AircraftNews.Com » Environment

Waterbomber sense

mgiles — Sat, 14 Nov 2009 07:26:42 +0000

Canadair Waterbomber

In the recent press it has been announced that the Victorian state Government has engaged the services of a DC 10 water bomber. Little detail has been release on the nature of the arrangements but it is a good start for the introduction of heavy metal into the fire bombing stakes here in Oz. the DC 10 is in the 11000 category simlar to the IL76 gallon but has a pressurized water load and can carry fire retardant which should assist its effectivness. A lot of observers are seeing the up coming fire season as having the makings of a horror event. It would be good to over react rather than under react. Of the other options, Various people conversant with the 747 have opined that it could easily manage the maneuvering required and the reports of the benefit of the IL76 in the Spanish fires are very enthusiastic. Some water scooping Amphibians would also be pretty good. Let us hope what is available is matched with what is required and the not invented here attitude does not prevail.
We wait with trepidation.

DC 10 Waterbomber

Stealthy Windmills

mgiles — Mon, 02 Nov 2009 08:05:31 +0000

Stealth windmill

‘Stealth’ blades take wind turbines off the radar. It seems nothing is ever simple in these days of environmental concern, technological complexity and growing populations and standards of living. A recent example is the innocent windmill. Some see them as a major answers to major problems. Others see them as bird killers, infra noise generators and a con job that will cost too much and deliver too little. Most likely they will find their place but one problem that snuck up on a lot of us is that they can screw with Domestic aviation radars.
The big, fast-moving blades of modern wind turbines interfere with radar for both planes and ships. But ’stealth’ technology could solve the problem. Nothing is ever simple when building large renewable energy projects. For wind energy – which it is hoped could supply a fifth of the UK’s electricity by 2050 – there are logistical challenges and local aesthetic objections, but also a big technical issue. Any time a developer proposes a wind farm near a flight path, the Civil Aviation Authority (CAA) or the Ministry of Defence (MoD) gets jumpy, because windmills do strange things to radar. The British Wind Energy Association reckons that aviation objections are holding back 6GW of wind energy capacity, or enough to power 3.4m homes. About half of all proposed wind projects in the UK have some sort of aviation issue. But this problem may soon be consigned to history: inspired by stealth warplanes, the windmill manufacturer Vestas has come up with a way to make its turbines and blades almost invisible to radar. Modern windmills are massive structures that
are far better at reflecting radar signals than many of the other objects that a radar might encounter and wish to ignore. In addition, the blade tips of a large wind turbine can reach speeds of up to 200mph, comparable to the speed of a light aircraft. “They appear on a radar display as a radar track and this, from an air traffic controller’s perspective, they think it could be an aircraft and, from an air defence perspective, it means there is unwanted clutter,” says the BWEA’s head of aviation, Nicola Vaughan, who describes radar interference as “the biggest technical barrier for wind farms, without a doubt”. Marine radar operators have problems, too – waves bouncing between windmills and ships can create “ghost images”. Couldn’t planes and boats simply be informed where wind farms are, and give them a wide berth? “It might just work for civil
aircraft,” says Mark Roberts of the defence research company Qinetiq. “But I imagine the CAA wouldn’t be too happy because it would cut across their airspace. And from a defence perspective, the bad guys aren’t
going to play ball.” So the best solution is to make the windmills partly invisible to the radar, by reducing the degree to which they reflect radio waves. Then radar software could filter them out. “Radars have filters in
them that can be set to mask out returns from things like electricity pylons and buildings,” says Steve Appleton of Vestas. “The problem is, if you raise that filter level so you couldn’t see turbines, you wouldn’t see anything else.” Last week, Vestas announced that it had been working on a way to fix this, using radar-
absorbing materials developed by Qinetiq that can be inserted into the blades during manufacture.
He adds: “Vestas gave us a number of criteria when we embarked on this project,” says Qinetiq’s Roberts. “Minimal cost increase, it had to be incorporated as part of their existing manufacturing process, and it had to be of minimal weight impact.” The radar-absorbing material is similar to the composites used in stealth aircraft and, since it is inserted inside the blade, does not change the aerodynamic profile or efficiency of the windmill. In its trial, Vestas replaced one blade of a standard windmill with Qinetiq’s “stealth” blade and
found its radar cross-section was significantly reduced. Vestas plans to carry out a full-scale demonstration next year – with all three blades replaced, and the rest of the structure painted in radar-absorbing material. Appleton insists that the extra costs to a developer should be marginal enough not to put them off buying a
“stealth” turbine. Neither Vestas nor Qinetiq would reveal just how much effect the technology currently has, but Appleton said that, as it gets better, he hopes that a wind farm’s radar footprint could be
reduced by an order of magnitude. Bringing the stealth turbine to market will still require much development work and, mindful of that, the rest of the industry is not sitting in wait. At last week’s BWEA annual meeting, the Department for Energy and Climate Change announced that, along with the wind industry and the Crown Estate, it had awarded £5m to the defence company Raytheon for a project that will examine how to improve radar software. “We’d like to make the radar more intelligent so it can differentiate between a radar return from a turbine and one from an aircraft,” says Vaughan.
Step by step, tackling the radar problem from both ends, that 20% target for wind by 2050 doesn’t look so hard after all.

Open Rotor on the Roster?

mgiles — Sun, 25 Oct 2009 02:41:46 +0000

Open Rotor

Recently a student asked me what an open Rotor was and I replied it was basically a turbo prop but with things being how they are a sexier name had to be invented so they came up with this. It got me to thinking; as we are progressively backed up against the wall by reality it is only a matter of time before the open rotor makes its reappearance and so it is timely to have a look at how accurate my glib explanation was. Basically the problem with propellers is that they suffer from severe efficiency losses as the speed of the propeller tips approaches the speed of sound and basically the advantage of them is that they have to accelerate the working fluid (the air they fly in) less because they accelerate a lot more of it. I.e. they have in effect a much greater by-pass ratio than Turbo fans. The big question is where is the best trade off for speed versus efficiency. Time will tell. the Russian Bear long range patrol aircraft with its huge counter rotating props has been with us for years and conferred enormous range advantages when compared with the turbo jets of the time albeit with a considerable disadvantage in reliability. The new A400 European Military lifter will set new standards of frugality and is forecast to cruise at 450 kts which is quite respectable. After the next round of geared fans it looks as it there is only one place to go and that is the Open Rotor. Look for it in the next new wave; maybe with a blended body conformation aircraft.
OPEN ROTOR: HOW DOES IT WORK?
An open rotor engine is essentially a turboprop with two rows of blades, or propellers, which can operate efficiently at higher speeds than a conventional turboprop. The blades of a turboprop tend to spin air out, rather than pushing it back. In an open rotor engine, the forward propeller pushes the air backwards, while the rear one sucks it. “You actually entrain the air in between the two sets of blades, and you can think of it as a virtual fan case,” says Nuttall. “It’s actually stopping the air going out, and the second one straightens up the air from the first one. Most of the air is doing just what it does in a turbofan, hence you can go a lot faster. You can’t go as fast as a turbofan. We think the most efficient speed is about 0.76 Mach.” This compares to around M0.845 for typical jet-powered airliners. A turboprop engine would also need blades twice the diameter of its open rotor equivalent to produce the same power. “There are only two efficiencies in an engine,” says Nuttall. “There’s thermal efficiency, which is how efficiently you get the energy out of the fuel and turn it into ‘turning’. And there’s propulsive efficiency, which is how efficiently you take that energy and turn it into ‘push’.” In a conventional turbofan, propulsive efficiency increases as cruise speed goes up. A single propeller can provide 90-92% propulsive efficiency, but this drops off with speed. “The trick is to try to get an efficiency of that nature, but at [a turbofan] sort of speed, and that’s why you put one [propeller] behind the other. That entrains the air and lets you actually drive the aircraft forward at a mach number of 0.75-0.8,” says Nuttall. In terms of lifecycle costs, an open rotor has no nacelle, thrust reverser, or fan case. “It’s an interesting debate at the moment,” says Nuttall. “When we’re asked this by customers our basic rule of thumb is that it should be about the same as today. You’ve deleted a lot, but you have added complexity at the back. The main complexity you’ve added is the gearbox, but the gearbox is half the power of the [P&W] geared turbofan. We accept that the gearbox is a significant thing that we’ve got to develop, and we’ve got plans for that.” An open rotor would operate at constant torque, with the pitch of its blades and speed of its rotors controlled by a full-authority digital engine control to provide the thrust demanded by the pilot.

Open Rotor Airliner proposal

See http://www.flightglobal.com/articles/2009/10/06/332991/open-rotor-how-does-it-work.html

NASA Targets Turbulence

mgiles — Fri, 10 Jul 2009 04:30:49 +0000

Thunderstorms

A new system to help guide pilots away from severe storms and turbulence in remote ocean regions is being developed at the National Center for Atmospheric Research (NCAR) in Boulder, Colo., NASA said this week. NASA is funding the development of a prototype that should be ready for testing next year. The system combines satellite data and computer weather models with artificial intelligence techniques to identify and predict rapidly evolving storms and other potential areas of turbulence. “Turbulence is the leading cause of injuries in commercial aviation,” said John Haynes, program manager at NASA headquarters, in Washington. “This new work to detect the likelihood of turbulence associated with oceanic storms using key space-based indicators is of crucial importance to pilots.” Turbulence has been cited widely as a possible factor in the recent loss of Air France 447 in the Atlantic Ocean, but it is not yet clear what role, if any, it played in that accident.

The prototype system will identify areas of turbulence in clear regions of the atmosphere as well as within storms. Pilots on selected transoceanic routes will receive real-time turbulence updates and provide feedback. When the system is finalized, it will provide pilots and ground-based controllers with text-based maps and graphical displays showing regions of likely turbulence and storms, NASA said. “Pilots currently have little weather information as they fly over remote stretches of the ocean, which is where some of the worst turbulence occurs,” said scientist John Williams, one of the project leads at NCAR. “Providing pilots with at least an approximate picture of developing storms could help guide them safely around areas of potentially severe turbulence.” Click here for the full NASA news release, which includes to a link to related graphics.
From Avweb http://www.avweb.com/eletter/archives/avflash/1411-full.html#200686

NASA Press release: 09-154

NASA Research to Help Aircraft Avoid Ocean Storms, Turbulence

WASHINGTON — NASA is funding the development of a prototype system to provide

aircraft with updates about severe storms and turbulence as they fly across remote

ocean regions.

Scientists at the National Center for Atmospheric Research (NCAR) in Boulder,

Colo., in partnership with colleagues at the University of Wisconsin, are

developing a system that combines satellite data and computer weather models with

cutting-edge artificial intelligence techniques. The goal is to identify and

predict rapidly evolving storms and other potential areas of turbulence.

“Turbulence is the leading cause of injuries in commercial aviation,” said John

Haynes, program manager in the Earth Science Division’s Applied Sciences Program at

NASA Headquarters in Washington. “This new work to detect the likelihood of

turbulence associated with oceanic storms using key space-based indicators is of

crucial importance to pilots.”

The system is designed to help guide pilots away from intense weather. A variety of

NASA spacecraft observations are being used in the project, including data from

NASA’s Terra, Aqua, Tropical Rainfall Measuring Mission, CloudSat and CALIPSO

satellites.

The prototype system will identify areas of turbulence in clear regions of the

atmosphere as well as within storms. It is on track for testing next year. Pilots

on selected transoceanic routes will receive real-time turbulence updates and

provide feedback. When the system is finalized, it will provide pilots and ground-

based controllers with text-based maps and graphical displays showing regions of

likely turbulence and storms.

“Pilots currently have little weather information as they fly over remote stretches

of the ocean, which is where some of the worst turbulence occurs,” said scientist

John Williams, one of the project leads at NCAR. “Providing pilots with at least an

approximate picture of developing storms could help guide them safely around areas

of potentially severe turbulence.”

NCAR currently provides real-time maps of turbulence at various altitudes over the

continental United States. Williams and his colleagues are building on this

expertise to identify turbulence over oceans. The team has created global maps of

clear air turbulence based on global computer weather models that include winds and

other instabilities in the atmosphere. Drawing on satellite images of storms, the

scientists also have created global views of the tops of storm clouds. Higher cloud

tops often are associated with more intense storms, although not necessarily with

turbulence.

The next step is to pinpoint areas of possible turbulence within and around intense

storms. The team will study correlations between storms and turbulence over the

continental United States, where weather is closely observed, and then infer

patterns of turbulence for storms over oceans.

In addition to providing aircraft and ground controllers with up-to-the-minute maps

of turbulence, the NCAR team is turning to an artificial intelligence technique,

known as “random forests,” to provide short-term forecasts.

Random forests, which have proven useful for forecasting thunderstorms over land,

consist of many decision trees that each cast a yes-or-no “vote” on crucial

elements of the storm at future points in time and space. This enables scientists

to forecast the movement and strength of the storm during the next few hours.

“Our goal is to give pilots a regularly updated picture of the likely storms ahead

as they fly over the ocean, so they can take action to minimize turbulence and keep

their aircraft out of danger,” explained NCAR scientist Cathy Kessinger, a project

team member.

The NCAR project is funded by NASA’s Applied Sciences Program, which seeks to

translate NASA’s investment in Earth observations into applications that address

real problems. The program and its partners are working to bridge the gap between

research results and operational aviation weather products in such areas as in-

flight icing, convective weather, turbulence, volcanic ash and space weather.

For images related to this turbulence prototype system, visit:

http://www.nasa.gov/topics/earth/features/turbulence.html

First Fuel Cell powered Aircraft takes to the Air

mgiles — Wed, 08 Jul 2009 07:52:01 +0000

Antares DLR H2

On 7th July a highly modified Antares Motor glider took to the air under the power of an electric motor driven by a hydrogen and oxygen powered fuel cell.
The electric motor has a maximum power of 25 Kw and an over all propulsion efficiency of 52% in the cruise and 44% in the climb. It has a range of about 750 km and a maximum level cruise of 170 kph.
The aircraft is a significantly modified Antares Glider constructed by the Lange company and is manufactured from state of the art composites with input from the DLR (Deutsches Zentrum fur Luft und Raumfahrt) BASF Fuel Cells and Serenergy Denmark.
The Antares DLF H2 is configured in the more or less standard motor glider manner with a pusher propeller mounted above the fuselage behind the single pilot seat cockpit with the Hydrogen fuel in one pod slung under the Port wing and the Fuelcell reactor slung under the other.
It emits no CO2 and is almost silent. If the hydrogen is obtained from renewable sources no CO2 is produced at any point in the energy chain of the flight.

Antares DLR H2

For full details go to the DLF portal web site http://www.dlr.de/en/desktopdefault.aspx/tabid-1/86_read-18278/

Time for a Radical Change

mgiles — Sat, 20 Jun 2009 02:47:27 +0000

Blended body concept

Some years ago (maybe 30) I read in Flight that the time was coming when a latest generation Combat aircraft was going to take the entire GDP of a small nation. At the time I took it seriously and though it a bit of an exaggeration but as time has worn on it seems they were joking at the time using delightful British irony but that they had unwittingly hit the nail on the head. That day is here with the F22 that the US wont sell to any one because it cost them so dear and mega Airliners taking many Billions to create and 100s of millions to buy.

Blended body plan

As the financial crisis looms and doomsayers prattle away I wonder whether now is the time for a paradigm shift. Skip the A380 and A350 and B787 etc and go for a highly standardized no frills blended body well and truly subsonic alternatively powered (fuel cells and props?) solutions that will halve the cost per kg per kilometer (Note I use metric as I am talking of the future)
Anyone with the courage to do it should (?!) clean up.

Oz Gov calls for Aviation CO2 controls

mgiles — Wed, 17 Jun 2009 03:56:14 +0000

The prospect of a worldwide carbon tax for airline passengers is gathering pace after the Australian government demanded the inclusion of the aviation industry in the global climate change treaty.

The Australian administration has proposed that airlines are set a carbon dioxide reduction target as part of the treaty that will emerge from the Copenhagen summit this year. The latest plan would see responsibility for any aviation deal handed over to the UN Framework Convention on Climate Change, which is overseeing the treaty talks.

The proposal is one of four suggestions for dealing with aviation emissions that will be discussed in Copenhagen. If the Australian plan is accepted, it is likely that airlines will join a global emissions trading scheme. British Airways backed a global scheme last week and its chief executive, Willie Walsh, said it would force up fares as airlines pass on the multibillion-dollar cost of acquiring carbon credits.

Under a carbon trading scheme, airlines would be set an emissions limit – for instance, no more than 97% of the total amount of carbon dioxide emitted by carriers in 2005 – and would be given free carbon credits equivalent to 85% of that total. The rest would be acquired in an open auction, with the proceeds being handed to developing countries.

The Australian proposal is gathering momentum because the body representing airlines at the talks is struggling to form its plan due to internal wrangling.

Environmental campaigners welcomed the Australian proposal. Joss Garman, of Greenpeace, said: “Scientists project that unless world leaders take action, ships and planes would eat up 50% to 80% of the world’s carbon budget by 2050, making it essential that governments end these industries’ special treatment and include them in a strong Copenhagen treaty.”
From http://www.guardian.co.uk/business/2009/jun/14/airlines-emissions-trading-australia

Wind Farms block Aircraft from Radar

mgiles — Mon, 25 May 2009 06:38:31 +0000

The body that monitors UK airspace is seeking a solution to the potentially disastrous problem of commercial and military aircraft disappearing in radar blackout zones caused by wind farms.

National Air Traffic Services (Nats) has asked Raytheon, the American defence company, to design the world’s first system for allowing radar to see through wind farm interference.

The cost of the £5 million project is expected to be picked up by the wind energy industry.

Wind farm turbines create a Doppler effect as they turn, which shows up on radar screens. As the area and number of these wind farms has increased, the number of radar blackout zones has also risen. Aircraft passing through the area can disappear in the blackout and air traffic controllers can lose their exact position.

The Royal Air Force is concerned that enemy bombers or other aircraft could hide behind interference from offshore wind farms and approach Britain undetected.

A Nats spokesman said: “We have a duty to safeguard our operations, so in the past we have objected to the development of a number of wind farms that threaten aircraft safety. We need a system that can eliminate this problem.”

Raytheon has been asked to create a software system that will filter out the wind farm noise from other radar signals. This will effectively allow air traffic controllers to see through the wind farms. The company, which is the largest manufacturer of radar systems in the world, hopes to complete the project by the end of next year. Once completed, it will also be deployed in the Netherlands.

Andy Zogg, vice-president of command and control systems at Raytheon, said: “As the number of wind farms grows, there are more and more of these radar black holes. They show up as clutter on the radar screen and the concern is that aircraft approaching from behind the turbines or flying over them cannot be seen.”

Brian Smith, general manager of Raytheon Canada, said: “Our work will be to develop the algorithms that allow us to discriminate between turbines and aircraft. It is called clutter erasure.”

The Government has identified wind power as a key to reducing reliance on carbon dioxide producing energy sources.

Europe’s largest onshore wind farm opened last week at Whitelee in Scotland. The 140 turbines cover an area of 55 square kilometres and are each 110 metres high. The wind farm will generate enough electricity to power 250,000 homes.

From http://business.timesonline.co.uk/tol/business/industry_sectors/transport/article6355764.ece