Gas turbine/electric hybrid?

"Electric motors develop maximum torque at zero rpm......."

Is that so? Unfortunately Nomen, you are a poser, just cutting and pasting things you read. That leaves you making error after error in how things are or could be.

Depends on the type of motor used.

Actually turbine-electric makes some sense: turbines are efficient at constant speed and offer both high efficiency and light weight, offsetting the heavy batteries. Regeneration is unnecessary in a constant--power setup: the turbine expanders can be optimized for that regime.

Emissions would be a deal killer because it would take intense and long development to get them to recip standards. The best thing that could be done for turbine car buffs would be to enact a emissions _certificatiion_ waiver for turbine cars for a set time, so as to make it worthwhile for some company to build a fair run of them. The waiver should be carefully written to force the outright sale, not lease or test loan, of the cars so they cannot destroy them like the Chrysler TC program or the GM and Ford factory electrics.

If you want to look at economical hybrids, look to a diesel-electric combination like locomotives use. In a vehicle hybrid of this sort the electric motors would always be the prime movers and the diesel would use an auto-throttle and auto-switch to either send the electricty directly to the motors or into storage batteries. You accelerator pedal would regulate the juice going to the electric motors only and not the RPM of the charging diesel. Since diesels are more efficient at idle than a gasoline motor of the same size/output, you can use the power in the batteries to do all the accelerating and stop-and-go driving (keeping the diesel at idle RPM for a much longer time than using a directly coupled motor) and only have the diesel increase RPM when you need either the batteries charged or a direct flow to the electric motors for power. In addition, a hybrid of this type would not need any significant leaps of technology or waivers for emissions.

Just my two cents worth - Jonathan

Gas turbine engines are very expensive to build. I doubt that we will ever see significant application to automobiles. It has been tried, many times, and came up short.

John

It would make _more_ economic sense, but it still wouldn't make economic sense, not at US fuel prices. A few people would pay a lot of money for the novelty of a turbine car, diesels are not novel. Straight diesel cars, which do make economic sense, are unobtanium in the US, because of consumer apathy and emissions laws combined with a refusal to require Euro-spec fuel for the current generatioon of CRD engines.

Well Mr. Bundy, I am afraid that Nomen is correct, at least for permanent magnet electric motors. Have a look at:

And the V12 in the Lambo is a low build cost powerplant?? No, gas turbines are not necessarily incredibly expensive to build. My guess is the Allison 250 costs less to build than a Lyc or Continental recip of half the power: the P&W PT-6 is probably twenty or thirty thousand dollars of actual labor, materials, and other hard build cost.

There are probably five hundred people who would buy a turbine exotic car in the $200-300K price class in the US any given year, enough to make it doable. The "Bugatti" Veyron is well into seven figures, at which point buying a off the shelf ST6 at market price from P&WC becomes a legit option economically speaking. However, it would make for a miserable road car, but the Veyron probably is that to begin with, to say nothing of the modified Stingray the Granatellis foisted off on some dumb yuppie idiot for a six-figure price with a junk runout training PT6 they mooched off P&W a decade earlier many years ago.

Well John, you are wrong because you took a blanket statement and qualified it to suit your answer. Again, nice pasting job though.

There are a LOT of varibles in electric motor design that can effect at what RPM peak effort is achieved. Generally though with traction type motors used to power electric cars and such, they achive maximum torque at zero or very low RPMs to get the load moving.

Yeah.... like all that technology developed under NASA/ Space funding.. total waste of money, considering we never saw any of it!

Good Catch!

NASA developed many new technologies that have passed on to the public.

Do a Google search, you will be impressed.

Progress is never a waste of money.

What about velcro ? High impact plastic ? Fuel Cells ? GPS ? Satellite TV and Radio ?

Lynn

Heh.. gee... never THOUGHT of that!!1

;)

There's more, btw.

Actually the DOD was behind the GPS program at the start. NASA provided the taxi for it.

More importantly what about the need to make things small that let to better computers, cell phones, and microscopic surgery such as eye surgery, organ surgery and transplants. As well as the ability to reattach severed limbs etc?

mike hunt

Most of the things you mention had a tangential relationship to the space program. It's true the space program speeded up many of those things, but not that we would not have any of it without them. And perhaps the pace of progress would have limited some of the regress we have to face too, like offshoring of jobs, elimination of repair jobs, and cheapening of all manner of products. It goes both ways.

Once a company has derived most of its income from NASA or the Air Force it is permanently spoiled and will never want to work again for a living. You'd have to fire or kill all of the executives and most of the management to get them to pursue gainful market endeavors at reasonable per-piece profit levels.

The Space Program's necessity of the materials, mapping, weather forcasting, etc. promted their development and the speed of their developement. The things mentioned may not be here today if it had not been for the Space Program. True, your point of jobs, it does go both ways, but , a basic economics class dictates if one has the money and needs labor, and one has a labor pool, but needs the money, a relationship will develope that will benefit both. Nothing new, been going on for thousands of years.

As long as the contractor is delivering their products within the contractual requirements of NASA and the Air Force, they are within a gainfull market.

And, tell that to Boeing... in this case, both Bret's and Franks' points are made

Copy and paste both lines.

Carbon fiber technology developed for steath bomber, used in commercial aircraft. The issue: military secret or not?

Whatever the case, not only is the market global, but also the product and manufacturing source.

No... it isnt as easy as just keeping it to ourselves... in the competitive market, it goes both ways. The alternative is that, if you DO attempt to keep such close to the vest, some politico just deals it away without thinking, in return for campaign contributions. See: Clinton Campaign/China - Missile guidance systems scandal.

Well now you are talking about a whole different animal, a high-priced vehicle for those with more money than sense. All in all not an interesting topic of speculation. I would agree that the only way a turbine has a fighting chance in automotive use would be as a fuel burner to power a generator for a true hybrid powertrain where there is no mechanical connection between the fuel burning engine and the drive wheels. Trains have been built with such a powertrain for decades, and AFAIK, none use a turbine engine. GE locomotives has made a bunch of these trains and GE is also a top builder of turbine/jet engines, so I bet they have looked at it in depth.

John