If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#21
|
|||
|
|||
How Beat The High Cost Of Fuel: The ElectraFlyer-C
On Mon, 23 Jun 2008 09:29:03 GMT, Frank Olson
wrote in z1K7k.22157$kx.14483@pd7urf3no: I'm waiting for the twin version. :-) It looks as though development is planned to continue: http://www.avweb.com/eletter/archive...ll.html#198151 Fishman has about six flights on his ElectraFlyer-C. With real-world experience behind him, plus calculations in front of him, Fishman believes he may have in this aircraft a single-place experimental that can fly at about 70 mph for up to one hour on batteries alone -- provided the pilot chooses to land with a half hour's power in reserve. Maximum endurance under power (calculated, and to be proven by further flight testing) is expected to be near 90 minutes. Fuel cost for that flight? Less than 75 cents. The aircraft is scheduled to be front and center at AirVenture Oshkosh this year, but Fishman told AVweb last week that his eyes are on a bigger prize -- a larger, more powerful, electric LSA. Fishman's goals include plans to offer a 40-hp electric motor, plus a controller and battery solution for use in highly efficient light sport aircraft ... pending approval of and standards for electric motors in LSAs. He's currently seeking sponsors, and the manufacturer of a highly efficient, very lightweight airframe with which to partner. Until then, expect Fishman's ElectraFlyer-C to be on display this year at the epicenter of AirVenture Oshkosh -- AeroShell Square. .... As it is, Fishman's ElectraFlyer-C is the pairing of his 29-pound, 18-hp electric motor and regenerative-braking-capable controller package with two lithium polymer battery packs (that together weigh 78 pounds), adapted to an airframe that began life as a Moni motorglider. The Moni is a highly efficient all-aluminum (and discontinued) design with an 18:1 glide ratio and a 27.5-foot wingspan. Fishman says his highly modified version, registered as the ElectraFlyer-C, weighs in at just under 380 pounds with "full fuel," offers a confirmed 60-percent increase in thrust over the Moni, has made engine reliability a non-issue and practically eliminates vibration and engine noise. By AirVenture, Fishman believes the ElectraFlyer-C will have proven it can climb at better than 500 fpm, cruise at 70 mph, stall at 45, and fly under power for approximately 90 minutes (or 60 minutes if landing with the equivalent of a legal day VFR fuel reserve). A portable 110-volt charger can refill the tanks (as it were) in about six hours and more powerful chargers (220 volts) can do the job faster (two hours) where suitable outlets are available. NOTE: According to Fishman, following the first test flight, pilot Joe Bennis' first words were, "I want one." And after speaking with Fishman last week, it seems one person making the trip to Oshkosh this year just might have that option. See also http://www.flickr.com/photos/2722498...55156982/show/ |
#22
|
|||
|
|||
How Beat The High Cost Of Fuel: The ElectraFlyer-C
Stealth Pilot wrote:
this argument is like the one for valve sound systems vs digital systems. eventually digital won hands down after a few years of developing it. Apples and oranges. this is the start of a technology. if these guys can develop a weight competitive system that delivers just 100hp continuously for days at a time then they will have a huge market. potentially the entire world's private aviation market. of course they'll probably ignore that and just go for the commercial market. Except they can't as battery technology is an order of magnitude short on energy density to be able to do it. There is no battery technology in the foreseeable future that would allow one to build an electric airplane with the performance of a 152, much less a 172. That won't change until a new battery is invented. -- Jim Pennino Remove .spam.sux to reply. |
#23
|
|||
|
|||
How Beat The High Cost Of Fuel: The ElectraFlyer-C
|
#24
|
|||
|
|||
How Beat The High Cost Of Fuel: The ElectraFlyer-C
Larry Dighera wrote:
On Mon, 23 Jun 2008 15:15:03 GMT, wrote in : Except they can't as battery technology is an order of magnitude short on energy density to be able to do it. I've always thought that the energy stored in metallic aluminum might be harnessed for motive power. If you look at it on the energy density chart http://en.wikipedia.org/wiki/Energy_density, it would appear to be a reasonable energy source. Storage type Energy density Energy density by mass (MJ/kg) by volume (MJ/L) ---------------------------------------------------------- Gasoline[7] 46.9 34.6 Aluminum (burned in air) 31.0 83.8 Hydrazine (toxic) 19.5 19.3 combusted to N2+H2O So while aluminum isn't as rich an energy source pound-for-pound as gasoline, it is significantly better than rocket fuel. Well yeah, except it takes huge amounts of energy to make metallic aluminum from ore in the first place and burning aluminum is not something you really want to be around. -- Jim Pennino Remove .spam.sux to reply. |
#25
|
|||
|
|||
How Beat The High Cost Of Fuel: The ElectraFlyer-C
Larry Dighera wrote:
On Mon, 23 Jun 2008 15:15:03 GMT, wrote in : Except they can't as battery technology is an order of magnitude short on energy density to be able to do it. I've always thought that the energy stored in metallic aluminum might be harnessed for motive power. If you look at it on the energy density chart http://en.wikipedia.org/wiki/Energy_density, it would appear to be a reasonable energy source. Storage type Energy density Energy density by mass (MJ/kg) by volume (MJ/L) ---------------------------------------------------------- Gasoline[7] 46.9 34.6 Aluminum (burned in air) 31.0 83.8 Hydrazine (toxic) 19.5 19.3 combusted to N2+H2O So while aluminum isn't as rich an energy source pound-for-pound as gasoline, it is significantly better than rocket fuel. And what is the waste product for Aluminum burned in air? Really I don't have a clue. |
#26
|
|||
|
|||
How Beat The High Cost Of Fuel: The ElectraFlyer-C
Gig 601Xl Builder wrote:
And what is the waste product for Aluminum burned in air? Really I don't have a clue. Likely combustion equation: 4Al + 3O2 - 2Al2O3 The result on the right is Sapphire. |
#28
|
|||
|
|||
How Beat The High Cost Of Fuel: The ElectraFlyer-C
On Mon, 23 Jun 2008 14:40:39 -0500, Gig 601Xl Builder
wrote in : And what is the waste product for Aluminum burned in air? Really I don't have a clue. It's been way too long since I took chem to remember the reaction, but I'd speculate that it would be aluminum oxide. |
#29
|
|||
|
|||
How Beat The High Cost Of Fuel: The ElectraFlyer-C
"Scott" wrote in message ... Richard Riley wrote: On Jun 16, 7:37 pm, Larry Dighera wrote: How Beat The High Cost Of Fuel The motor is powered by a 78 pound, custom-built lithium-ion polymer battery with a power output of "5.6 kilowatt hours"; projected life is 300 to 500 full discharge cycles or more than 1,000 partial cycles. The battery can be recharged in as little as two hours using a 220-volt charger (or six hours with a 110-volt charger). The cost for a full recharge is 70 cents with the 110-volt charger. Fishman says it's feasible to carry a small 110-volt charger as baggage on cross-country flights. 1 horsepower = .75kw. So 5.6 kilowatt hours is only 7.51 horsepower hours. Good enough for a short burst to get you to altitude and soar the thermals, bu you aren't going anywhere cross country. Compare it to a really inefficient 2 stroke, burning .6 lb/hp-hr. Your battery is equal to .75 gallons of gas. Wait a second...5.6 KWH doesn't really tell you how much HP it is, does it? All it says is that it consumes 5.6KW in an hour. If you only ran the motor for 5 minutes per hours, the HP would be 12 times that or approx. 90 HP. Using KW HOURS doesn't tell the whole story. Running a 100W light bulb 10 hours uses 1 KWH and so does running a 500W bulb for 2 hours but the 500W bulb does more work at any instant in time (it's a lot brighter!). Now, if that motor was rated at 5.6KW, then yes, I'd agree it is about 7.5 HP. Scott You have a good point, but the KW Hours rating of the battery does seem a bit low. Even when you consider that cooling drag nearly absent, what little I think I know about the base airframe suggests that the battery rating needs to be at least twice the stated amount in order to provide the stated performance and endurance. The usual power of ten error in transcription does not make much sense in this case, but there are apparently two batteries of equal sive--and everything that I could find appeared to originate from a single article. In any case, it is interesting; but the economics really do not work based upon the stated maximum10 year and 1000 hour battery battery life. Even if the electricity was free and gasolene was more than twice its current cost, the gasolene powered airplane, on which it is bsed, would still give much greated utility for less cost. Nontheless, my hat's off to him for the effort. Peter |
#30
|
|||
|
|||
How Beat The High Cost Of Fuel: The ElectraFlyer-C
Larry Dighera wrote:
On Mon, 23 Jun 2008 16:35:03 GMT, wrote in : Larry Dighera wrote: On Mon, 23 Jun 2008 15:15:03 GMT, wrote in : Except they can't as battery technology is an order of magnitude short on energy density to be able to do it. I've always thought that the energy stored in metallic aluminum might be harnessed for motive power. If you look at it on the energy density chart http://en.wikipedia.org/wiki/Energy_density, it would appear to be a reasonable energy source. Storage type Energy density Energy density by mass (MJ/kg) by volume (MJ/L) ---------------------------------------------------------- Gasoline[7] 46.9 34.6 Aluminum (burned in air) 31.0 83.8 Hydrazine (toxic) 19.5 19.3 combusted to N2+H2O So while aluminum isn't as rich an energy source pound-for-pound as gasoline, it is significantly better than rocket fuel. Well yeah, except it takes huge amounts of energy to make metallic aluminum from ore in the first place Right. http://electrochem.cwru.edu/ed/encyc...a01-al-prod.ht It takes about 225 KWH to produce 50 lbs of metallic aluminum. That's just the final step in getting ore into metal. There is a lot of pre and post processing. All the energy that went into making the alumna into metallic aluminum is just waiting to power an IC engine. Grind the Al into a fine dust and blow it into the cylinders. :-) Aluminum dust bursts into flame all by itself, and rathe spectacularly when it does. I take you've not spent much time around a machine shop. and burning aluminum is not something you really want to be around. Can you tell me more about that? Aluminum burns at about 7000 degrees F and you don't really want to inhale aluminum oxide. -- Jim Pennino Remove .spam.sux to reply. |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Fighting the high cost of flying | Jay Honeck[_2_] | Piloting | 31 | June 11th 08 11:30 AM |
High Cost of Sportplanes | Gordon Arnaut | Home Built | 110 | November 18th 05 10:02 AM |
Fix the high cost [Was:] High Cost of Sportplanes | Evan Carew | Home Built | 40 | October 8th 05 04:05 AM |
These are not YOUR airplanes - Was: High Cost of Sportplanes | Lakeview Bill | Home Built | 28 | September 21st 05 01:37 PM |
Talk about the high cost of aviation! | C J Campbell | Piloting | 15 | August 12th 03 04:09 AM |