Environmental Engineering Reference
In-Depth Information
• Last minute changes in infrastructure posing hazards to operation, e.g., weather
advisories;
• Introduction of free flying areas; and
• New policies at airports.
In Europe, people have a great sensibility to noise. However, there are other
regions in the world whose habitat do not have such high requirements for noise
emissions. The further decrease of pollutant emissions and noise will raise costs,
because positive results usually require a cost-intensive and long development
phase. New turbofan and propfan engines will produce less noise in comparison
with older propeller and turboprop or turbofan engines.
At the start of the twenty-first century, consolidation in the aviation industry has
meant that only a few manufacturers have kept producing commercial passenger
airplanes. However, tendencies are proving that new manufacturers in several
countries will independently start producing modern airplanes in the next years
and decades.
Can nuclear power replace oil? There were projects with nuclear-powered
airplanes in the Soviet Union, the USA, and Great Britain at the beginning of the
1950s. The hopes of these projects could not be achieved because of economic,
technical, environmental, and security reasons. It is not expected that nuclear-
powered airplanes will be developed in the future.
Dirigibles are lighter than air. Modern industrial types transport heavy minerals
or other raw materials from inaccessible areas to processing plants. The current
models can carry a payload of 40 t (39 lnt, i.e. 88 360 lb) up to 360 km
(194.4 nmi) [
64
].
17.4.3 Future Ship Technology
The slow speed two-stroke marine diesel engine will certainly consolidate its
leading position with its optimal thermal effectiveness, resistance to wear, and high
durability. It converts more than 50% of the chemical and thermal energy to
mechanical work because of its high thermal efficiency. Theoretically more than
60% thermal efficiency is possible. However, higher heat recovery is not possible
currently because the exhaust gas heat is used to produce steam, hot water and
fresh water, and to warm the air in the intake which lowers the real thermal
efficiency of engine.
In the future, the power of the engine will assumebly increase. Considerable
potential is still available in the application of new materials in the combustion
chamber and in the turbocharger. This development also presupposes an improve-
ment in environmental compatibility and in climate balance of new materials.
Currently, the highest concentrations of pollutants exist in the exhaust gas of
HFO fuel. However, the change between current HFO to higher fuel qualities,
especially to diesel oil, may show incompatibility in the following way in the future:
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