Someones stealing PT Technology

[woodlandfarms]

I say this tongue in cheek, but this is a rather interesting concept...

100-MPG Hybrid Evokes The Classic '63 Corvette | Autopia from Wired.com

 

[woodlandfarms]

And sorry about my English, it appears you cannot edit titles..

 

[SnowRidge]

I say this tongue in cheek, but this is a rather interesting concept...

100-MPG Hybrid Evokes The Classic '63 Corvette | Autopia from Wired.com

Hydraulic accumulators and regenerative braking are old concepts. There is really nothing new here. That story is being spread by all manner of web sites whose writers are frothing at their collective mouths. They think it is a new discovery.

The 100 MPG figure is a sales pitch being repeated as if it was gospel.

Hydraulic drives are inefficient, period. They work for UPS because they have a start stop drive cycle, with lots of braking, so a regenerative system may offer some degree of mileage boost. A sporty car driven on the highway is another matter.

Think of how you drive on the highway. Do you brake all the time? If not, then that system is actually going to get worse fuel mileage than if the engine were mated to a conventional transmission. The hydraulic losses have to be paid for somehow.

 

[woodlandfarms]

I really don't disagree with you, and I am stumped by how this could produce 100 MPG at anytime.

That said, I am a lot less cynical than I used to be. I remember people saying a engine / electric generator / motor combination will never work. That we were at the end of Moores Theory, that a simple blender could not provide power for under $200. I am a lot less cynical, I just don't have any money to be gullible, I guess that makes me luckier than I think.

 

[MossRoad]

Have you guys seen the air powered car coming out soon?

http://www.popularmechanics.com/automotive/new_cars/4217016.html

Neat concept. Follow the links for more reading. I saw it on T.V. the other day. A couple years ago we were out in Rapid City S.D. and saw an air powered locomotive from a hundred years ago that was used in mining. Pretty neat, I thought. But seeing all those rivets in that heavy steel tank made me think "too heavy and to much PSI for a car". Think of the explosive power behind a 4000psi steel tank! The air car guy said they get around it by using carbon fiber air tanks that, if ruptured, just split open, releasing the air pressure without much explosive force. They also will have a model with a combustion engine to power a compressor to refill the air tanks on the go. The thing had something like a 600 mile range. Anyhow, neat concept. I'll bet we see more of these than electric cars in the future just because of the battery issues.

 

[SnowRidge]

Have you guys seen the air powered car coming out soon?

Air Car - First Air-Powered Car - Zero Emissions - Behind the Tech - Popular Mechanics

I'll bet we see more of these than electric cars in the future just because of the battery issues.

Moss, did you read the comments on the PM web site? Among other things, it was pointed out that compressed air as a power source is hugely inefficient because of all the waste heat generated.

Compressed air locomotives (and steam locomotives that used stored steam generated elsewhere) were used in situations where the fire and smoke of a conventional steam locomotive would be hazardous. They were very inefficient devices, even more inefficient than conventional steam locomotives of the time, which disappeared rapidly once the diesel engine came onto the scene.

I'm betting we never see compressed air cars used by the general public.

Edit:

BTW, Myth Busters tried using compressed air to power a boat. IIRC, their best effort got the boat to move about ten feet before the boat ran out of air. The crowds were amused.

 

[MossRoad]

Moss, did you read the comments on the PM web site? Among other things, it was pointed out that compressed air as a power source is hugely inefficient because of all the waste heat generated.

Compressed air locomotives (and steam locomotives that used stored steam generated elsewhere) were used in situations where the fire and smoke of a conventional steam locomotive would be hazardous. They were very inefficient devices, even more inefficient than conventional steam locomotives of the time, which disappeared rapidly once the diesel engine came onto the scene.

I'm betting we never see compressed air cars used by the general public.

Edit:

BTW, Myth Busters tried using compressed air to power a boat. IIRC, their best effort got the boat to move about ten feet before the boat ran out of air. The crowds were amused.

The compressed air locomotive we saw was compressed air, not compressed steam.

As for myth busters... those hacks!!!

Early torpedoes used compressed air only and had a range of over a thousand yards, so I'm not sure why they couldn't get that boat to move very far. My my guess is they should have exhausted the air under the water instead of over the water, or they should have used the compressed air to turn an air motor connected to an propeller instead of just blowing it like the wind.

We've all seen (at least I have seen) videos of compressed air tanks getting the ends knocked off of them and then shooting though a brick wall, then going clunk! on the ground. Not much of a range. If, however, you would run the air through an air motor connected to gears to turn wheels and set the air tank on those wheels, I'll bet they could have gotten miles out of that same tank (but it wouldn't have gone through a brick wall and been nearly as fun to have watched).

Tata motors in India is backing this thing. My guess is they will make a go of it and see what happens. The videos of the car running around in the warehouse were cool. Kinda sounded like a mini steam train puffing away.

 

[SnowRidge]

Both compressed air and stored steam were used in the old days in hazardous environments. They both went away as soon as more efficient mechanisms were developed.

Compressed air is only 12% efficient as a power source. It's that bad. Google compressed air efficiency. You will get many hits.

At 12% efficiency, the electric power plant used to generate the power to run the compressors would generate eight times the emissions it would to power an electric car, not to mention using eight times as much fuel. So much for the energy saving zero emissions car that they are touting.

Ditto for an on board engine in a hybrid application.

It's all a bunch of hot (compressed) air.

 

[MossRoad]

Its still neat stuff.

The first one I saw was at this kids' park in Rapid City. It looked like a steam engine without the smokestack. I wondered what it was and read the placard. Here's a link to a page with a bunch of them. The rapid city one is a bright blue color photo about 3/4 of the way down the page.

Compressed-Air Propulsion.

 

[BobRip]

The range of 600 miles was with the use of the gas engine. I can't remember what the compressed air range was but I think about 125 miles. That's not bad, but generating compressed air does have a lot of losses since you can't store the heat. I saw the same show and they sure make it sound promising. Like Moss says time and the market will tell. I am please to see efforts to make other (than internal combustions system) vehicles. If we had a really good battery or super capacitor a lot of things would change. Maybe with enough of our tax dollars this will happen. I have hope anyway if not faith.