
development of diesel engines operating on the self or com-
pression ignition principle followed soon after so that by the
mid 1930s the high speed normally aspirated diesel engine was
firmly established as the most efficient prime mover for trucks
and buses. At the same time with the increasing use of
turbocharging it began to displace the highly inefficient steam
engine in railway locomotives while the impending 1939-45
war gave a major impetus to the development of the highly
supercharged diesel engine as a new aero engine, particularly in
Germany.
Since the 1939-45 war every major industrial country has
developed its own range of diesel engines. Its greatest market
penetration has undoubtedly occurred in the field of heavy road
transport where, at any rate in Europe, it is now dominant. It is
particularly in this field where development, in the direction of
turbocharging in its various forms, has been rapid during the
last twenty years, and where much of the current research and
development effort is concentrated. However, a continuous
process of uprating and refinement has been applied in all its
fields of application, from the very largest low speed marine
two-stroke engines, through medium speed stationary engines
to small single cylinder engines for operation in remote areas
with minimum attendance. There is little doubt that it will continue
to occupy a leading position in the spectrum of reciprocating
prime movers, so long as fossil fuels continue to be available
and, provided it can be made less sensitive to fuel quality, well
into the era of synthetic or coal derived fuels.



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