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Тема |
Хора бачкат и в това поле, да... [re: Св. Скромни] |
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Автор |
Св. Скромни () |
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Публикувано | 03.07.00 22:39 |
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От Междумрежие стоянката на ДелтаЯстреб (DeltaHawk):
Benefits of the diesel-cycle engine include:
Desirable Fuel Type: Low flammability and worldwide availability
of Jet-A or diesel fuel is valued in all applications; current
aviation fuel for the IO-360 and other high compression engines
is leaded and will eventually be made unavailable by the EPA
(Environmental Protection Agency), making those engines unusable.
Fuel Efficiency: The DeltaHawk is designed to BSFC (brake specific
fuel consumption) of .38 lb/hp/hr versus current avgas-powered aviation
engine book BSFC of .59 lb/hp/hr at 75% and above.
Lower Fuel Cost: 20-30% more range per gallon. Also, cost per
gallon of Jet-A averages $0.09 less than 100LL aviation fuel in
the U.S. The price differential is much greater in Europe.*
Electromagnetic Noise Elimination: Absence of an ignition system
reduces interference with navigational and communication systems;
for military applications, this is desirable for tactical reasons.
Simplicity of Operation: Single-lever power operation
(no mixture control).
Durability: Inherent in diesels because diesel and jet fuels provide
more lubricity and because no electrical system (magnetos or electronic
ignition)is required.
* As a recent e-mail stated: "In Europe and particularly the U.K.
economic benefits are more pronounced due the prohibitive price of
both petrol and avgas ... Jet A ... does not cost more than Ј0.30
per litre ($0.45) as opposed to petrol or avgas at Ј0.80 per litre
($1.28). Also given the improved economy of your engine it is not
difficult to show a saving of Ј5000.00 ($8000.00) per year in fuel
on only 210 hours engine time. Conservative hourly savings work out
at Ј25.00 per hour ($40.00) in a Velocity or Cozy MK4. Ј100.00
($160.00) of fuel will carry you 2100nm with the DeltaHawk or 630nm
with the Lycoming 360. While in practice these saving may not be
quite so large they will still be considerable, probably over 50%.
... The incredible savings this side of the water would probably
make conversion from other engine types a very real economic
proposition even with the cost of a new engine!!"
Some further benefits from the particular DeltaHawk
design decisions for our V-4 Turbo Diesel engine:
Smoothness: A two-cycle diesel has four power pulses per revolution
with continuous positive torque applied to the propeller (versus two
pulses per revolution with approximately 30 degrees of negative torque
in four-cycle/four-cylinder engines).
Liquid-Cooling: Reduces overcooling in descents from altitude.
Also, reduced thermal variance in operation allows tighter
manufacturing tolerances, leading to increased power and fuel efficiency.
Durability: (1) The 2-cycle piston-ported design reduces the parts
count by eliminating valves, valve train and cam shaft; (2) liquid
cooling reduces fatigue; (3) unified cylinder and block design
eliminates studs, gaskets and bolts.
Reliability: Fail-safe design aspects have been incorporated,
including backup air, redundancy of fuel pumps and limited operation
at reduced power without coolant.
Small Size and Light Weight: The V-design is stout and compact; use of
advanced materials and focus on low weight as a design criteria will
result in a V-8 model producing nearly 1 horsepower per pound. The V-4
is at least 60 lbs lighter than the equivalent aviation engine (comparisons
at fully installed weight) and hundreds of pounds lighter than equivalent
marine diesels. For new aircraft designs, the V configuration also allows
a more rounded cowling, permitting aerodynamic and propeller noise reduction
improvements.
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