This whitepaper explains the process of specifying cable assemblies and will be ideal for Engineers wishing to learn the basics of the process, and as a refresher for the more experienced Engineer. Particular focus is given to sectors that require high-levels of reliability and details the criteria required to ensure a long operational life-span.
Post Syndicated from Payal Dhar original https://spectrum.ieee.org/energywise/aerospace/aviation/could-airships-rise-again
Transportation produces about one-fourth of global anthropogenic carbon emissions. Of this, maritime shipping accounts for 3 percent, and this figure is expected to increase for the next three decades even though the shipping industry is actively seeking greener alternatives, and developing near-zero-emission vessels.
Researchers with the International Institute for Applied Systems Analysis (IIASA) in Austria recently explored another potential solution: the return of airships to the skies. Airships rely on jet stream winds to propel them forward to their destinations. They offer clear advantages over cargo ships in terms of both efficiency and avoided emissions. Returning to airships, says Julian Hunt, a researcher at the IIASA and lead author of the new study, could “ultimately [increase] the feasibility of a 100 percent renewable world.”
Today, world leaders are meeting in New York for the UN Climate Action Summit to present plans to address climate change. Already, average land and sea surface temperatures have risen to approximately 1 degree C above pre-industrial levels. If the current rate of emissions remains unchecked, the Intergovernmental Panel on Climate Change estimates that by 2052, temperatures could rise by up to 2 degrees C. At that point, as much as 30 percent of Earth’s flora and fauna could disappear, wheat production could fall by 16 percent, and water would become more scarce.
According to Hunt and his collaborators, airships could play a role in cutting future anthropogenic emissions from the shipping sector. Jet streams flow in a westerly direction with an average wind speed of 165 kilometers per hour (km/h). On these winds, a lighter-than-air vessel could travel around the world in about two weeks (while a ship would take 60 days) and require just 4 percent of the fuel consumed by the ship, Hunt says.
ZeroAvia says electric efficiency, fewer repairs, and onsite hydrogen production can make zero-emissions flight cheaper than burning jet-fuel
Post Syndicated from Payal Dhar original https://spectrum.ieee.org/energywise/aerospace/aviation/rooftop-solar-refinery-produces-carbonneutral-fuels
Scientists in Switzerland have demonstrated a technology that can produce kerosene and methanol from solar energy and air
Scientists have searched for a sustainable aviation fuel for decades. Now, with emissions from air traffic increasing faster than carbon-offset technologies can mitigate them, environmentalists worry that even with new fuel-efficient technologies and operations, emissions from the aviation sector could double by 2050.
But what if, by 2050, all fossil-derived jet fuel could be replaced by a carbon-neutral one made from sunlight and air?
In June, researchers at the Swiss Federal Institute of Technology (ETH) in Zurich demonstrated a new technology that creates liquid hydrocarbon fuels from thin air—literally. A solar mini-refinery—in this case, installed on the roof of ETH’s Machine Laboratory—concentrates sunlight to create a high-temperature (1,500 degrees C) environment inside the solar thermochemical reactor.
Cape Air recently ordered the Eviation “Alice” battery-powered, 9-seat regional aircraft—pointing toward aviation’s e-future
Commercial electric aviation took its first steps forward last month when a Massachusetts-based regional airline announced the first order of the first all-electric passenger airplane. The “Alice,” a three-engine, battery powered airplane with a 1000-kilometer range on a single charge, is slated to be delivered to Cape Air airlines for passenger flights in 2022.
The Alice, manufactured by Kadima, Israel-based startup company Eviation, has not yet been certified by the U.S. Federal Aviation Administration. However, the company’s e-airplane “could be certified right now to fly,” insists Lior Zivan, Eviation’s CTO. “It does not need a major rewrite of the rules to get this in the air,” he says.
Zivan says the company is “anticipating full certification by 2022.”
The Alice, Zivan says, will be powered by a 900-kilowatt-hour (kWH) lithium ion battery manufactured by South Korean battery maker Kokam Battery. (For comparison, the Tesla Model 3 electric car uses a 50- to 75-kWH battery pack, according to a 2017 investor call from company CEO Elon Musk.)
Cape Air is a Northeast regional airline that flies to Cape Cod, Martha’s Vineyard, Nantucket, and numerous other vacation and regional destinations. According to Trish Lorino, Cape Air vice president of marketing and public relations, the company’s historic order of Eviation’s Alice aircraft “makes sense for us because we are a short-haul carrier.” Lorino notes that, “For 30 years, we have specialized in serving short-haul routes, particularly to niche and island destinations.”
According to Cape Air’s website, the carrier currently operates 88 Cessna 402s (which seat 6 to 10 passengers) and 4 Islander planes (9-seat capacity) made by the British company Britten-Norman. The 9-seater Alice e-aircraft thus fits within the Cape Air fleet’s general size and passenger capacity.
Lorino says that although the carrier has not yet decided which routes will feature the Alice, company officials currently anticipate that e-flights will cover routes that keep the plane close to the company’s Massachusetts headquarters. “Short-haul routes ‘in our backyard’ such as Nantucket, Martha’s Vineyard, and Provincetown would be the likely routes,” she says.
Bar-Ohay’s remarks at the Show highlighted the differences inherent in designing and engineering an all-electric airplane and a conventional, petroleum-fueled plane. As he pointed out, the Alice has a maximum takeoff weight of 6,350 kilograms (14,000 pounds), but 3,700 kg of that is the battery. (And of course there is no fuel burned, so its takeoff weight is more or less its landing weight.)
Each of the Alice’s three motors, according to Zivan, has one moving part. “A similar [petroleum-fueled] reciprocating engine has about 10: six pistons, a crankshaft, oil pump, and a two-shaft gearbox,” Zivan says. “Obviously, electric propulsion has a major advantage in both reliability and maintenance.”
There are redundant systems in the Alice, Zivan says, in both the propulsion and the battery assembly. The e-aircraft’s three engines (two “pusher” motors mounted at the rear ends of the two wingtips and another “pusher” motor mounted at the rear of the plane) have, he says, “mostly dual and for some components triple [redundancy].”
As for the electrical system, Zivan says, “The battery assembly is redundant in many levels, starting at the parallelism of the cells and ending at the number of in-series cells branches. The battery is designed in such a way that any malfunction or failure will result in a minimal reduction in the capacity if any.”
Because Alice doesn’t burn any fuel in flight, and relies only on cheaper electric charge, the cost of operating the plane is expected to be lower than its petroleum-fueled counterparts. And the noise emitted by a plane with no internal combustion engines is also lower; this is especially true for Alice, given its ability (unique to e-aircraft) to vary its propeller speeds to compensate for crosswinds and to lower cabin noise.
As an early standard-bearer in electric passenger flight, Cape Air says its decision to purchase Alice (the number of electric aircraft that will join its fleet has not been finalized) was also partly motivated by the company’s “deep sense of social responsibility,” Lorino says. (The company’s headquarters is 100-percent solar powered, she says, and the company is now hoping to use sustainable energy sources for charging its fleet of e-airplanes.)
“Our hope is that electric-powered flight is a reality in the next decade and that there is adoption from the public to view this as a viable, natural form of transportation,” she says.
Post Syndicated from David Schneider original https://spectrum.ieee.org/automaton/aerospace/aviation/dji-promises-to-add-airsense-to-its-new-drones
The company plans to include ADS-B receivers in next year’s drones weighing more than 250 grams
There’s been a lot of talk over the years about endowing drones with the ability to “sense and avoid” nearby aircraft—adding radar or optical sensors that would mimic what a pilot does when she peers out the window in all directions to be sure there are no other aircraft nearby on a collision course. But incorporating such sense-and-avoid capability is quite challenging technically, and would probably never be possible to add to small consumer drones.
Thankfully, the threat of mid-air collision can be reduced using a strategy that is much easier to implement: Have aircraft track their positions with GPS and then broadcast that information to one another, so that everybody knows where everybody else is flying. Drones could at least receive those broadcasts and alert their operators or automatically adjust their flying to steer well clear of planes and helicopters.
Indeed, DJI, the world’s leading drone manufacturer, has already outfitted some if its drones with just this ability, and today it announced that by 2020 it would include that feature, which it calls “AirSense,” in all new drones it releases that weigh more than 250 grams.
Air Race E organizer looks to field inaugural race by late 2020
Although racing airplanes for sport has been a popular pastime around the world since the 1930s, its essential technology hasn’t changed much. Although computer design and engineering have greatly enhanced race planes’ thrust, economy, and maneuverability, the air racers still rely on petroleum-fueled propeller engines the way they did decades ago.
One entrepreneur is looking to fundamentally change the equation as soon as next year. He’s attempting to make air racing leapfrog past hybrid EVs and biofuels and go straight to all-electric propulsion.
“So, what we’re doing is taking the Formula One Air Racing rules,” says Jeff Zaltman, CEO of Dubai-headquartered Air Race Events, “and just changing the parts relevant to the propulsion system [so they run on electricity].” Zaltman adds that “We’re trying to change as little as possible as a starting point so the sport can transfer and migrate very easily.”
Air Race Events is currently scouting out a location to host the first ever event for Air Race E, the moniker given to the new, all-electric air racing division. (Expect an announcement, Zaltman says, by the end of the year or the beginning of 2020.)
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