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The Race to 100 MPG
PopSci.com ^ | 9/1/2006 | Billy Baker

Posted on 10/25/2006 7:13:52 AM PDT by Red Badger

Jet-Engine Inspiration Another potential player in the race to 100 mpg is the StarRotor, which began life as an air conditioner at Texas A&M University. Chemical-engineering professor Mark Holtzapple and his colleague Andrew Rabroker were attempting to build a better compressor for an air conditioner when they hit on the idea that became the StarRotor engine’s basic architecture. Once they made the connection to car engines, “we quickly forgot about air conditioners,” Rabroker says. They have since formed a business (also called StarRotor) to commercialize the technology.

The StarRotor uses the same thermodynamic process as jet engines to recuperate some of the heat normally lost to exhaust, something that the design of a piston engine doesn’t allow. The exhaust heat warms the air that comes into the engine before the fuel is added [see illustration, below]. This hot air leads to more powerful combustion, which means the StarRotor can extract more energy from a given amount of fuel than a conventional engine could.

Stephen Rountree

Intake air is compressed [A] and heated [B] before it ignites in the combustor [C]. The exhaust spins the rotor [D] that drives the wheels. It then warms the heater [E].

Based on data from compressor prototypes, Rabroker believes the StarRotor will convert between 45 and 65 percent of the chemical energy in its fuel to mechanical energy, irrespective of the engine’s operating speed or power. In contrast, a typical gasoline engine has a peak efficiency of about 30 percent at full throttle and operates at a much lower efficiency during typical driving conditions. “Double is a gimme,” Rabroker says of the StarRotor’s potential. “I think we can ultimately triple the fuel mileage.”

Double or triple, though, what’s important is that innovators are developing solutions to our oil predicament —solutions that could have a huge influence before the first hydrogen-powered car ever leaves the lot.

When Billy Baker isn’t writing about the automotive industry, he’s working on a book about the juggling subculture.



TOPICS: Business/Economy; Miscellaneous; News/Current Events
KEYWORDS: diesel; energy; engine; gasoline; pollution
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Pretty cool looking.........
1 posted on 10/25/2006 7:13:53 AM PDT by Red Badger
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To: sully777; Toby06; vigl; Cagey; Abathar; A. Patriot; B Knotts; getsoutalive; muleskinner; ...
KNOCK-KNOCK!........

If you want on or off the DIESEL "KNOCK" KIST just FReepmail me........

2 posted on 10/25/2006 7:14:43 AM PDT by Red Badger (CONGRESS NEEDS TO BE DE-FOLEY-ATED...............................)
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To: Red Badger

Seal issues. Think Wankel.


3 posted on 10/25/2006 7:15:22 AM PDT by Steely Tom
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To: Steely Tom

I don't wank seals..........


4 posted on 10/25/2006 7:15:55 AM PDT by Red Badger (CONGRESS NEEDS TO BE DE-FOLEY-ATED...............................)
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To: Red Badger

That compressor doesn't look very efficient.


5 posted on 10/25/2006 7:16:38 AM PDT by lesser_satan (EKTHELTHIOR!!!)
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To: lesser_satan

Looks can be "deceiving", lesser_satan.........


6 posted on 10/25/2006 7:17:44 AM PDT by Red Badger (CONGRESS NEEDS TO BE DE-FOLEY-ATED...............................)
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To: Red Badger

It's actually not all that dissimilar from a rotary engine that Mazda RX-7s and RX-8s have.


7 posted on 10/25/2006 7:17:53 AM PDT by JamesP81 (The answer always lies with more freedom; not less)
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To: lesser_satan
http://www.starrotor.com/

Above is the URL of star rotor which explains how it works.
Great graphs and diagrams.
8 posted on 10/25/2006 7:20:12 AM PDT by HuntsvilleTxVeteran ("Remember the Alamo, Goliad and WACO, It is Time for a new San Jacinto")
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To: Red Badger

I think you blew a seal,

no it's just ice cream


9 posted on 10/25/2006 7:27:22 AM PDT by edzo4
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To: Red Badger
I don't wank seals..........

LOL...or blow them.

10 posted on 10/25/2006 7:27:48 AM PDT by Lekker 1 (("...the world will be...eleven degrees colder by the year 2000" -- K. Watt, Earth Day, 1970)
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To: Red Badger

Look promising, of course the proof is in the pudding. They need a working prototype, and need to prove its efficiency in typical automotive use, plus it has to have similar longevity compared to todays piston engine. I wish them the best.


11 posted on 10/25/2006 7:29:00 AM PDT by Paradox (American Conservatives: Keeping the world safe for Liberalism.)
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To: Red Badger

This is a standard turbine engine with a positive displacement compressor and turbine instead of centrifugal. The heat recuperator is nothing new either. Actually, I have often wondered why there hasn't been more development in this technology before.


12 posted on 10/25/2006 7:30:29 AM PDT by Lekker 1 (("...the world will be...eleven degrees colder by the year 2000" -- K. Watt, Earth Day, 1970)
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To: Red Badger
For comparison, other "concept" engines:

Revtec:
http://www.freerepublic.com/focus/f-news/1505350/posts

MYT:
http://www.freerepublic.com/focus/f-chat/1621112/posts

An old one, the Bourke engine (claims 300% more efficiently than 4 stoke engines):
http://peswiki.com/index.php/Directory:Bourke_Engine
13 posted on 10/25/2006 7:31:53 AM PDT by Pete from Shawnee Mission
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To: Red Badger
MASH HERE and discuss.
14 posted on 10/25/2006 7:32:51 AM PDT by isthisnickcool (The City Council of Houston Texas is made up mostly of retards.)
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To: Red Badger

Um...

If it's in production why isn't anyone using it?

If it's in development why would they broadcast their invention before production?


15 posted on 10/25/2006 7:32:53 AM PDT by HarleyD ("Then He opened their minds to understand the Scriptures" Luk 24:45)
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To: JamesP81

The key differences from a wankel that I see are that the combustion takes place away from the moving parts, and the compression and the expansion take place in separate mechanisms. It seems that the "seal" issues of the Wankel may not be as much of an issue here.


16 posted on 10/25/2006 7:34:40 AM PDT by Lekker 1 (("...the world will be...eleven degrees colder by the year 2000" -- K. Watt, Earth Day, 1970)
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To: isthisnickcool
From their webpage...

I guess I answered my own question.
17 posted on 10/25/2006 7:36:46 AM PDT by HarleyD
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To: Red Badger

Looks to me like one of those jet engines you make from an old automobile turbocharger. Just hook a drive shaft up to it...


18 posted on 10/25/2006 7:40:09 AM PDT by Bon mots
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To: Red Badger

What's the bid geal with 100mpg? My mother drives a diesel Citroen C1 which does 83mpg at a steady 56mph. On gentle runs she's got nearly 90mpg. . . . .


19 posted on 10/25/2006 7:40:39 AM PDT by AngloSaxonChristian
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To: Steely Tom
Seal issues. Think Wankel.

Yup... and Wankels are not very fuel-efficient engines to begin with, compared to piston engines of similar horsepower. It looks like they've managed to recapture some waste heat and use it, upping the efficiency, but these claims sound terribly speculative.

Also, what's with the "the exhaust spins the rotor that drives the wheels" part? That sounds a lot like the old Chrysler Turbine setup. The diagram shows no connection between the compression and drive rotors, not even a viscous coupling. The vehicle better be small and light, because I suspect this design will share another Wankel characteristic - low torque. Efficiency is great, but if it can't do the work...

20 posted on 10/25/2006 7:46:21 AM PDT by Charles Martel (Liberals are the crab grass in the lawn of life.)
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