Turbine car

[Jens]

Here are a couple of articles (book reviews) of Chryslers attempts to put a turbine into a car. It seems like there were only up-sides to the turbine powered cars including considerably longer life to a turbine compared to a piston engine as well as being able to run on anything flammable.

There are a few small turbine engines around. I have no idea of costs or life expectancy as these engines are used to power airplane models. I have not dug any further on this but I think it is a very interesting subject and should merit some discussion.

A picture to ponder - an engine the size of 5 gallon bucket including a gear train to bring the speed down, directly coupled to a generator head, the exhaust running through a heat exchanger to recover the large amount of heat that comes out of the exhaust.
Running at 60000 rpm or more, there is no issue with flickering, engine speed would probably be rock steady, no vibration etc etc etc ....

http://online.wsj.com/article/SB10001424052748703369704575462133272933798.html

http://jalopnik.com/5662006/the-rise-and-fall-of-americas-jet+powered-car

[AdeV]

Bah, us Brits were messing around with jet cars back in the '50s (as a race, we are completely nuts, you do realise that?):

http://www.rover.org.nz/pages/jet/jet5.htm

Better yet, Jaguar have just come out with a new one:

http://www.telegraph.co.uk/motoring/motor-shows/paris-motor-show/8033781/Paris-Motor-Show-2010-Jaguar-creates-electric-supercar-with-jet-engine.html

Like I said... bonkers 

[Henry W]

I probably saw that car at the 1964 New York Worlds Fair. I don't remember it though. My dad was a motor head and knowing him we saw it. At age six I was more into eating the super salty pop corn and drinking over syruped fountain drinks there and getting sick after. Than I got seperated from my parents and got lost. I remember sitting under Dino the dinosaur full of tears. My dad found me a while later, boy what a sight seeing him. He did not even beat my behind. I guess in a croud of millions of people he was just glad to find me. Boy that was the last time in my life I got seperated from my parents.

To bad I don't remember that car.

Henry

[mobile_bob]

check out "capstone"

they have a turbine powered cogen that has been around for some time now

then check out nasa's brayton cycle alternator, turns 50krpm iirc
highly efficient and 7plus kwe from an alternator that is scarcely larger than a softball

bob g

[Henry W]

I think it will be more than one would expect to just replace bearings. Back in 1985 I worked in a ballancing shop for a company that used GE, Alison, Prat and Whitney and Mitsubishi Turbines for run Generator, pumps and compressors for the oil and gas companies. Any accessive vibration will tear any of these turbines up.It took at times over a week to get just one complete assembly ballanced to run reliably. And you cannot put the juice to it on first startup.
On test runs we would have electric pumps pumping oil to all the bearings. and fuel circulating through the fuel pumps to keep them lubricated. We used a large air motor to spin them up for testing. The compressor engine was a Detroit V12 and that alone was enough to drive you nuts having that running in the building next door. IT WAS LOUD. It was a crew of four in the ballancing shop alone and we had to double check each others work. Yes together we blew up a few turbines and they were very costly indeed.

The only turbine that I see would be cost effective for our application is if they can make cheap reliable non-rebuildable (disposable) turbines. Turbines have a very Long life so replacement should not be often. The other issue is a reliable drive train that can take such sustained hi rpm's.


Henry

[Henry W]

Bob, Jens,

That is some pretty intresting stuff.

http://www.capstoneturbine.com/prodsol/products/

They are tiny compaired to what I used to work on.

I have to read up on more of this.

Henry

[Ronmar]

Turbine in car = poor fuel economy for the work performed.  I havn't read any specs on a turbine hybrid, and a really small turbine could be utilized in this application, so it might be reasonable especially with weight being a key efficiency factor in a hybrid.  This however would be offset by the need for a larger electric motor.  The turbine HP would be more difficult to put directly to the wheels in a higher speed/cruise application like the Prius does, so the electric would have to run 100% of the time.  

The largest failing is the BSFC of the turbine.  The high HP to weight ratio makes this somewhat offset for aircraft where weight hauled aloft = fuel burnt.  Less weight in engine means more weight in cargo.  You can also put a really big punch in a small package.  The turbines I operated on my last ship cranked out 25,000 SHP each, and were, enclosure included, a little smaller than the 16 cylinder 3,000 SHP diesel engines we used in tandem on each shaft for standard ops.  Their reduction gear however each would fill a fairly large living room, and were oh my god heavy...  I think the key to use them in a hybrid or cogen application is to do so without a reduction gear using a specially designed direct drive high speed generator.  I believe this is what the M1 Abrams tank uses in it's current APU.  In this case though, the APU provides electricity and heat like a COGEN, and it provides pressurized air to run thru special filters to provide cabin air for the crew to breath in hostile environments (nuculear/biological).     In a cogen application, because they have such a large air thruput, you will need a unusually large heat exchanger to have enough time to get a useable ammount of heat back from the exhaust. The benefit though is simplicity.  Since they are internally air cooled, all the heat is in the exhaust.      

[Henry W]

Ronmar,

I remember the reduction units to drive the MW genheads. They were huge! I would hate to see what they cost.

But these Micro turbine units are pretty intresting. I guess time will tell. They have to get the cost way down for the middle class consumer to purchase one.

Henry

[jimmason]

we have one of the capstone 30kw microturbines in our shop in berkeley.  we picked it up used after the dotcom crash, from a facility using it for back up power.

the capstone is a very impressive piece of engineering.  however, the prices on them are well above comparable piston based solutions, with only minor efficiency gains.  the air bearing is claimed to have very long life. 

like all power equipment, the total value has to work out.  it does not with the capstone.  nonetheless, it is very fun to play with.  if you are in the area, you are welcome to come by and see it spin up.

jim

[BioHazard]

I remember seeing a FORD turbine engine on ebay a while ago, apparently they were experimenting using them with medium duty trucks I think. I guess that didn't work out...

A local paper mill put in a pair of 80MW turbines for cogeneration a few years ago, apparently it must work well for them since they spent something like $160 million on the whole project.  I can hear 'em humming all night at my shop 1/2 mile away.

[Ronmar]

An old friend of the family was an air force photographer and spent a lot of time in the southwest photographing various flight testing projects at edwards airfoce base in the 50's-60's.  He told me about a few of the specialized vehicles they used to test and move some of the experimental aircraft.  They used several turbine powered flat bed trucks to move stuff between the various desert sites.  They were loud, guzzled fuel(MPG measured as GPM) and at full tilt left a trail like a F-4 flying low across the desert.

Foil-air bearings, Now there is a cool technology that removes the need for a pressurized lubrication system.  At rated RPM, there is no physical contact between shaft and bearing surfaces.  Very low drag...

[mike90045]

Wouldn't  a turbine be fine for a fixed installation ? (capstone) but grenade itself in a vehicle, when you hit a pothole, as the vehicle moves, and the shaft with blades ( gyroscope ) doesn't ?

[AdeV]

Wouldn't  a turbine be fine for a fixed installation ? (capstone) but grenade itself in a vehicle, when you hit a pothole, as the vehicle moves, and the shaft with blades ( gyroscope ) doesn't ?

I can't see it being any worse than some of the nastier turbulence that regular commercial jets encounter; and military jets seem to be able to take vast abuses & survive...

I think the gyroscope effect wouldn't cause any problems with a vertical motion (bounce), but it might resist turning left/right...

[vdubnut62]

Wouldn't  a turbine be fine for a fixed installation ? (capstone) but grenade itself in a vehicle, when you hit a pothole, as the vehicle moves, and the shaft with blades ( gyroscope ) doesn't ?

I can't see it being any worse than some of the nastier turbulence that regular commercial jets encounter; and military jets seem to be able to take vast abuses & survive...

I think the gyroscope effect wouldn't cause any problems with a vertical motion (bounce), but it might resist turning left/right...

Yes and turbine helos don't seem to have a problem.
Ron

[Ronmar]

It adds stress to the bearings as the case moves and in turn moves the rotor, but the bearings are designed to withstand and transfer this stress, just like the rod bearing in an engine is designed to transfer the stress of the piston accelerating and decelerating and the forces of compression and combustion without self destructing...  The ship I was on was an icebreaker.  There is not too much more violent an application for a turbine that I am aware of.  Imagine driving down the worst washboarded road you have ever been on.  I mean shake the fillings out of your teeth rough.  That is about the best way I can describe icebreaking.  If our FT-4's could survive that 24/7 for weeks at a time,  anything else would be a cake walk IMO.