Aviation experts said the energetic quality of lithium-ion can be a concern onboard aircraft. "One of the issues with lithium batteries is they get very hot," Freiwald said. "When they ignite, they can burn so hot that Halon 1301 won't extinguish a fire."
Automakers, many of whom use lithium-ion chemistries in hybrids and electric cars, typically operate their batteries with cooling systems. The Chevy Volt, for example, employs a fluid coolant that circulates through 1mm thick channels machined into 144 metal plates sitting between the battery's cells. Other automakers have employed air cooling on hybrids.
Even with cooling, however, lithium-ion automotive batteries have been known to have problems on rare occasions. In 2011, a fire started in a Chevy Volt weeks after government crash testing, causing a ripple of concern. "The chemistry is edgy," Donald Sadoway of MIT wrote in an email to Design News after the incident. "The electrolyte is an organic fluid that is flammable, highly volatile at even moderately elevated temperature and in the presence of metallic lithium, which can form on the negative electrode at high charging rates."
Although it's not known whether the Dreamliner employs battery cooling systems, its batteries are smaller than those of plug-in hybrid cars. A National Transportation Board (NTSB) examination of an auxiliary power battery unit from the JAL Boeing 787 that caught fire in Boston's Logan Airport on January 7 showed that it measures 19 inches x 13 inches x 10 inches and weighs just 63 pounds. In contrast, electric vehicle batteries can weigh more than 400 pounds.
Freiwald said he doubts the two reported fuel leaks are related to the overheating incidents. Those were more likely to have been caused by human error, he said.
Experts who spoke with Design News emphasized that the cause of the problems isn't fully understood yet, and that such incidents need to be put into perspective. "None of these were catastrophic failures," Dietz told us. "The engineering systems provided an alert to the failures and action was taken. There should be some solace in that."
Seems like the batteries are the culprit, but as of now no one knows why. They've x-rayed the batteries, put them through CT scans, disassembled them and checked the associated wiring bundles and battery management circuit boards. As of now, regulators have said that overcharging doesn't seem to be the issue, but we don't know much more than that. We'll have more coverage on this coming up.
max take off weight of 787-9 is 251 metric tons (modification for long distanses 15700km), total force from engines 64.4tons
amazingly 787-3 (not in production) has near 170 tons weight and flight distance 5500km, total engine force 48 tons - look like very different plain, but with same design & engines.
By refining topologies and using new fluid technology, Moog's new peak sine drive controller increases available power without increasing controller volume.
Lantronix Inc. has expanded its line of controllers for sensor networks with the release of a rugged controller that improves management of automation systems used in a number of industries, including manufacturing, oil and gas, and chemicals.
Inspired by the hooks a parasitic worm uses to penetrate its host's intestines, the Karp Lab has invented a flexible adhesive patch covered with microneedles that adheres well to wet, soft tissues, but doesn't cause damage when removed.
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A quick look into the merger of two powerhouse 3D printing OEMs and the new leader in rapid prototyping solutions, Stratasys. The industrial revolution is now led by 3D printing and engineers are given the opportunity to fully maximize their design capabilities, reduce their time-to-market and functionally test prototypes cheaper, faster and easier. Bruce Bradshaw, Director of Marketing in North America, will explore the large product offering and variety of materials that will help CAD designers articulate their product design with actual, physical prototypes. This broadcast will dive deep into technical information including application specific stories from real world customers and their experiences with 3D printing. 3D Printing is
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