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solarsculptor
User Rank
Silver
Legacy thinking still evident
solarsculptor   2/7/2013 11:07:23 AM
The auto companies are still stuck in their old way of thinking. The primary sales tactic that they have used to sell their cars is by defining "improved" as having more HP and faster acceleration. Granted the Corvette is a specialty car, being sold based on performance. However maybe chopping some of the fat off of it's 3200 lb frame with some advanced materials might not require 440 hp to move a bit quicker...

Only about 12% of the energy burned by a "modern" car translates into motion, that why they have such gigantic cooling systems. Hopefully the companies will use their time and money wisely and not just try to "run out the clock" before the 54mpg standard kickes in.

One point made about driving habits improving mileage is well taken. However human nature is hard to change (I can't get my wife to lighten up her lead foot for example as long as I'm paying for the gas and repairs) but the self drive car could very well change that especially if it includes networked roadways whereby the cars communicate with each other, maybe even "drafting" safely to save fuel.

williamlweaver
User Rank
Platinum
Re: Diesel Electric Locomotives
williamlweaver   2/7/2013 10:54:01 AM
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Thanks for that Jim_E! Wow... I love learning new stuff. I had no idea that GE made traditional reciprocating engines. Shows how biased I am from working with the Air Force... the only piston engines from GE I saw were housed in the Air Force Museum.

Perhaps I confused GE with General Dyamics (GD)... Their M1 Abrams Tank uses a gas turbine engine and I mistakenly thought they had borrowed that technology from Locomotives (it's a heavy, freaking tank after all). A quick visit to ge.com reveals that their modern locomotives use a 12-cylender diesel engine. Thanks for the reality check!

Looks like the Gas Turbine-Electric Locomotives peaked in the 1960s. I guess I'm only missing 50 years of technology...  =] 

http://en.wikipedia.org/wiki/Gas_turbine-electric_locomotive

GTOlover
User Rank
Platinum
Re: Diesel Electric Locomotives
GTOlover   2/7/2013 10:45:39 AM
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I am a huge model railroad fan and love to photograph those big diesels to get good realistic weathering. Thanks for the input. I did not know that about the engines.

Do you know what the comparitive conversion of the fuel to locomotion is? For example, loco pulling 30000 lbs gets 3 MPG (or 3 gallons per mile GPM).

Jim_E
User Rank
Platinum
Diesel Electric Locomotives
Jim_E   2/7/2013 10:21:22 AM
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Being a huge railfan, I have to tell you that modern diesel electric locomotives do not have turbines.  They feature traditional piston driven diesel engines connected to an alternator.  I believe the the General Electric locomotives feature four stroke diesel engines, while the Electro-Motive Diesels (a.k.a EMD) (formerly owned by General Motors) feature two stroke diesel engines.  Both manufactures utilize turbo charging.

I sure like the sound of the EMDs better than that of the GE's.

It was interesting that there was a horsepower race by the locomotive builders about ten years ago, and it ended with both companies making 6000 horsepower locomotives.  Ironically, they both seemed to have problems and lost favor with the railroads.  They both now produce their largest units with about 4500 horsepower, which seems to be the sweet spot.  Since additional locomotives can be attached together to be operated by lead locomotive (MU'd meaning Multiple Units), more locomotives can be added when they need extra power.

 

williamlweaver
User Rank
Platinum
Re: New technology, but where are the MPGs?
williamlweaver   2/7/2013 10:02:33 AM
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GTOlover, this is one of my favorite Wikipedia Pages http://en.wikipedia.org/wiki/Energy_density. I agree with you in separating the variables. One is the variable of how much Total Energy can you carry on board in the form of fuel  while you are traveling and a second variable is how efficiently can the energy in the fuel be Converted into kinetic energy of the vehicle. I think the automobile industry is currently suffering from the "Opportunity Costs of Legacies". We've been doing the same thing for such a long time that it is proven technology, accepted by the regulators, entrenched in our supply chains, and there is a huge activation cost for thinking outside the 20th-century box. We don't keep an account of Opportunity Cost, but I would anticipate that the cost savings we are missing out on by drowning in our current technological inertia would far outstrip the actual costs of not innovating...

GTOlover
User Rank
Platinum
New technology, but where are the MPGs?
GTOlover   2/7/2013 9:23:01 AM
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Looking at some of the MPG ratings that are stated in the slideshow, and checking some online, where is the fuel economy? I have a 1990 GMC Suburban 5.7L that I can get upto 20 MPG by just using good driving habits to maximize mileage. I have a 1968 Tempest with a 5.7L that I have been able to get 21 MPG with good driving habits. I realize that these would get even better mileage by using the same driving habits. But the cost of this research and development is improving thesevehicle MPG by about 5 - 7 MPG. That is 20%, not bad, but still a long way off from 51.4 MPG!

I got to thinking, what is the energy content in one gallon of gasoline and how much work can it generate to move a 4000 pound vehicle? The process of electrification is only covering up the conversion problem. As William pointed out, how about optimizing the conversion by using turbine poweres generators. Seems this is a idea that needs some more thought.

williamlweaver
User Rank
Platinum
Re: Doing what they do best
williamlweaver   2/6/2013 10:06:08 PM
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Thanks for that tekochip. That's why I'm wondering why we don't use turbine technology to charge / recharge the batteries of a modern hybrid. Not being an engineer, I find statements like "the relatively constant torque of an electric motor, even at very low speeds tends to increase acceleration performance of an electric vehicle relative to that of the same rated motor power internal combustion engine" (Wikipedia) promising. Instead of developing new transmission technology to mechanically couple the output of the turbine to the differential, it seems an obvious mashup to use an efficient turbine to generate electricity for a modern electric car.

And Chuck, all the more efficient if we use diesel. I've read of several "gas" turbines that accept methane, gasoline, kerosene, diesel, and Jet A. Now I just need to develop one... 

Ack!

While surfing I found a fairly recent article on Discovery.com - http://news.discovery.com/autos/drive/beyond-piston-engines-gas-turbine-cars.htm

"The Jaguar C-X75, the concept that debuted at the 2010 Paris Motor Show, is an electric hybrid that uses two small gas-powered turbines to generate electricity when the battery is low.  Looking at the stats, it's an impressive ride: an estimated fuel economy of 41.1 mpg, 778 horsepower,  0 to 62mph in 3.4 seconds, and a top speed of 205 mph."

Charles Murray
User Rank
Blogger
Re: Doing what they do best
Charles Murray   2/6/2013 9:38:35 PM
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Personally, Bill, I'd be happy just to see the U.S. car industry make more use of diesel technology. Diesel fuel has about 10% more energy per volume than conventional gasoline. The problem, though, is that diesel engine technology is more expensive. One industry engineer told me that the base diesel engine is about 2X as expensive to make as a regular gasoline engine.   

Charles Murray
User Rank
Blogger
Re: Doing what they do best
Charles Murray   2/6/2013 9:29:27 PM
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The most famous turbine engine, of course, was the one in Parnelli Jones' car at Indy in 1967. The car left the race with three laps to go when a transmission bearing broke. I believe turbine engines were barred from Indy races afterward.

tekochip
User Rank
Platinum
Re: Doing what they do best
tekochip   2/6/2013 2:24:28 PM
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I believe Chrysler had a turbine car in the early Sixties.  It had a number of new technology problems, but I think the biggest issue was that a turbine engine needs to spool up, so acceleration was rather poor.  If only they made merge lanes as long as runways.

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