Recent legislative pressures aimed at improving the environment
together with an escalation in fuel prices have rendered the diesel
engine the optimum prime mover in the Commercial Vehicle Market. In
turn, the diesel has been the subject of intensive development.
However, such is the magnitude of these pressures that development
has often been aimed at isolated features of the engine, the
outcome being an imbalance between sometimes conflicting operating
parameters. This paper discusses the development of the high speed
diesel engine across a wide front, establishing the improvements in
terms of overall vehicle performance and environmental
acceptability.
A scenario of the success of the diesel engine in the commercial
vehicle sector is presented. This highlights the superior
efficiency of the diesel engine relative to the gasoline
alternative, which has been primarily responsible for the
diesel's penetration in the commercial vehicle market.
The various parameters which have been subject to development
are discussed on a inter-related basis. Technical and quality
improvements associated with smoke compliance are discussed, along
with the latest developments on emission control. Consideration is
given to the continued enhancement of power within the confines of
environmental legislation. Advances made in turbocharger matching
within the restraints of cost relative to the engine family
concept, ensure that vehicle flexibility is maintained at the high
power. Short and long term approaches to noise reduction, together
with factors that minimise total installation noise are
presented
The relationship between engine life and load factor is explored
for varying types of vehicle usage, to establish design parameters
and duty cycles. These relationships are further developed by the
utilisation of computer techniques that ensure option
engine/vehicle matching, relative to gross vehicle weight,
transmission and frontal area.
It is concluded that continued refinement of the diesel engine
and its matching to the commercial vehicle will result in extended
life, improved fuel economy and a more socially acceptable
product