The future of Internal Combustion Engines?
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The future of Internal Combustion Engines?
Just came across this:
"The MYT™ (Massive Yet Tiny) Engine, is a breakthrough of immense
proportions that will spawn the next industrial revolution and will rocket the internal combustion engine into the next millennium. Please spread the word."
http://www.angellabsllc.com/index.html
"The MYT™ (Massive Yet Tiny) Engine, is a breakthrough of immense
proportions that will spawn the next industrial revolution and will rocket the internal combustion engine into the next millennium. Please spread the word."
http://www.angellabsllc.com/index.html
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$0.02 worth of technical analysis.
My initial reaction is that 150mpg is at best optimistic 
. My VW 4 cyl diesel averaging 70mph over 500 miles gets roughly 50mpg. An engine with an equivalent of 32 pistons will offer greater surface area (about 4 times) for the same displacement to loose heat. If 20% heat loss is through the radiator of my VW, then a very quick calc indictes that this would go up to about 50% heat loss - so 50mpg becomes approx 31.25mpg...
Large displacement iron block 6-cyl truck engines are not a fair comparison for mass either, since they are designed for 15'000 cost effective hours of extreme conditions before overhaul. A better package, especially for small displacement, would be two large diam pistons per arm (or whatever it is called). That crank mech looks relatively complicated too, so the only weight saving i see is in the block/head casting mass (worth considering though).
The main problem with this type of design is always emissions. Like a uniflow scavenge 2-stroke, you need to keep the rings oiled. This means that there is a steady leakage of oil from the exhaust valve. 4-stroke poppet valves are a compromise, but they do work.
I notice the demo video showed that this "diesel" engine was spark ignited
. You would need a ring of diesel injectors for good fuel/air distribution. Getting the right fuel spray pattern and air swirl is feasible, but would take development.
The main point worth considering is that turbo charging offers a good way to improve power/weight of a conventional engine. A gas turbine can be seen as a big pistonless turbodiesel
, giving an idea of power/weight possibilities. The limit to this boost is normally combustion initiation, with various alternate methods currently being investigated.
I suspect that a range of more compact turbodiesels, with improved crank mechanisms and combustion mechanisms will now start to appear. The main limitation for more conventional designs is always cost and durability, and i'm afraid a demo with a load of compressed air
doesn't do it for me...
Mart
. My VW 4 cyl diesel averaging 70mph over 500 miles gets roughly 50mpg. An engine with an equivalent of 32 pistons will offer greater surface area (about 4 times) for the same displacement to loose heat. If 20% heat loss is through the radiator of my VW, then a very quick calc indictes that this would go up to about 50% heat loss - so 50mpg becomes approx 31.25mpg...Large displacement iron block 6-cyl truck engines are not a fair comparison for mass either, since they are designed for 15'000 cost effective hours of extreme conditions before overhaul. A better package, especially for small displacement, would be two large diam pistons per arm (or whatever it is called). That crank mech looks relatively complicated too, so the only weight saving i see is in the block/head casting mass (worth considering though).
The main problem with this type of design is always emissions. Like a uniflow scavenge 2-stroke, you need to keep the rings oiled. This means that there is a steady leakage of oil from the exhaust valve. 4-stroke poppet valves are a compromise, but they do work.
I notice the demo video showed that this "diesel" engine was spark ignited
. You would need a ring of diesel injectors for good fuel/air distribution. Getting the right fuel spray pattern and air swirl is feasible, but would take development.The main point worth considering is that turbo charging offers a good way to improve power/weight of a conventional engine. A gas turbine can be seen as a big pistonless turbodiesel
, giving an idea of power/weight possibilities. The limit to this boost is normally combustion initiation, with various alternate methods currently being investigated.I suspect that a range of more compact turbodiesels, with improved crank mechanisms and combustion mechanisms will now start to appear. The main limitation for more conventional designs is always cost and durability, and i'm afraid a demo with a load of compressed air
doesn't do it for me...Mart
Last edited by Graviman; 16th May 2006 at 11:30. Reason: Now watched videos....
OZ diesel?
At Avalon Airshow 2005, an Australian aircraft diesel was on display. I believe it was aimed at R22 and R44 size helicopters. The four cyclinder produced about the same as the Beta II and six cylinder was in the R44 power class.
Although slightly heavier, it uses less fuel. As a turbocharged engine it can hold its puff to 15,000 ft and then fades away to 70% power at 30,000 ft.
Real Robbie sky up there!
Diesels have better fuel flow, cheaper fuel, cost more to buy, a little heavier, need less fuel on board, cheaper maintenance and maybe better emmissions?
About $35 per hour less over 2,200 hours in an R22 is suggested. Not a great deal, but if fuel prices go the way they are??
I am not sure if it is going into production, but their website has some comparions to pistons, a good topic for a rainy day crewroom discussion - at least you can get a feel for a diesel versas piston versas turbine.
Maybe Frank's R66 or such may have one of these smelly rubber bands?
Trouble is new engines need years of regulator paper work and testing to get certified. Our CASA now undergoing another reorganisation, move of HQ and spilling of many positions, may not have the HP to carry any serious downunder development work.
After all we gave the Victa Air Trainer to NZ and canned the Nomad which with more work could have been a saleable aircraft.
Today, it was announced we may bin the Navy Seasprite project - it has only cost us US$750 so far.
Any other diesel versas petrol power units ideas.
Although slightly heavier, it uses less fuel. As a turbocharged engine it can hold its puff to 15,000 ft and then fades away to 70% power at 30,000 ft.
Real Robbie sky up there!
Diesels have better fuel flow, cheaper fuel, cost more to buy, a little heavier, need less fuel on board, cheaper maintenance and maybe better emmissions?
About $35 per hour less over 2,200 hours in an R22 is suggested. Not a great deal, but if fuel prices go the way they are??
I am not sure if it is going into production, but their website has some comparions to pistons, a good topic for a rainy day crewroom discussion - at least you can get a feel for a diesel versas piston versas turbine.
Maybe Frank's R66 or such may have one of these smelly rubber bands?
Trouble is new engines need years of regulator paper work and testing to get certified. Our CASA now undergoing another reorganisation, move of HQ and spilling of many positions, may not have the HP to carry any serious downunder development work.
After all we gave the Victa Air Trainer to NZ and canned the Nomad which with more work could have been a saleable aircraft.
Today, it was announced we may bin the Navy Seasprite project - it has only cost us US$750 so far.
Any other diesel versas petrol power units ideas.
PM for website
Forgot to mention if you want the diesel website, PM me.
As mentioned before, I am not sure if it will make production; however, the test data is interesting to you rev heads.
It uses Jet A1 also, a lighter fuel overall.
As mentioned before, I am not sure if it will make production; however, the test data is interesting to you rev heads.
It uses Jet A1 also, a lighter fuel overall.
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3,000hp from 150lb and 150mpg ? Nice goal, but without any demonstrated hot stream hardware it's difficult to separate this from any of the other 'miracle' claims made for toroidal, quasiturbine and nutating engines made over the years. (I like the message in the forum section from the individual who 'doesn't understand how the concept works' but still wants to put money behind the idea. Aah, my favorite type of investor...!)
If Robinson do go diesel, you'd have to think they'll use one of the better-known designs (SMA, Thielert, DeltaHawk, Mistral, etc.). Though that 'joke' R66 website circulated recently showed an Arrius. 
A$950M on second-hand SH-2s. Ouch ! 
I/C
Originally Posted by robsrich
Maybe Frank's R66 or such may have one of these smelly rubber bands?
Originally Posted by robsrich
Today, it was announced we may bin the Navy Seasprite project - it has only cost us US$750 so far
I/C
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Originally Posted by Robsrich
At Avalon Airshow 2005, an Australian aircraft diesel was on display. I believe it was aimed at R22 and R44 size helicopters. The four cyclinder produced about the same as the Beta II and six cylinder was in the R44 power class.
Mention of Deltahawk at Avalon ; Avalon Deltahawk site
Mart
Last edited by Graviman; 20th May 2006 at 23:51.
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We just need to re-engineer this http://www.bath.ac.uk/~ccsshb/12cyl/ for aeronautical use. Fuel consumption at maximum economy is 0.260 lbs/hp/hour.
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Have a look at www.revetec.com
These guys have modified the bottom part of the engine, the crankshaft area, & it produces more power, uses less fuel than normal engines. They hope to eventually get it into aircraft, so hopefully it proves successful in cars first.
These guys have modified the bottom part of the engine, the crankshaft area, & it produces more power, uses less fuel than normal engines. They hope to eventually get it into aircraft, so hopefully it proves successful in cars first.
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It's an interesting idea, Nigel - but i don't buy it!
The cam mechanism is extremely large compared to the piston - bad for packaging.
The resulting torque curve can be optimised, but sinusoidal motion is generally best for 4-strokes.
Apart from removing piston side forces (which is good), there is no reason efficiency would be any different from ANY engine with a 3:1 mechanical gearing.
For heavy duty diesels the last thing you want to do is to force the gearbox to handle higher torques! This is why hub reduction is so favoured, to keep diff sizes down.
Finally for a helicopter weight is king, and i just don't see any real reason that they can make any weight reduction claims. The ideal is that you put the reduction gear as close to the rotors as you can. I suspect time will put this into the interesting distraction category...
Mart
The cam mechanism is extremely large compared to the piston - bad for packaging.
The resulting torque curve can be optimised, but sinusoidal motion is generally best for 4-strokes.
Apart from removing piston side forces (which is good), there is no reason efficiency would be any different from ANY engine with a 3:1 mechanical gearing.
For heavy duty diesels the last thing you want to do is to force the gearbox to handle higher torques! This is why hub reduction is so favoured, to keep diff sizes down.
Finally for a helicopter weight is king, and i just don't see any real reason that they can make any weight reduction claims. The ideal is that you put the reduction gear as close to the rotors as you can. I suspect time will put this into the interesting distraction category...
Mart
Last edited by Graviman; 23rd May 2006 at 11:28.
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Grav, you may have missed the finer points of the design - the "trilobate" cams allow the power stroke to be refined, with a tunable mechanical advantage via the shape of the cam. If you were into bicycling in the late '70s, you may remember the "biopace" chainring, designed to match the load on the cyclist's leg to the amount of leverage available at each point of the pedal cycle. The cams in the Revetec do a similar thing. They also seperate the piston cycle rate from the crankshaft revs, meaning that you get three power strokes per crankshaft revolution.
I have no idea whether this recip will go anywhere, but it is definitely more of a change than just a gear ratio - if anything, it's a cross between a conventional recip and the Dynacam engine.
I have no idea whether this recip will go anywhere, but it is definitely more of a change than just a gear ratio - if anything, it's a cross between a conventional recip and the Dynacam engine.
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My tecnical engine knowledge is pretty close to zero but I have met the inventor & he is very happy with the development progress. As you can see, the engine is off to India & if successful, might go into a million or so local cars.
I think the plans for an aviation engine is still down the track a bit.
Shares are available in his company!!
I think the plans for an aviation engine is still down the track a bit.
Shares are available in his company!!
G'day all,
Until recently, I was the SMA Field Support Rep. (Asia-Pacific Region) for their deisel concept engines running on Jet-A. The engine is a 4cyl turbo-charged direct injection 230HP engine, using approx. 36L/pHr, compared to a similar Horsepower engine using 54-60L/pHr. Maintenace costs were just under a half, and maintenance intervals were twice as long. The technology is there and available, with excellent benefits!! Its just that not too many people are willing to fork out the initial fitting and purchasing of the Kit costs, which can equate to approx. 3 times the basic overhaul cost of standard old engine.
For 2 years I had expressed the interest of a helicopter operator to SMA in France, that an STC should be made available for helicopters such as the 300Cb & R44. Unfortunately, the powers of above chose not to follow this path for several reasons, BUT that is not to say that it will not happen in the future....
Please PM me if you have any serious questions, or just post them here.
Cheers, KP
Until recently, I was the SMA Field Support Rep. (Asia-Pacific Region) for their deisel concept engines running on Jet-A. The engine is a 4cyl turbo-charged direct injection 230HP engine, using approx. 36L/pHr, compared to a similar Horsepower engine using 54-60L/pHr. Maintenace costs were just under a half, and maintenance intervals were twice as long. The technology is there and available, with excellent benefits!! Its just that not too many people are willing to fork out the initial fitting and purchasing of the Kit costs, which can equate to approx. 3 times the basic overhaul cost of standard old engine.
For 2 years I had expressed the interest of a helicopter operator to SMA in France, that an STC should be made available for helicopters such as the 300Cb & R44. Unfortunately, the powers of above chose not to follow this path for several reasons, BUT that is not to say that it will not happen in the future....
Please PM me if you have any serious questions, or just post them here.
Cheers, KP
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Petrol Heads
Would it be worthwhile suggesting a merge of 'the wankel' and 'the futue of combustion engines'threads.
After all most of us are petrol heads.
The MYT, hmmm, compression ratio 25-1. Gyros – Radios - long term and short term memory – and all sorts of periodics?? - I shudder.
From the archives of the grey matter I dredged the below, looks like Sarich cashed the baby and cleared with the bathwater.
http://www.smh.com.au/articles/2004/05/03/1083436541894.html
And then on the same google I found another OZ contraption, a hybrid, a rather interesting turnout??
http://www.kec.com.au/articles.html
After all most of us are petrol heads.
The MYT, hmmm, compression ratio 25-1. Gyros – Radios - long term and short term memory – and all sorts of periodics?? - I shudder.
From the archives of the grey matter I dredged the below, looks like Sarich cashed the baby and cleared with the bathwater.
http://www.smh.com.au/articles/2004/05/03/1083436541894.html
And then on the same google I found another OZ contraption, a hybrid, a rather interesting turnout??
http://www.kec.com.au/articles.html
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Originally Posted by Flingwing
If you were into bicycling in the late '70s, you may remember the "biopace" chainring, designed to match the load on the cyclist's leg to the amount of leverage available at each point of the pedal cycle.
Seriously though, i've seen a lot of ideas based around the idea of altering the pistion motion for improved efficiency. Sinusoidal just gives the gases the best chance of exchange. I can see why a dwell at the base of a 2-stroke might be considered usefull, but again why not just increase the stroke and avoid the higher order balancing issues.
I'm not a great fan of the crank mechanism, but it's simplicity and compactness are pretty hard to beat. Given the choice i prefer the epicycloidal mechanisms associated with rotaries, but there are combustion issues here.
See other engine thread
- perhaps a merging is in order...Mart
