It may seem small in comparison, but it's 150lbs less you have to pay fuel for, for the entire service life of the plane. While this probably wouldn't be a huge chunk of profits gone, why waste money? After a while the fuel needed to ship that extra 150lbs certainly adds up. I wouldn't want to pay for it!
Exactly. On long haul flights (which is the 787's mission) weight is critical due to the increase in fuel burn over the trip. More weight means more lift, more lift means more drag, and more drag means higher fuel flow.
For example, on a typical 8 to 9 hour trans-Atlantic flight, if you choose to carry another 1000 lbs of fuel at takeoff, you'll have roughly 600 - 700 lbs more on arrival - the other 300 - 400 lbs were spent to carry the weight of the extra fuel. (The actual penalty will vary by aircraft.) So, shaving 150 lbs off the plane can save you roughly 40 - 50 lbs per flight, twice a day, year after year. That's over 5000 gallons of $1.89/gallon jet fuel per year.
...Assistant Secretary Karsner said... "We are eager to see this accomplishment translate into the marketplace as soon as possible, which has the potential to help reduce our nation's reliance on imported oil and increase our energy security."
If the DOE Assistant Secretary thinks that electricity production has any meaningful impact on oil imports, the DOE is in trouble.
With the possible exception of AK and HI, not much oil is burned for electricity generation in the US.
This advance could be good on many levels, but oil imports isn't one of them.
This is a gas turbine: flow of gas turns the rotor.
Correct.
The similar thing that is used in dams to generate electricity. It is not a machine that burns the gas so it is has nothing to do with carnot cycle.
This is a fuel burner - there may be some confusion as to where they're claiming 95% efficiency.
A dam converts potential energy into electricity without combustion, hence it's high efficiency. The article is about a machine that burns fuel - that's where the flow of gas that turns the turbine comes from.
Turbine engine engine efficiency is most definitely connected to compression and combustion temps. That's *one* of the main reasons todays jet ( i.e., turbine) engines are so much more efficient than older engines - better turbine materials can withstand higher temps.
If they're claiming 95% efficiency, they must be referring to only the power out of the turbine versus the power into the turbine section. I don't remember any of the formulas for turbine engine efficiency, but the entire cycle efficiency is absolutely a function of compression and combustion temp. One of the big balancing acts in jet engine design is upping the compression ratio without having the high pressure escape out the front of the engine, which is a 'compressor stall' - a jet engine version of a backfire.
I've since opened an account with TD Waterhouse (aka Ameritrade) and make most of my trades through them, in part because of etrade's callous treatment of my privacy. I wonder how many others have done the same...
That's ironic, because the email account I used for Ameritrade only became the target of pump and dump spam.
To give them some of the benefit of doubt, it was ameritrade@somedomain.com. I wouldn't be surprised if the pump and dumpers use similar addressesfor all the domains they spam.
There is no way other than the use of industrial espionage to explain the short amount of time China took in developing its space program and supercomputer capabilities.
One of the most incredible stories of ex-military hardware making it into civilain hands was Darryl Greenamyer's F-104, built from parts scrounged all over.
An ex-Lockheed test pilot, his goal was to set an absolute altitude record with it - zoom climb it to flame-out, and control the ballistic portion of the flight with reaction thrusters.
After setting a low altitude speed record with it, but before the altitude attempt, Greenamyer had to punch out when one landing gear failed to extend. (You'd never survivve a gear up landing in an F-104.)
I'd hoped to find a lot more info on it on google, but will have to settle for this: Greenamyer
Slashdot Mirror
It may seem small in comparison, but it's 150lbs less you have to pay fuel for, for the entire service life of the plane. While this probably wouldn't be a huge chunk of profits gone, why waste money? After a while the fuel needed to ship that extra 150lbs certainly adds up. I wouldn't want to pay for it!
Exactly. On long haul flights (which is the 787's mission) weight is critical due to the increase in fuel burn over the trip. More weight means more lift, more lift means more drag, and more drag means higher fuel flow.
For example, on a typical 8 to 9 hour trans-Atlantic flight, if you choose to carry another 1000 lbs of fuel at takeoff, you'll have roughly 600 - 700 lbs more on arrival - the other 300 - 400 lbs were spent to carry the weight of the extra fuel. (The actual penalty will vary by aircraft.) So, shaving 150 lbs off the plane can save you roughly 40 - 50 lbs per flight, twice a day, year after year. That's over 5000 gallons of $1.89/gallon jet fuel per year.
And no, skinny crewmembers don't get a bonus.
If the DOE Assistant Secretary thinks that electricity production has any meaningful impact on oil imports, the DOE is in trouble.
With the possible exception of AK and HI, not much oil is burned for electricity generation in the US.
This advance could be good on many levels, but oil imports isn't one of them.
For very small values of 'for sure.'
That's interesting - I've never seen it pointed out that a dam can be looked at as a Carnot cycle.
I guess engineers see efficiency in terms of the part of the cycle they control or have to pay for the input for.
This is a gas turbine: flow of gas turns the rotor.
Correct.
The similar thing that is used in dams to generate electricity. It is not a machine that burns the gas so it is has nothing to do with carnot cycle.
This is a fuel burner - there may be some confusion as to where they're claiming 95% efficiency.
A dam converts potential energy into electricity without combustion, hence it's high efficiency. The article is about a machine that burns fuel - that's where the flow of gas that turns the turbine comes from.
Turbine engine engine efficiency is most definitely connected to compression and combustion temps. That's *one* of the main reasons todays jet ( i.e., turbine) engines are so much more efficient than older engines - better turbine materials can withstand higher temps.
If they're claiming 95% efficiency, they must be referring to only the power out of the turbine versus the power into the turbine section. I don't remember any of the formulas for turbine engine efficiency, but the entire cycle efficiency is absolutely a function of compression and combustion temp. One of the big balancing acts in jet engine design is upping the compression ratio without having the high pressure escape out the front of the engine, which is a 'compressor stall' - a jet engine version of a backfire.
Yet more proof that the moon landings were a hoax.
There's someone you really ought to meet.
I've since opened an account with TD Waterhouse (aka Ameritrade) and make most of my trades through them, in part because of etrade's callous treatment of my privacy. I wonder how many others have done the same...
That's ironic, because the email account I used for Ameritrade only became the target of pump and dump spam.
To give them some of the benefit of doubt, it was ameritrade@somedomain.com. I wouldn't be surprised if the pump and dumpers use similar addressesfor all the domains they spam.
It's called trust. Remember that?
Trust, but verify.
Ron
I see it coming already: "I fart in your general direction. Your mother was a hamster and your father smelt of elderberries."
Reaches for remote...
"Now go away or I shall taunt you a second time."
I'm not so sure this is a good idea.
Now there's a slashdot 'speler' for you...
The insurgency is in it's last throes.
Did they use refractors vs. an off the shelf 8" or 10" SCT for higher contrast?
It would be nice to know more about the design and trade-offs of the entire camera.
All your base pair are belong to us.
Die-By-Wireless
or to explain how Linux overtook SCO. ;-)
Let's see, 400 seconds - 28.6 seconds .... works out to about 50 years. Still.
If your solar power is driving a propeller, M1.1 is most definitely not achievable.
An ex-Lockheed test pilot, his goal was to set an absolute altitude record with it - zoom climb it to flame-out, and control the ballistic portion of the flight with reaction thrusters.
After setting a low altitude speed record with it, but before the altitude attempt, Greenamyer had to punch out when one landing gear failed to extend. (You'd never survivve a gear up landing in an F-104.)
I'd hoped to find a lot more info on it on google, but will have to settle for this: Greenamyer
Hmmm.
I think that still need some work.
He'll be squealing for his new associates.
Mark S.
The flywheels were made out of composites, spun at incredible speeds, were housed in a vacuum and supported by magnetic bearings.
The auto makers didn't pick up on it, but they said stationary power storage was another possible market.
I can references to US Flywheel Systems on google, but no site for it. Curious as to what happened to them.
Battery maintenance is a PITA. Sure would be nice to see something like this work out.
Considering France's economy, maybe they're talking about this cashless economy. (Scroll down for 'Area Man Participates in Cashless Economy.')
I think back to the 80's when I got my first hard drive period. $700 for a 20MB 'MacBottom' for my Mac Plus.
I also had hair then, and ... oh, well. Never mind.
Editors - how about feeding us some articles with some real info in them? There just might be some technical people in this crowd who'd read them.