# Jaguar's Turbine-powered Hybrid Electric Supercar



## Pelectric (Oct 14, 2008)

This car looks amazing, the article above doesn't work for me, so for anyone else that is interested, this article on PistonHeads has some more info:

http://www.pistonheads.co.uk/news/default.asp?storyId=22547



















"At the centre of the car sit state-of-the-art, mid-mounted micro gas-turbines. These can either generate 140kW (188bhp) to charge the batteries and extend the range of the car to a remarkable 900km (560 miles) – enough to drive from London to Berlin on a single tank – or when in Track mode provide supplementary power directly to the electric motors."

Has anyone used Micro Turbines for a range extender in an electric car off this site? Would be quite interesting to see the results, anyone know?

Thanks

Pel


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## RE Farmer (Aug 8, 2009)

Pelectric said:


> "At the centre of the car sit state-of-the-art, mid-mounted micro gas-turbines. These can either generate 140kW (188bhp) to charge the batteries and extend the range of the car to a remarkable 900km (560 miles) – enough to drive from London to Berlin on a single tank – or when in Track mode provide supplementary power directly to the electric motors."
> 
> Has anyone used Micro Turbines for a range extender in an electric car off this site? Would be quite interesting to see the results, anyone know?


Another car using a (Capstone) micro turbine is Neil Young's LincVolt 

http://lincvolt.force.com/lincvolt_lincvoltgazette

This is an outstanding and imaginative conversion.


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## Pelectric (Oct 14, 2008)

RE Farmer said:


> Another car using a (Capstone) micro turbine is Neil Young's LincVolt
> 
> http://lincvolt.force.com/lincvolt_lincvoltgazette
> 
> This is an outstanding and imaginative conversion.


Cheers mate, I'll give it a read.


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## aeroscott (Jan 5, 2008)

Pelectric said:


> Cheers mate, I'll give it a read.


 About 1 year ago on Capstones web site was a link to a guy that was linking microturbines together for diesel like effency same as ford did in the 60's he explained the hole thing great . lost the link , called capstone no help .


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## david85 (Nov 12, 2007)

Last I heard, gas turbines have some significant disadvantages over reciprocating engines. Peak efficiency doesn't compare to a diesel (though power to weight is much better) and the peak effieciency is found in a fairly narrow operating range.

I wish they would say more about those turbine engines.

Beautiful car though.


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## Pelectric (Oct 14, 2008)

david85 said:


> Last I heard, gas turbines have some significant disadvantages over reciprocating engines. Peak efficiency doesn't compare to a diesel (though power to weight is much better) and the peak efficiency is found in a fairly narrow operating range.
> 
> I wish they would say more about those turbine engines.
> 
> Beautiful car though.


Apparently, they have 80% efficiency when the heat is used for energy generation aswell, but could the same principle be applied to a reciprocating engine? I couldn't find much on it to be fair so I have no idea.

Jaguar said this about their turbines:

"_With fewer moving parts and air bearings, turbines do not need oil lubrication or water-cooling systems, all of which offers considerable weight-saving benefits. They can also be run on a range of fuels including diesel, biofuels, compressed natural gas and liquid petroleum gas. Turbines reach their optimum operating speed and temperature in seconds and so can be used in short bursts to top up the batteries without compromising fuel consumption or life-cycle._"

Can diesels engines run on any renewable fuel? The thing about not needing oil or water cooling seems great. And they sound good too, the only diesel I have heard that sounds good is the Audi Le Mans Diesel. 

With the power to weight comment, it seems like it would be suited for a very small conversion, that wanted a range extender, like motorbike perhaps, or a tiny car.


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## JRP3 (Mar 7, 2008)

FF GTM hybrid with turbine
http://www.factoryfive.com/whatsnew/press/capstone/text.html


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## JRP3 (Mar 7, 2008)

http://www.teslamotorsclub.com/showthread.php/3858-Blackbird-Turbine-HEV

http://www.teslamotorsclub.com/showthread.php/3042-Micro-jet-turbine-REEV


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## etischer (Jun 16, 2008)

He says the turbine is very high effeciency, the exhaust temperature is around 200F. His licence plate reads 69K RPM!


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## ngrimm (Oct 19, 2007)

Wow, the Jag does 0-100 in 5.5 sec. Subtracting the initial 68 mile all electric range from the 560 miles equals 492 miles and has a 15.8 gallon fuel tank (60 liters) so that is around 31 mpg running on turbine. Considering how heavy that car must be, the turbine's efficiency appears to be pretty good.


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## david85 (Nov 12, 2007)

Pelectric said:


> Apparently, they have 80% efficiency when the heat is used for energy generation aswell, but could the same principle be applied to a reciprocating engine? I couldn't find much on it to be fair so I have no idea.


Correct. While I may never be able to fully suppress my ICE tendancies, one of the things I absolutely hate about them is their net thermal efficiency. Thermal efficiency is the term used because these are heat engines since they convert heat into work. How much of the heat generated that gets turned into usable work is the efficiency of the engine (MPG numbers are meaningless when you examine efficiency within the engine in this manner).

You are absolutely correct that any heat engine is more efficient when waste heat energy is used to generate more work. Diesels are generally around 40% efficient (for highway engines), gas turbines and otto cycle petrol engines are more or less tied at 30%. This does NOT account for things like emission controls, power steering, and power transmission losses between the crank shaft and the road. Over all ICE powered vehicles are very inefficient.

Place a diesel, turbine, or otto engine in a pot of water and you will get more energy out of the heat generated (wasted) than you will from the crank shaft (that example is impossible, but its only for a visual).

Recovering that waste energy is the problem however since no recovery system is completely efficient and the extra equipment is heavy. It works well for stationary power plants but scaling it down small enough for a mobile vehicle is a challenge.



Pelectric said:


> Can diesels engines run on any renewable fuel? The thing about not needing oil or water cooling seems great. And they sound good too, the only diesel I have heard that sounds good is the Audi Le Mans Diesel.


Diesels have a lot in common with turbine engines in how they use their fuel. Both engines run a variable mixture ratio (usually on the lean side of stoichiometric unless something is wrong), and both require high pressure fuel delivery systems to inject fuel into the chamber so it can be burned instantly when exposed to maximum compression. Otto cycle engines do not inject fuel at the top of the compression stroke and rely on a stable mixture ratio via throttle body to produce a stable and complete burn. The injection system alone is a big reason why diesels have always been more expensive to build.

The only thing preventing a diesel engine from running on different fuels other than strait #1 or #2 is the fuel system. The engine itself can easily burn anything that can flow through a pipe and forced through an injector. Lots of guys burn biodiesel, or used engine oil in their older mechanically injected diesels. I'm not advising the practice because that can damage the injection system if done wrong or if a bad batch of "fuel" is used, but if done right it works very well. My truck seems to love the stuff when I tried it a while back. More power, better MPGs and no smoke (engine oil has higher BTUs/ gallon than diesel fuel).



Pelectric said:


> With the power to weight comment, it seems like it would be suited for a very small conversion, that wanted a range extender, like motorbike perhaps, or a tiny car.


I was mainly thinking along the lines of aircraft where weight is very important and has a much more noticable effect on the range or efficiency of the vehicle (which is why you won't see big heavy diesels powering airlines even though thermal conversion efficiency is better for the diesel). Road going machines aren't affected as much but every pound does still add up.

Don't get me wrong, I like turbine engines and would love to get my hands one one of them to tinker with but I just don't see the efficiency numbers adding up.


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## david85 (Nov 12, 2007)

ngrimm said:


> Wow, the Jag does 0-100 in 5.5 sec. Subtracting the initial 68 mile all electric range from the 560 miles equals 492 miles and has a 15.8 gallon fuel tank (60 liters) so that is around 31 mpg running on turbine. Considering how heavy that car must be, the turbine's efficiency appears to be pretty good.


I would have to disagree with that as being impressive. I have a 6000lb diesel pickup that can consistently deliver 24-25 MPG when cruising at 55 MPH. Granted it isn't stock anymore, but still, most of the junk in it is over 20 years old. Considering the horrible drag coefficient and much larger frontal cross section, I would expect the jag to get at least twice the MPGs. Many midsized cars and smaller SUVs can already cruise in the 30 MPG zone these days.

Compact diesel pickups sold in the 1980s could easily reach 40 at those speeds.

Sorry if I'm being a downer about this but other than an interesting project, I don't see the potential here unless they are able to get the efficiency up. As a super car it does have some novelty I guess.


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## Woodsmith (Jun 5, 2008)

I wonder which way the jet exhaust points?

Straight backwards might provide a degree of thrust alongside the driving wheels.


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## ngrimm (Oct 19, 2007)

Once your truck can do 0-100 in 5.5, top out at 205 mph, get 30+ mpg and use no diesel the first 68 miles I too will be impressed What were the early diesel vehicles like before turbos? Now look have far they have come especially with variable geometry turbos to all but eliminate lag. I would be surprised if they weren't able to improve on the turbine/electric combo given a little more time.


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## david85 (Nov 12, 2007)

ngrimm said:


> Once your truck can do 0-100 in 5.5, top out at 205 mph, get 30+ mpg and use no diesel the first 68 miles I too will be impressed What were the early diesel vehicles like before turbos? Now look have far they have come especially with variable geometry turbos to all but eliminate lag. I would be surprised if they weren't able to improve on the turbine/electric combo given a little more time.


I just don't see the point in a 2 seat 3000lb supercar that gets worse fuel economy than the average 5 seat family sedan running on strait gasoline through a conventional powertrain. A diesel sedan or hybrid like the prius will get better still, not to mention the price difference. For all its complexity, I don't see this as any kind of leap forward.

£200,000 can buy you a lot of ....... 











anything! LOL

One final word of caution is this is all coming from press releases so far. I would not believe any of their power, top speed or MPG numbers until verified by an independant body. Vaporware is rampant in the auto industry but unfortunately its even worse when they are trying to look green.

As far as engines evolving over time, you are confusing power with efficiency......


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## aeroscott (Jan 5, 2008)

good posts and the video , capstones run after compressed air threw a heat exchanger to recover exhaust heat so less fuel is needed . 20-25% eff . demonstrated . 200 deg. f. exhaust temp. Single speed , big gear box and great expense in making turbines were given as the reasons for not implementing them in cars and trucks in the 60's . Capstone is configured like turbocharger, centrifugal compressor and turbine wheel (exhaust) tied directly to the generator ( no gear reduction ) . This turbo generator uses air bearing (no oil ) of NASA design . Ford built a semi truck with the turbine / heat exchanger but added second unit , cross plumed the 2 units with valves so different pressures could be seen buy the unit . confused ! this makes the turbine think its at say 30,000 ft. for low power (10%) and then at 20,000 FT. for 30% power, then buy more valve switching sea level (!00%) power. all done at the same turbine speed (max eff.) this made for diesel truck eff . ( 1960's) . So speed / gearbox are no longer a issue for a generator . We now have 3 eff. power levels . We now have the expensive turbine materials and manufacture . Well turbo chargers are using the same materials and speeds for $1000 - 2000 . So the day of the crank shaft should have ended a long time ago . I wish I could find that link , he was much better at describing Fords work and his which was based on using turbochargers . I wonder if The Jag. is cross tying it's 2 units , my bet is yes ! With maybe slightly underszed heat exchangers . I had talked to a turbine engine guy about this system said it was hard get everthing sized right .


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## aeroscott (Jan 5, 2008)

Capstone has made micro turbines for years , lots of them out there . used they go for about $15000 . check out there site I haven't been on it for some time .


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## david85 (Nov 12, 2007)

Found this:

http://www.capstoneturbine.com/_docs/datasheets/C30%20Liquid%20Fuel_331032D_lowres.pdf

Their own numbers are for peak efficiency a little over 25%. I still don't see what the big deal is.



aeroscott said:


> Capstone has made micro turbines for years , lots of them out there . used they go for about $15000 . check out there site I haven't been on it for some time .


Ouch!


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## JRP3 (Mar 7, 2008)

Personally I'd be much more interested in them pulling out the turbines and putting in more batteries.


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## aeroscott (Jan 5, 2008)

Does any one remember the founder of Dell or Compaq . His brother tuck a S class MB exchanged a Capstone turbine and batteries for a big hybrid . 15 or so years ago .


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## aeroscott (Jan 5, 2008)

what I posted in thread #17 came from a link on capstones web site . They said they were working with him on something . It's not a stretch for them to make the same improvements that we done in the 60's adding capstones own improvements and getting diesel eff. The Jag has 2 turbines with heatexchangers , it's just tubing and valves added .


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## PhantomPholly (Aug 20, 2008)

Before everyone gets all excited about another over-unity promise, there are some things you should know about turbine engines.

They are NOT efficient.

Here is a microturbine actually in production. The jet is being produced; the turboprop version is still in development. However, since the engine core is being produced and they provide an estimate of horsepower, it is possible to calculate specific fuel flow (lb/hr/hp). They cleverly conceal their fuel flow using nonstandard power and measure units, but doing the math (Google is your friend) I came out with over 40gph for 250hp. That sucks (pun intended).

To be truly efficient, turbines must operate hot. EGT will be at least 2,000 degrees Farenheit for an efficient turbine. Too, small size works against efficiency in a turbine.

The breakthroughs people have been looking for are ceramics tough enough to spin 100,000rpm in the hot section. Don't believe that is out of science fiction land. Given such "unobtanium," they should be able to get the efficiency nearly as good as ICE.

As for 30mpg - as others have noted, that's not very good. Aerodynamics and rolling friction play a bigger part than weight, and having the vehicle be a hybrid boosts apparent mpg by smoothing out hills and valleys.

Have turbines improved? Naturally. The Phantom sucked down 12,000 lbs/hr per engine at full throttle / sea level before lighting the burners. At sea level and full burner it was gulping nearly 50,000lbs/hr on the ground - giving it only 15 minutes of internal fuel before tanks dry. Today's turbines are certainly better. But, I would be very cautious of claims of efficiency from a microturbine.


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## aeroscott (Jan 5, 2008)

PhantomPholly said:


> Before everyone gets all excited about another over-unity promise, there are some things you should know about turbine engines.
> 
> They are NOT efficient.
> 
> ...


 find a book on turbine engines , most will talk about heat exchanged turbines . A lot of the peaking power plants run buy the utilities run turbine power plants . Capstone has 5000 units in the field . You refer to an aero turbine which has no heat exchanger . one of the turbochargers was using ceramic hot wheels 10 years ago . Did you read about the Volvo ceramic turbine generator with heat exchanger built about 10 to 15 years ago for a hybrid concept car .


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## david85 (Nov 12, 2007)

The only thing I ever heard about ceramic turbochargers was they were more fragile and could break but they were more heat resistant and could spool faster. This allowed the engine to safely run higher EGTs and adapt to variable engine operating conditions without suffering as much economy loss. 

AFAIK, all turbochargers that are used on production vehicles use inconel alloy exhaust turbine and entegral shaft with an aluminum alloy compressor wheel that bolts on. Using ceramic for the compressor side would be dangerous since a blow out would send the shards into the engine. Cost was probably a factor too.

Ceramic ball bearings are starting to make their way in but I don't think ceramic was ever considered safe enough for the turbine or compressor wheels on a production car unless you can tell me otherwise.

At any rate, 30 MPG for a 2 seat 3000lb car is still nothing to write home about.


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## aeroscott (Jan 5, 2008)

they were on a Japanese import not a rare car . another Google let down . just making hotter turbines alone doesn't help eff. , compression ratios have to increase along with temp . the later big turbines have 40/1 compression ratios . they also blow compressor air through the inside of the blades and out over the surface to cool the blades . monocrystalline and directional solidification cast superalloys have allowed temps and pressures to come up dramatically , with it eff. small engines all suffer form low volume to surface ratios , the same with seal leakage . We now have fords turbine , Volvo's turbine , capstones turbine and host of other planned turbines . Why especially Fords turbine can we not get in depth information on the design ( I hve sean it on the net) , other then books and threw membership to engineering societies . The same story with the power grid , we get a cover story from a DOE politician . In that case all I was looking for was the combined line loss / mile ( hysteresis and resistance ) . I did find the resistance (the one that matters the least)


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## PhantomPholly (Aug 20, 2008)

aeroscott said:


> find a book on turbine engines , most will talk about heat exchanged turbines . A lot of the peaking power plants run buy the utilities run turbine power plants . Capstone has 5000 units in the field . You refer to an aero turbine which has no heat exchanger . one of the turbochargers was using ceramic hot wheels 10 years ago . Did you read about the Volvo ceramic turbine generator with heat exchanger built about 10 to 15 years ago for a hybrid concept car .


LOL - I spent two years training to fly jet fighters - we read LOTS of books on turbine engines.  And, I do try to keep up on the latest innovations - in the experimental aviation world (I fly a Lancair) there are literally thousands of enthusiasts looking for an alternative to the 1940's technology "Lycosaurus" ICE piston engine. While it is possible that something has escaped my notice, my guess is that either a) the efficiency is still not an improvement over existing engines or b) the price is still in the "exotic" range...

As I pointed out, ceramic turbines have the POTENTIAL to run at much greater temperatures and thus achieve greater efficiencies. However, I have not heard of a successfully mass-produced microturbine that achieves anywhere near the tried-and-true 0.4 lbs / hr / hp of conventional engines run Lean of Peak EGT (the most efficient mixture for an ICE).

But... I'd be exited to hear I am wrong, and would love to be the first to spread the word in the experimental world! Please provide a link if you have one.


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## PhantomPholly (Aug 20, 2008)

david85 said:


> The only thing I ever heard about ceramic turbochargers was they were more fragile and could break but they were more heat resistant and could spool faster. This allowed the engine to safely run higher EGTs and adapt to variable engine operating conditions without suffering as much economy loss.
> 
> AFAIK, all turbochargers that are used on production vehicles use inconel alloy exhaust turbine and entegral shaft with an aluminum alloy compressor wheel that bolts on. Using ceramic for the compressor side would be dangerous since a blow out would send the shards into the engine. Cost was probably a factor too.
> 
> ...


Don't know if you were responding to the topic of turbine ENGINES - turboCHARGERS are a whole different animal.

Turbochargers help an ICE attain higher hp/lb, gaining the extra hp "for free" (if properly configured) by scavenging energy from the exhaust to compress incoming air. If properly intercooled (more cooling drag), higher hp/weight ratios can be obtained but generally at the expense of higher wear / greater failure rates for the engine. TANSSAAFL.

Turbine (jet) engines use a different combustion principle; produce a great deal of hp/weight with great reliability; but (currently) at a heavy fuel consumption penalty / hp generated. 

Edit: The reason they make sense for jet aircraft is that their immense power-to-weight ratio helps propel the aircraft upwards of 40,000', where the air is 1/3 to1/4 as dense as it is down at sea level. Lower pressure = lower thrust = lower fuel burn; they size the engine for the jet so that at those altitudes the turbine is near it's most efficient and producing just enough to propel the aircraft at ITS most efficient airspeed (a bit faster than "best glide" airspeed, which at high altitude is approaching Mach). Most of the fuel burned by an airliner is in climb. That's why there's little difference in ticket price between a short hop and a longer haul - an airliner may not burn much more in cruise between New York and Denver than it burned just getting up to altitude, and the descent is "nearly free."


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## ngrimm (Oct 19, 2007)

I don't know anything about anything so I'll ask a few questions. 1. Why did Jaguar go thru the trouble and expense designing this car? 2. Are there any current ice hybrids out there that claim to have the the ev range and performance combinations that Jag is claiming? Does Jag have a history of creating cars that fall FAR short of their claims? Are their engineers less intelligent or informed about turbine efficiency than everyone else? Is every one that does something different than me automatically guilty of conspiracy since I don't know exactly how they did it? I don't get the over unity comparison since even if the ice engine was 100% efficient it would still require gasoline unless it was plugged in to recharge.


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## sunworksco (Sep 8, 2008)

The East Indians who own Jaguar have great financial resources to attract the most brilliant engineers.The great design of this micro turbine hybrid is the fact that jet fuel is everywhere on the planet , even bio-jet fuel.Take a gander at Jay Leno's bio-fuel turbine car : 
http://www.popularmechanics.com/cars/jay-leno/green-garage/4334674

Now if they add to their design a heat exchanger to convert the waste heat into electricity they will have the perfect power plant :

Bismuth telluride is a narrow gap layered semiconductor with a trigonal unit cell. The valence and conduction band structure can be described as a many-ellipsoidal model with 6 constant-energy ellipsoids that are centered on the reflection planes. Bi2Te3 cleaves easily along the trigonal axis due to Van der Waals bonding between neighboring tellurium atoms. Due to this, bismuth telluride based material that is used for power generation or cooling applications must be polycrystalline. Furthermore, the Seebeck coefficient of bulk Bi2Te3 becomes compensated around room temperature, forcing the materials used in power generation devices to be an alloy of bismuth, antimony, tellurium, and selenium.

Recently, researchers have attempted to improve the efficiency of Bi2Te3 based materials by creating structures where one or more dimension is reduced, such as nanowires or thin films. In one such instance n-type 
N-type semiconductor
N-type semiconductors are a type of extrinsic semiconductor where the dopant atoms are capable of providing extra conduction electrons to the host material...

bismuth telluride was shown to have an improved Seebeck coefficient (voltage per unit temperature difference) of −287 μV/K at 54 Celsius, However, one must realize that Seebeck Coefficient and electrical conductivity have a tradeoff; a higher Seebeck coefficient results in decreased carrier concentration and decreased electrical conductivity.

In another case, researchers report that bismuth telluride has high electrical conductivity 
Electrical conductivity
Electrical conductivity or specific conductance is a measure of a material's ability to conduct an electric current. When an electrical potential difference is placed across a conductor, its movable charges flow, giving rise to an electric current...

of 1.1×105 S·m/m2 with its very low lattice thermal conductivity 
Thermal conductivity

In physics, thermal conductivity, , is the property of a material that indicates its ability to conduct heat. It appears primarily in Fourier's Law for heat conduction. Thermal conductivity is measured in watts per kelvin per metre...

of 1.20 W·m/(m2·K), similar to ordinary glass 
Glass

Glass is an amorphous solid material. Glasses are typically brittle, and often optically transparent. Glass is commonly used for windows, bottles, and eyewear; examples of glassy materials include soda-lime glass, borosilicate glass, acrylic glass, sugar glass, Muscovy-glass, and aluminium...

Regards,
John


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## aeroscott (Jan 5, 2008)

PhantomPholly said:


> LOL - I spent two years training to fly jet fighters - we read LOTS of books on turbine engines.  And, I do try to keep up on the latest innovations - in the experimental aviation world (I fly a Lancair) there are literally thousands of enthusiasts looking for an alternative to the 1940's technology "Lycosaurus" ICE piston engine. While it is possible that something has escaped my notice, my guess is that either a) the efficiency is still not an improvement over existing engines or b) the price is still in the "exotic" range...
> 
> As I pointed out, ceramic turbines have the POTENTIAL to run at much greater temperatures and thus achieve greater efficiencies. However, I have not heard of a successfully mass-produced microturbine that achieves anywhere near the tried-and-true 0.4 lbs / hr / hp of conventional engines run Lean of Peak EGT (the most efficient mixture for an ICE).
> 
> But... I'd be exited to hear I am wrong, and would love to be the first to spread the word in the experimental world! Please provide a link if you have one.


I have a lancair 235 ground looped that I bought for a hot roded diesel installation . What model do you have . I've been a eaa member since the 80's . Heat recuperator turbines are not talked about in aero circles . there in the standard book on turbines for a&p's has a picture of one I think it's called turbine technology.Ford , Volvo ,capstone , etc. have built or are building (Jag/ capstone) recuperator turbines ( post compression air heat exchanged with the exhaust gases to raise pre combustion air temp. now less fuel is burned to get to the desired temp. ) just as on a hot day you cannot put as much fuel into a turbine engine as on a cold day (less power for two reasons less lbs. of air going in and at a higher temp , exhaust temp has a fixed max.) As I said before utility peaking turbines use heat recuperators , sound engineering principles . Capstones claims 25% eff. with 5000 units sold over 10 years in production . I don't see auto engines doing better then 25% , closest thing to that would be miller cycle with direct injection , maybe a little better. I can't think how to % eff. to .4 lbs/hp/hr . but my diesel runs .35 to .38 and is direct injected . Of corse all diesels run lean of peak. ps capstones web page .


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## david85 (Nov 12, 2007)

Phantom, I compltetly agree about the merits of deploying turbine or turbojet engines to aircraft for the sake of power to weight (and compact size). This is one of a few reasons why conventional diesel engines would be a poor match even if thermal efficiency is higher.

Cars only have to accelerate up to cruise speed. Planes need to accelerate THEN climb to a sustained altitude. Planing hull boats have similar problems when it comes to more weight which is why it can be much harder to build a diesel or electric speedboat that has respectable endurance (not saying its impossible, just more challenging than simply bolting on a V4 outboard).

One silly question here is what sort of emission controls would such a turbine engine need? Do they need any at all or is the exhaust clean enough to pass current standards? If so that could put turbines in an advantage over the otto cycle piston engine.


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## aeroscott (Jan 5, 2008)

PhantomPholly said:


> Don't know if you were responding to the topic of turbine ENGINES - turboCHARGERS are a whole different animal.
> 
> Turbochargers help an ICE attain higher hp/lb, gaining the extra hp "for free" (if properly configured) by scavenging energy from the exhaust to compress incoming air. If properly intercooled (more cooling drag), higher hp/weight ratios can be obtained but generally at the expense of higher wear / greater failure rates for the engine. TANSSAAFL.
> 
> ...


 turbines are a different combustion principle . My point is that a turbocharger is a turbine engine if a combustion chamber is added .the cost of a turbine would be a $1000 + fuel control , combustion chamber and heat exchanger . they spin at the same speed , compress air , extract energy from high temp / pressure exhaust and are made from the same materials . Others have made turbines from turbo chargers , but not very controllable and no way to get power from them . If I remember right the latest big turbo shaft engines (1000 -3500 hp ) run at .3 lbs. / hp/hr. 30 or 40 to 1 conpression ratios ,internal air cooled blades .


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## aeroscott (Jan 5, 2008)

david85 said:


> Phantom, I compltetly agree about the merits of deploying turbine or turbojet engines to aircraft for the sake of power to weight (and compact size). This is one of a few reasons why conventional diesel engines would be a poor match even if thermal efficiency is higher.
> 
> Cars only have to accelerate up to cruise speed. Planes need to accelerate THEN climb to a sustained altitude. Planing hull boats have similar problems when it comes to more weight which is why it can be much harder to build a diesel or electric speedboat that has respectable endurance (not saying its impossible, just more challenging than simply bolting on a V4 outboard).
> 
> One silly question here is what sort of emission controls would such a turbine engine need? Do they need any at all or is the exhaust clean enough to pass current standards? If so that could put turbines in an advantage over the otto cycle piston engine.


 they run very clean no controls needed like blower furnaces the same thing . always run lean , about as clean as you can burn fuel . I would think the big supper high compression units would have a nitrogen oxide output with that high temp/pressure .


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## david85 (Nov 12, 2007)

aeroscott said:


> they run very clean no controls needed like blower furnaces the same thing . always run lean , about as clean as you can burn fuel . I would think the big supper high compression units would have a nitrogen oxide output with that high temp/pressure .


Yeah the higher combustion temps are what get the nox counts up there but can reduce CO and hydrocarbon emissions. In terms of emissions, Nox is the achilles heel of the diesel engine. I'm just not sure if thats a big enough drawback to justify burning more fuel at 25% efficiency. If they can get them into the low 40s, then that would be very significant.

But if they really don't require any emission controls, they could probably compete with 4 cycle gas engines right now provided the cost can be brought into line.


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## aeroscott (Jan 5, 2008)

david85 said:


> Yeah the higher combustion temps are what get the nox counts up there but can reduce CO and hydrocarbon emissions. In terms of emissions, Nox is the achilles heel of the diesel engine. I'm just not sure if thats a big enough drawback to justify burning more fuel at 25% efficiency. If they can get them into the low 40s, then that would be very significant.
> 
> But if they really don't require any emission controls, they could probably compete with 4 cycle gas engines right now provided the cost can be brought into line.


 Nox is a problem with unburned hydrocarbons making ozone . this is what the pro diesel camp says . CARB says it's the Nox it's self . A big scandal went down say 6 months ago about CARB hiring a degreed engineer (Internet degree $ ) He was to make diesels look worse then they are . He tried to submit real reports to carb but they wanted a more pessimistic view of diesel engines so he gets the message and submits the bad report and paid big bucks are paid . this all comes to light and carb says it doesn't change anything . Carb had done a study called the weekend study , checking Nox making ozone in L.A. on the weekend (less diesel trucks) so less ozone . worked the other way higher ozone levels on the weekend .I was told carb would get hot if you asked about it . I don't have personal knowledge of this but it has the ring of truth to it. If diesel type fuel is run in a turbine and is a little higher in consumption this would be offset at the refinery because of higher energy needed to synthesize gasoline. I heard of 2 or 3 gallons to make 1 of gas ( energy would come from natural gas, alot cheaper I would think ) I have no way of checking this .


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## aeroscott (Jan 5, 2008)

I do a lot of short runs . heating all that engine , turbo, water, oil, takes a lot more to get to eff. temps then a turbine does . saving and small amount of fuel many times . unless as hybrids get bigger batteries you would do less start ups .David85 I missed part of your post CO and hydrocarbons bought are low doe to lean burning and continuous burn


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## david85 (Nov 12, 2007)

I read about that CARB - diesel incident recently on a climate skeptic blog (linked to a newspaper article in San Fransisco). I have maintained for a long time that CARB and the EPA have gone too far in how they have cracked down on diesel engines since 2007 but never thought they actually cooked the books to do it. Still not sure what to make about that incident but considering they fired one of the lead authors who faked his credencials, I have to wonder as to the validity of the conclusions. But alas, CARB is an unelected organization (so is the EPA for that matter) so they can pretty much do what they want even if this is a red handed situation.

My understanding was that Nox is produced from high temperature burn inside the engine when naturally present nitrogen from the atmospheric intake charge can combine with oxygen (I don't remember what that temperature thresh hold is). I read that a really (REALLY) long time ago in an even older grade 10 science course so who knows how true it is There were other things in that course that didn't pass the smell test but thats another story.

I heard from another unverified source that preignition problems that can occur from running a gasoline engine on the lean side of stoich can also lead to higher NOx emissions and thats why most manufacturers err on the side of running the engine slightly on the rich side of ideal even though it kills some economy. I remember some one on another forum claimed to be getting a little over 20 MPG from his gasoline powered suburban due to some ECM tuning which leaned out the fuel mixture ratio. He produced his emissions test ticket which was a pass but was still showing slighly higher Nox counts than before the modding.

I agree completely about warmup time being a killer with diesels MPGs. My 3/4 ton pickup will deliver MPGs in the low to mid 20s when its warm but for short trips around town it can get into the low teens. I remove the cooling fan in the winter to try and reduce this slightly.

1000lbs of cast iron, 5 gallons of coolant and 2.5 gallons of oil do indeed take a little while to warm up. Sometimes I'll use the block heater before a long trip and it does show up on the end of day MPG calculation. I try as much as possible to drive the EV for those shorter trips for this reason among others.

Newer diesels are smaller and lighter with more aluminum alloy which helps reduce the warm up period but I can see how a turbine is still ahead.


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## aeroscott (Jan 5, 2008)

david85 said:


> I read about that CARB - diesel incident recently on a climate skeptic blog (linked to a newspaper article in San Fransisco). I have maintained for a long time that CARB and the EPA have gone too far in how they have cracked down on diesel engines since 2007 but never thought they actually cooked the books to do it. Still not sure what to make about that incident but considering they fired one of the lead authors who faked his credencials, I have to wonder as to the validity of the conclusions. But alas, CARB is an unelected organization (so is the EPA for that matter) so they can pretty much do what they want even if this is a red handed situation.
> 
> My understanding was that Nox is produced from high temperature burn inside the engine when naturally present nitrogen from the atmospheric intake charge can combine with oxygen (I don't remember what that temperature thresh hold is). I read that a really (REALLY) long time ago in an even older grade 10 science course so who knows how true it is There were other things in that course that didn't pass the smell test but that's another story.
> 
> ...


 what's your truck , mine is 92 dodge with a 96 215hp engine and gear vendor + 5 speed , just found out I'm a little low on fuel pressure leading to retarding of timing , replacement of spring should do it . My fan is huge should try for electric . hybridising would or could help with less worm up. even with 10 mile range my fuel would be a big cut . I just pulled a benz 87 300 d turbo , what a job reminds me of how complex ic engines are .makes me lust for ev with a turbine gen set , maybe someday .


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## david85 (Nov 12, 2007)

aeroscott said:


> what's your truck ,


Thats a big question there lol.

Truck is a 1986 ford F250. Stock setup is a non turbo 6.9L diesel with 4.10 gears and 3 speed slusher. This setup was good for up to 13 MPG on a good day That was also running on the old high sulfur diesel

Has the same engine now but with slightly dropped compression, ARP studs, turbo and thinking of a custom torque cam this winter if time permits.

The very first mod was swapping from 4.10s to 3.08s and that got me into the high teens. I did this swap 3 weeks after buying the truck. 13 MPG? eff that!

Later came the turbo which changed nothing for empty runs but did help when towing for power and econonmy. Exhaust smoke dropped as well.

Then I installed a 4 speed overdrive automatic with locking torque converter (which like the engine, I custom built to my own specs). That allowed me to consistently cruise at 70 MPH and 20 MPG empty even in non perfect conditions. Final drive ratio is 2.18:1 in overdrive. I know some one on another forum running a similar truck with the same transmission, 3.55 gears and a GV overdrive. Final drive of 1.8:1. I'm sure there is a cross over where the results of going with taller and taller gearing do not help anymore but I'm not sure where that is yet.

Last "trick" was to force myself to cruise at 55 MPH instead of above 70 (~1200 RPM). That was when the real numbers started coming in and I got consecutive fillups between 24 and 25 MPG under identical conditions on the same route averaged for both directions on a length of 100+ miles of highway.

I have an identical F150 of the same year and I'm toying with the idea of converting it to diesel too. Its lower to the ground and a good 1500lbs lighter. Maybe with 2.73 or 2.5 gears.....have to finish the EV first.



aeroscott said:


> mine is 92 dodge with a 96 215hp engine and gear vendor + 5 speed , just found out I'm a little low on fuel pressure leading to retarding of timing , replacement of spring should do it . My fan is huge should try for electric .


I know some that have done it with used OEM ford electric fans made by siemens. These are BLDC motors and can move a lot of air if used in twins although some rare crown vics have single fans that are big and powerful enough to work in a single. There may be similar options out there from other brands. However if you have a cummins, there may be better aftermarket support than for my engine. I've heard of guys that tried aftermarket fans and found them to be too weak, unreliable, or both.



aeroscott said:


> hybridising would or could help with less worm up. even with 10 mile range my fuel would be a big cut . I just pulled a benz 87 300 d turbo , what a job reminds me of how complex ic engines are .makes me lust for ev with a turbine gen set , maybe someday .


The EV1 had a prototype like that and there was also a more recent attempt by some university. There is a youtube video of it out there but not much details. I have no idea if this is indeed a series hybrid or something else.
Supposedly the original prototype hybrid EV1s were built in 3 versions, gasoline, diesel, and gas turbine. All of them were over 70 MPG if I remember right.





 
Its hard to argue with the simplicty of an pure EV though. I can tear all of the EV systems out of my car from the batteries to the motor and transaxle assembly in 3 hours. I had to replace a shreaded flexplate in my truck a few months back and that was a 2 day job. Not to mention a lot more messy and harder working underneath. But until I can build an electric truck that can tow for 200 miles or more, I'm stuck with diesels.


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## aeroscott (Jan 5, 2008)

david85 said:


> Thats a big question there lol.
> 
> Truck is a 1986 ford F250. Stock setup is a non turbo 6.9L diesel with 4.10 gears and 3 speed slusher. This setup was good for up to 13 MPG on a good day That was also running on the old high sulfur diesel
> 
> ...


sounds like you done great things with the ford , the e fan is the right direction .bldc I had no idea of . I've slowed down and started drafting , at 55 1300rpm may be to low but 400+ d. f. egt's at 65 550 d.f. , 3.55 rear end and 4x4 . I have one of those 35kw mill turbine gen sets I should start the thing up and see how it works , I also have a pair of stainless steel heat exchangers (air to air ) from mill. aircraft air conditioning(about 1.5 cubic ft and 60 lbs) , if I could plum one to the turbine mite have something . no capstone but fun to see what it would do . I was warned that heat exchanger is no easy endeavor .I was told these units burned 15 -18 g/hr. but that they made 100 hp not sure about fuel burn at what power. experimenters put them in one airplane and a small helicopter. Oh cool vid !


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## david85 (Nov 12, 2007)

My pyro is shot at the moment but last I checked the cruising EGTs were 550F but that was before my 55 MPH tests. Even when towing, it rarely went above 800 unless I was trying to even the score with a steep hill.

Never tried drafting yet since its really hard to get consistent results for verification. I try as much as possible to repeat identical results over and over again to be sure the numbers arent a fluke from filling up or some other variable.


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## aeroscott (Jan 5, 2008)

David, is your prob before turbo like mine , I never supported my egt wire and it will fail too . I can see a small drop in egt's running 1.5 sec behind a simi . I had run Micheline's 245/70Ex16's but added alu wheels and 265/75Dx16's not near as good of tire life . then went 265/75Ex16 these 10 ply rated tires a so heavy you could feel it. I'm trying to figure what is the best size and make . heard that Yokohama's were unbeatable and cheaper .


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## david85 (Nov 12, 2007)

Pre turbo. The whole turbo kit and pyro were bought used a few years ago for $200, so they don't really owe me much. I've been meaning to get a new pyro but never got around to it yet. I still have to get meters for the EV too.....

I'm running the stock tire size of 235/85/16 (10 ply). Toyo open country highway ribbed tires and I run them at 70 PSI. These are relatively narrow for their diameter and that helps a little too. Nice tires but since these are the first new set I bought in my life, I'm not an expert in that regard.


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## aeroscott (Jan 5, 2008)

I was looking at toyo used to get buy , but it's 265/75E 3000+lbs per tire . dam springs can probably handle it and kill my but at the same time .I don't carry big loads that often . 12000+ gross is way over what the dana 60 & 70 can handle with out re cutting/welding the bearings surfaces every few years . Been threw that with the Dana 70 . All this heavy duty stuff is so delicate , example : I had a 1500 lb load in back and was putting along @ 5mph and bumped the curb , that put .006" out of ture in the front hub flange (bolt circle) . So now the brake rotor would run out at least .012" or more run out . Brake rotor indexes to hub (lug bolt circle dia.) Put a new rotor on this hub and after turning rotor it will be so out of balance and the mass change will cause the new true running rotor to warp in a few hot stops . So much for heavy duty 4x4's . I was thinking about the Nox hydrocarbon thing you mentioned , and if say a 1% increase in fuel burn ( to help decrease that deadly Nox ) would make extra billions in oil revenues and make more ozone( if in fact the ozone is a Nox plus hydrocarbon combination ) in the end .


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## david85 (Nov 12, 2007)

I know what you mean. Its a night and day difference in ride quality between my F150 and my F250 even though both are identical bodystyle, frame and model year. Although I have to say, when I got the toyo tires new, there was a noticable improvement in ride for the F250. Not sure if its to do with how the tire was made or if its simply because it was brand new with rubber that isn't aged.

For emissions a 1% drop in fuel economy is a very easy sacrifice to make for better emissions but unfortunately, the sacrifice is much larger. Right around 2007 came diesel particulate filters that killed a solid 40% of fuel economy right out of the box. Urea injection allows higher EGTs so you don't get as much carbon particulates (and thus fewer regen cycles of the DPF which eats all that fuel). The urea is used to then treat the exhaust stream so it consumes the Nox counts. You can tell when a truck goes into regen by the big cloud of raw fuel pouring out the tailpipe. Once its burning it clears up but you can still catch the scent of if. Diesel fumes smell different when they are coming out of a space heater or some other constant flame burn.

While on the one hand, newer urea equipped trucks are pushing above the 20 MPG mark again, now you are forced to buy a second fuel for the emission system which is refined out of cow urine. Try wrapping your head around that one!


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## PhantomPholly (Aug 20, 2008)

sunworksco said:


> The East Indians who own Jaguar have great financial resources to attract the most brilliant engineers.The great design of this micro turbine hybrid is the fact that jet fuel is everywhere on the planet , even bio-jet fuel.Take a gander at Jay Leno's bio-fuel turbine car :
> http://www.popularmechanics.com/cars/jay-leno/green-garage/4334674


Well it's certainly fun - but Jay admits it's not really ecological:



> "I'll admit the fuel economy isn't great. The glass cockpit has a fuel-flow meter, and the EcoJet idles at 8 to 9 gallons per hour. At 70 mph we burn 14 gph, and at full throttle it burns around 57 gph. Remember, this is a jet." - Jay Lenno


That's not to mention the bad press he must get from his neighbors concerning the NOISE!


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## PhantomPholly (Aug 20, 2008)

david85 said:


> Phantom, I compltetly agree about the merits of deploying turbine or turbojet engines to aircraft for the sake of power to weight (and compact size). This is one of a few reasons why conventional diesel engines would be a poor match even if thermal efficiency is higher.
> 
> Cars only have to accelerate up to cruise speed. Planes need to accelerate THEN climb to a sustained altitude. Planing hull boats have similar problems when it comes to more weight which is why it can be much harder to build a diesel or electric speedboat that has respectable endurance (not saying its impossible, just more challenging than simply bolting on a V4 outboard).
> 
> One silly question here is what sort of emission controls would such a turbine engine need? Do they need any at all or is the exhaust clean enough to pass current standards? If so that could put turbines in an advantage over the otto cycle piston engine.


Current aircraft engines do not bolt on emissions junk. Improvements in combustion have reduced emissions / improved efficiency - and low-sulphur rules have eliminated one of the biggest complaints about jet exhaust (that sulphur dioxide was being released in the upper atmosphere). 

The entire Aviation fleet uses a bit less than 10% of all vehicular fuel, and turbine aircraft engines consume well over 90% of all aviation fuel. Thus, small gasoline engine aircraft consume < 1% of all of the gasoline burned each year - which is why they aren't considered enough of a problem to force GA to add catalytic converters. Too, they don't spend much time at idle but run mostly at optimum combustion settings - so they pollute far less than a typical automobile without such junk. 

Jets, like diesels, have a pretty thorough combustion cycle (partly because they have higher combustion temps) - so overall the GA (General Aviation) fleet does not contribute horribly to pollution.

So far as I know, the only emissions controls currently on aviation concern the fuel.


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## PhantomPholly (Aug 20, 2008)

aeroscott said:


> turbines are a different combustion principle . My point is that a turbocharger is a turbine engine if a combustion chamber is added .


Fair enough - just missed where you were going with that. It's probably a bit more complex than that, but close enough.



> the cost of a turbine would be a $1000 + fuel control , combustion chamber and heat exchanger . they spin at the same speed , compress air , extract energy from high temp / pressure exhaust and are made from the same materials . Others have made turbines from turbo chargers , but not very controllable and no way to get power from them . If I remember right the latest big turbo shaft engines (1000 -3500 hp ) run at .3 lbs. / hp/hr. 30 or 40 to 1 conpression ratios ,internal air cooled blades .


Hehe - I'm going to fall back on my standard response: If it were that easy, someone would have done it. Believe me, I know PLENTY of people including NASA jet engineers who wish it were that simple. 

You can in fact make a functioning jet that way. It just will be incredibly inefficient and underwhelming in power.


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## PhantomPholly (Aug 20, 2008)

david85 said:


> Yeah the higher combustion temps are what get the nox counts up there but can reduce CO and hydrocarbon emissions. In terms of emissions, Nox is the achilles heel of the diesel engine. I'm just not sure if thats a big enough drawback to justify burning more fuel at 25% efficiency. If they can get them into the low 40s, then that would be very significant.
> 
> But if they really don't require any emission controls, they could probably compete with 4 cycle gas engines right now provided the cost can be brought into line.


Flight is more complex than rolling a vehicle, and the "theoretical efficiency" of a jet engine is only one factor in determining the overall efficiency of a total system ("the system that delivers people from point a to point b in the minimum time").

Piston engines suffer dis-economy of scale as they get larger (less hp/wt), and propellers have limitations on the maximum airspeed attainable at good efficiency. Thus, the overall efficiency of a piston engine + propeller may not be much better than a jet at 0.5 Mach, and simply cannot attain 0.9 Mach as modern airliners do. Too, large piston engines running as aircraft engines do (almost continuously at 75% of max rated power) are horrifically unreliable when compared to a turbine. The total inefficiency of the system, in fact, boils down to economics - which combines the combustion efficiency with the ancillary costs associated with the total cost of operation over the life of the craft.

Bottom line: You can't just look at fuel burn in operation. It also costs "energy" (imperfectly reflected in maintenance costs) to operate the alternatives to turbines.


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## aeroscott (Jan 5, 2008)

thanks for bringing us back to point . My point about is high production numbers of the turbo make it cheap , engineering costs are cheap when numbers would be so high . MB spends 1 million per day on r&d . This could be one size fits all . making it the highest engine production in history . But this is not the best model for auto profits , same for ev's .


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## david85 (Nov 12, 2007)

PhantomPholly said:


> Flight is more complex than rolling a vehicle, and the "theoretical efficiency" of a jet engine is only one factor in determining the overall efficiency of a total system ("the system that delivers people from point a to point b in the minimum time").
> 
> Piston engines suffer dis-economy of scale as they get larger (less hp/wt), and propellers have limitations on the maximum airspeed attainable at good efficiency. Thus, the overall efficiency of a piston engine + propeller may not be much better than a jet at 0.5 Mach, and simply cannot attain 0.9 Mach as modern airliners do. Too, large piston engines running as aircraft engines do (almost continuously at 75% of max rated power) are horrifically unreliable when compared to a turbine. The total inefficiency of the system, in fact, boils down to economics - which combines the combustion efficiency with the ancillary costs associated with the total cost of operation over the life of the craft.
> 
> Bottom line: You can't just look at fuel burn in operation. It also costs "energy" (imperfectly reflected in maintenance costs) to operate the alternatives to turbines.


Oh I agree completely that there is more to consider than strictly thermal efficiency when it comes to deploying an engine to an airframe. Power to weight ratio was simply one of the more obvious reasons you won't find a diesel engine propelling an airliner.


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## PhantomPholly (Aug 20, 2008)

aeroscott said:


> thanks for bringing us back to point . My point about is high production numbers of the turbo make it cheap , engineering costs are cheap when numbers would be so high . MB spends 1 million per day on r&d . This could be one size fits all . making it the highest engine production in history . But this is not the best model for auto profits , same for ev's .


Actually, there is a very good argument to be made for "one size fits all" if that size is very small - AND if you are the company that sells the "one size" motor. For example, if someone could develop a compact, inexpensive, efficient, 5 lb / 20 hp engine of any operating principle (jet/diesel/whatever), then those could be manufactured by the millions and "chained" for particular applications. I'm still in love with magnetic gears; at such high efficiency there's no reason not to have 20 or more motors chained together and geared for whatever your particular application is. In theory, 20hp would actually be enough for a hybrid with unlimited range for most passenger cars. An airplane with 20 such motors would likely be far more reliable than one with a single motor.

For several years, Freedom Motors has been trying to become that "one size fits all" motor maker. Whether it's them or someone else, it's time for something new.


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