Design Con 2015
Breaking News
Design How-To

Aircraft structures take advantage of energy harvesting implementations

NO RATINGS
Page 1 / 6 Next >
More Related Links
View Comments: Newest First | Oldest First | Threaded View
David1975
User Rank
Rookie
re: Aircraft structures take advantage of energy harvesting implementations
David1975   12/15/2011 1:51:43 PM
NO RATINGS
Regarding the Aloha Airlines Flight 243 incident, in addition to the injuries, a flight attendeant was was blown out of the airplane and killed.

docdivakar
User Rank
CEO
re: Aircraft structures take advantage of energy harvesting implementations
docdivakar   7/8/2011 12:00:42 AM
NO RATINGS
Another useful article to read, related to the topic and discussion: Thermoelectric Energy Harvesting http://www.sensorsmag.com/networking-communications/energy-harvesting/thermoelectric-energy-harvesting-8708 With a 15degK temperature differential, it is possible to generate 1mW of power. MP Divakar

docdivakar
User Rank
CEO
re: Aircraft structures take advantage of energy harvesting implementations
docdivakar   7/7/2011 6:53:55 PM
NO RATINGS
Subsequent to my comment above, I ran into this article at IDTechEx's Energy Harvesting Journal: Energy harvesting sensors for aircraft http://www.energyharvestingjournal.com/articles/energy-harvesting-sensors-for-aircraft-00003545.asp?sessionid=1 One of the approaches discussed in the Energy Harvesting Journal is to tap into the temperature differentials between the outside (coooold!) and inside of the aircraft and use thermoelectric materials that can be used as heaters, coolers and generators. This article also leaves out details on how exactly the cracks are detected. Now a days, in addition to Aluminum / Titanium alloys, Carbon composites are used also in aircraft structures. The fracture mechanisms and the propagation of cracks are different in these materials and techniques suitable for one may not work for the others. Needless to say, there is a lot to be done here before 'systems' evolve where energy harvested (or powered) sensor nodes are used to provide real time data on the integrity of the aircraft while in operation or at rest. In short, an area of opportunity! Dr. MP Divakar

docdivakar
User Rank
CEO
re: Aircraft structures take advantage of energy harvesting implementations
docdivakar   6/19/2011 5:02:20 PM
NO RATINGS
This is article starts on a good premise but makes the case for acoustic emission techniques in fatigue crack propagation rather poorly. Also, there are many inaccurate statements. There are two major types of repetitive stressors in an aircraft's life: the high cycle fatigue (flutter in wings, aelerons and control structures are good examples) and low cycle fatigue (examples include de/pressurization of the cabin which expands & contracts the fuselage, landing gears...). The fatigue crack behavior is different for HCF & LCF, described in simple terms by the Paris equation. The optimal monitoring methodologies and tecniques for LCF & HCF effects assessment can be different and the article doesn't distinguish that at all. Secondly, the behavior of defects 'detected' by such sensor nets have to be strongly correlated between multiple states of the aircraft -while in flight, while on the ground, etc. The behavior of defects will be signicantly different in these states. The existence of defects in any assembly process is a given and the industry has found ways to keep their damaging effects to a minimum. @mysterylectricity: I see your point! Safety critical systems should never ever be trusted to a system without redundancy! I am for energy harvesting as a backup for structural integrity monitoring thru sensor nets, not as the primary source. Better yet, use energy harvesting for powering things like cabin lights, fans, even laptop chargers... Dr. MP Divakar

mysterylectricity
User Rank
Rookie
re: Aircraft structures take advantage of energy harvesting implementations
mysterylectricity   5/18/2011 12:58:58 PM
NO RATINGS
Very educational article, but seriously: is aircraft the proper testbed for this nascent technology? Whereas such self-powered sensors might seem reasonable during flight, can these systems be fully checked for operation before takeoff? Not without a blowtorch or some highly trained elephants in the hangar. Whereas loss of signal indicates a hard fault in most systems, such a fault in an energy-harvesting sensor leaves considerable ambiguity: is it the sensor proper, or is it simply a lack of harvestable power under the circumstances? I for one would not want to hear, "The pilot is waiting for the Sun to heat up the wings to the point where the sensors become active" while waiting for takeoff. C'mon. This must be a joke.

cdhmanning
User Rank
Rookie
re: Aircraft structures take advantage of energy harvesting implementations
cdhmanning   5/16/2011 6:34:21 PM
NO RATINGS
Don't forget turbulence! Has this actually been tested on aircraft or is it just theoretical? It seems almost pointless to do thermal harvesting around the engine since this area already has wiring. I can see some sense in doing it lesewhere though. It also seems challenging stepping up from low-bandwidth measurement of slow-changing signals like building stress measurement and tyre pressure measurement to monitoring an airframe. I would have expected that airframe measurements would require high frequency measurements to be analysed via FFT etc.

Flash Poll
Like Us on Facebook

Datasheets.com Parts Search

185 million searchable parts
(please enter a part number or hit search to begin)
EE Times on Twitter
EE Times Twitter Feed
Top Comments of the Week