Monday, August 29, 2011 9:39 AM
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Một công ty ở California đang thực
hiện một phương tiện vận chuyển hàng hóa mới và sau này có thể
chở hành khách. Nó không phải là máy bay và cũng không là
khinh khí cầu, nhưng mang nhiều nét của cả hai. Sử dụng công
nghệ mới, nó sẽ phục vụ ngành thương mại và quân
sự.
Phương
tiện chuyển vận mới của công ty Aeros được gọi là Aeroscraft,
được thiết kế để chở hơn 50 tấn hàng hóa và giao hàng xa hàng
vạn cây số.
Một mô hình để giới thiệu đang
được xây dựng bên ngoài Los Angeles, có sự tài
trợ của Bộ quốc phòng Mỹ. Chiếc
Aeroscraft thử nghiệm này dài 75 mét và rộng 30 mét, và sẽ sẵn
sàng để bay vào cuối năm
tới.
Ông Edward Pevzner của công ty
Aeros cho biết:
“Nó sẽ tới được những nơi khó tiếp cận. Ví dụ bắc Canada và
Alaska, nơi đang có các dự án thăm dò dầu
khí lớn. Nó cũng tới được khu vực Amazon hay châu
Phi, những nơi kém phát triển."
Kỹ sư hàng không Tim Kenny nói chìa khóa của con tàu là một công nghệ mới cho phép nó lên xuống mà không cần bớt hoặc thêm trọng lượng, giống như các khinh khí cầu thông thường. Không giống như khinh khí cầu, nó không đòi hỏi phải có nhân viên dưới mặt đất. Và không giống như khinh khí cầu, không phải lúc nào nó cũng nhẹ hơn không khí.
Ông Kenny cho biết đôi khi nó nhẹ hơn và đôi khi nặng hơn không khí xung quanh:
“Toàn bộ con tàu sẽ được bơm đầy khí helium , và sau đó bên trong nó, chúng tôi sẽ có các hệ thống phao nổi có thể biến đổi.”
Helium giúp nâng con tàu lên, và khi helium được nén lại, tàu sẽ mất sức nổi và có thể đáp.
Kiểm soát và lực đẩy là do các động cơ cánh quạt chạy bằng nhiên liệu máy bay.
Ông Kenny cho biết nhờ có công nghệ mới, tàu vừa có cơ cấu rắn nhắc vừa nhẹ cân:
“Các tiến bộ về sản xuất vật liệu tổng hợp đã thực sự thúc đẩy và di chuyển ngành này theo hướng xa hơn. Chúng tôi đã kết hợp vật liệu tổng hợp với nhôm, và chế được các thành phần cấu trúc con tàu thật nhẹ."
Nếu nó được diễn tiến theo kế hoạch, loại tàu tương tự nhưng lớn hơn có thể có mặt trên thị trường trong một vài năm.
Quân đội Mỹ chú ý đến tiềm năng của tàu. Các công ty tư nhân cũng thế. Ứng dụng thương mại của nó bao gồm di chuyển các tua-bin đến các trại gió, trước đây vẫn nghĩ là khó tiếp cận, để tạo ra điện năng cho khắp một thị trấn.
Công ty cho biết một khi tàu đã chứng minh vận chuyển được hàng hóa một cách hiên ngang, các phiên bản cải biên cũng có thể được xây dựng để vận chuyển hành khách.
Mike O'Sullivan
Los Angeles, CA
How the Aeroscraft Will Work
The Aeroscraft is a heavier-than-air vehicle currently in development for use in the near future -- a prototype should be finished by 2010. It will be able to haul massive amounts of cargo and transport hundreds of passengers in luxury with quiet, electric engines. It will also be able to take off and land without an airstrip. The Aeroscraft is sort of a hybrid -- it carries helium, like a blimp, but its shape provides lift, like an airplane. In this article, we'll see how the Aeroscraft flies and what it will be able to do.
Image
courtesy Worldwide Aeros Corp.The
Aeroscraft
Passenger travel and shipping by airship died out in the late 1930s, after the infamous Hindenburg disaster. Since then, lighter-than-air craft have been used mainly for advertising or to provide aerial views for television cameras. In recent years, several companies have been introducing safer, more efficient airships to the world. These companies include the Zeppelin Company, makers of the Hindenburg, and Worldwide Aeros Corp, designers of the Aeroscraft.
A lighter-than-air craft, such as an airship (or blimp), is filled with a gas, such as helium or hydrogen, which provides buoyancy. Buoyancy is the effect of something rising up in relation to a heavier substance surrounding it. Air is lighter than water, so if you fill an inflatable ball with air, it will float in a swimming pool. The same thing happens with helium or hydrogen -- they're both lighter than air. (To learn more about how blimps fly, check out How Blimps Work.) A regular airplane is much heavier than air, so lift must be provided by some other means. Lift is a force on a wing immersed in a moving fluid (in this case, air), and it acts perpendicular to the flow of the fluid. When the plane moves through the air at sufficient speed, the deflection of air creates lift. This is a very basic explanation; check out How Airplanes Work for more detail about how lift is created.
Image courtesy Worldwide Aeros Corp. The major
parts of the Aeroscraft
The Aeroscraft combines elements of a lighter-than-air craft with those of an airplane. It holds 14 million cubic feet of helium, which negates about 60 percent of the craft's weight [ref]. When the Aeroscraft is at cruising speed, its aerodynamic shape, as well as canards (forward fins) and empennages (aft, or rear fins), provide the remaining lift. That's pretty impressive when you consider the Aeroscraft's size: 165 feet high, 244 feet wide and 647 feet long. That's about as long as two football fields. It will carry up to 400 tons of cargo over a range of 6,000 miles. With a top speed of 174 mph, it will be able to cross the U.S. in about 18 hours [ref].
Operating the Aeroscraft
The Aeroscraft can take off and land vertically using six turbofan jet engines, thanks to an emergent technology called Dynamic Buoyancy Management. This capability will allow it to fly to and from areas without an extensive transportation infrastructure. Once the craft reaches cruising altitude (around 8,000 feet), giant aft propellers will move it forward, and the Aeroscraft's aerodynamic shape will generate enough lift to keep it in the air. Hydrogen fuel cells or another form of environmentally friendly fuel will fuel the electric propellers. This means the Aeroscraft will be both efficient and quiet.
Image
courtesy Worldwide Aeros Corp.
On the Aeroscraft, the four canards and two empennages will keep it stable and allow the pilot to make minor adjustments to keep it flying level. Outside conditions, such as wind and air pressure, will be measured along with weight distribution inside the craft. If all the passengers suddenly run to the port side of the craft to see something, the control system can compensate for that. Air from outside will be sucked into holding tanks, where it will be compressed and used as ballast.
All pilot control and avionics systems will use Fly-by-Light (FBL) technology. The pilot's commands are fed into a flight control processor and sent to the surface actuators via electrical signals transmitted along fiber optic cables. In Fly-by-Wire (FBW) Systems, wires must be shielded from electromagnetic frequency (EMF) interference, which results in additional weight, cost and maintenance. FBL is immune to EMF interference, such as lightning strikes. The FBL, flight control processor and flight control devices make up the Onboard Data Exchange Managing System (ODEMS). This system means that the flight is mostly automated, with the two-person crew monitoring the flight conditions to ensure safety.
The Aeroscraft does not require an extensive ground crew for either takeoff or landing. Its Air Cushion Take-off/Landing System (ACTLS), located on the belly of the aircraft, creates a vacuum to anchor it upon landing. The ACTLS reverses upon takeoff.
Next, we'll look
at proposed uses for the Aeroscraft.
Cruising Speed: 174 mph (78
m/s)
Altitude
Range: 0 to 8,000 ft (0 to
2438 m)
Payload: Up to 250 passengers or 400
tons (362,874 kg) of cargo
Proposed Uses
Designers envision the Aeroscraft
operating like a luxury cruise ship that sails through the air
instead of the ocean. Up to 250 passengers will travel in
comfort and style, with sleeping quarters, restaurants, a
casino and other amenities. The Aeroscraft will be able to
cruise past scenic landmarks to give passengers a stunning
view, even if the landmark is in the middle of a jungle. The
passenger version is the Aeros-ML, which would have a smaller
configuration, with room for about 120 passengers or 20 tons
of cargo.
Image
courtesy Worldwide Aeros
Corp.
The Aeroscraft also has potential as a
cargo ship. There are two versions for freight -- the Aeros-D4
and the Aeros-D8. Currently, time-sensitive cargo is usually
shipped by land because shipping by airplane is
cost-prohibitive and has weight limitations. But the
Aeroscraft's cargo hold of two acres can accommodate 400 to
500 tons of cargo, and it can handle huge items that can't be
disassembled, like oil rigs or huge pieces of factory
machinery. It will be able to move them without disrupting
traffic, and much more quickly than trucks can. Aeroscraft's
designers think it will be able to do so at a competitive
cost. It may even be able to carry "an entire store's worth of
merchandise directly to a Wal-Mart" [ref].
Image
courtesy Worldwide Aeros
Corp.
That kind of cargo capacity interests
the military as well. It could carry an entire company (100 to
200 troops), all of their equipment, all their support troops,
fuel, rations, water and everything else the company would
need to set up and go to work fighting a war, all in an
aircraft that could drop them anywhere. Such a craft could
revolutionize military logistics.
Worldswide Aeros was one of two
companies to receive a $3 million preliminary design contract
to design a vehicle for DARPA's Walrus program. DARPA (Defense
Advanced Research Projects Agency) is the research and
development arm of the U.S. Department of Defense. The Walrus
program was created to develop a large heavier-than-air
aircraft to deploy both military personnel and equipment.
However, the project is currently without government funding,
and DARPA's budget request for the 2007 fiscal year called to
terminate Walrus at the end of this developmental phase "in
keeping with congressional intent" [ref]. The company is still moving
forward with its prototype development and plans to have it
ready within 18 months.
Recently, the U.S. Air Force awarded
Aeroscraft with a Phase I Small Business Innovative Research
Program (SBIR) Award. This award "encourages small businesses
to explore their technological potential and provides the
incentive to profit from its commercialization" [ref]. Aeroscraft will use the
award to develop high-altitude, near-space aircraft that can
perform many of the same duties as Earth-orbiting spacecraft
or satellites at a fraction of the cost.
The Aeroscraft
Company also thinks their airship will be perfect for commuter
flights.
According to their Web
site:
For short-haul
markets, The Short Take-Off and Landing ("STOL") capability of
Aeroscraft, its relatively low noise, and efficient fuel
consumption (due to lower power levels) give the Aeroscraft
power advantages. Aeroscraft will be comfortably competitive
in short-haul markets, which have to date been largely
uneconomical for traditional airliners. The airlines have
largely abandoned service routes between 20 and 300 miles, but
Aeroscraft could operate profitably in these markets, restore
service between city centers and even minor airports, and work
as a feeder to international airports and
hubs.
Some other suggested uses:
Agriculture and
Environmental - An Aeroscraft could carry a huge amount of
water to dump on a fire in
a remote location. It could also deliver fertilizer and assist
in identifying sources of pollution.
Disaster relief
- In the wake of a natural disaster, the lack of
infrastructure can make it very difficult to bring in aid
supplies in large quantities. The Aeroscraft could haul
medical supplies, drinking water and food directly to the
affected areas.
Worldwide Aeros
plans to have a prototype Aeroscraft ready for testing by
2010. It's too early in the development stage to know how much
it will cost to manufacture an Aeroscraft. However, the
company claims that they will cost 30 percent less in capital
costs and 50 percent less in maintenance costs than
conventional aircraft [ref]. Two companies have already
signed agreements to receive the first Aeroscrafts when it is
ready for commercial production.
Image
courtesy Worldwide Aeros
Corp.
The Aerostat, a tethered balloon system
made by Worldwide Aeros
Worldwide Aeros
Corporation
The company now known as
Worldwide Aeros Corporation started out at Aeros, Ltd., a
small company founded in the Ukraine by Igor
Pasternak. After growing up in the city of Lviv,
Ukraine, Pasternak received a Masters degree in
engineering from Lviv Politechnike. After
achieving success with Aeros, Ltd. in developing and marketing
lighter-than-air craft in Europe and
Asia, Pasternak moved the company to New
York in 1992. In 1994, they moved again, to
California, where the company operates today.
Worldwide Aeros Corp designs and manufactures blimps and other
lighter-than-air craft for a wide variety of
uses.
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