Moller Invents Supercharged Rotary Engine
 

This looks like a promising development for the rotary! The article mentions how this new design improvment obtains a better than 12% improvment in MPG over the Rennisis. With furthur development they expect anothe 25% fuel reduction :Eyecrazy:

http://www.nextenergynews.com/news1/...s5.16.08b.html

Flying rotary car anyone?

Nice find!

holy shit, that is freakin awsome news!!! Man thats exciting

I'd like to see a drawing of the compound set up. Or better yet maybe RG could stop by and let us know if this is something he had ever looked at :)

great news for the rotary

bad news for mazuda

look at it again.

"......12% below that of the new Mazda Renesis rotary engine."

the way i see the quote is "Moller International's non-compounded Rotapower rotary engine has already demonstrated a fuel consumption 12% below that of the new Mazda Renesis rotary engine." Meaning it already consumes 12% less fuel.

The compound design will imporve that by ANOTHER 25%!

it seems to be its probably 25% more fuel efficient because it makes 25+% less power...

they have a 530cc singe rotor and it makes 35-50hp. Make it a triple rotor and you have more siplacement then the Renesis and lots less power... http://www.freedom-motors.com/

fuel consumption 12% below those of renesis, tat is a good thing rasp =p

It looks like you are referencing an already established wankle based scaled down rotary engine. I didn't see anything about the compound-rotary design. That is the new twist i'd like to see more about.

I've thought about what they are doing and quite frankly the way they have gone about it is quite creative! What they are doing is called turbocompounding and it is something that has been used for a long time to increase efficiency going back to WWII fighters.

Study this website and the links on it. This is a page from an aircraft rotary engine website. Tracy Cook sees the future of rotary efficiency as being turbo compounding and he shares some of his (overly complex) ideas.

http://www.rotaryeng.net/turbo-compound.html

Now once you've gone over that and studied how it works, imagine instead of using a turbosupercharger as in those diagrams, you instead replaced it with a rotor. This rotor just happens to be the other one. You make it larger. It brings in air and compresses it but instead of getting ignited and sent further around, just imagine a port located where the trailing spark plug is. This sends the now compressed air out of this rotor after only having travelled half of the rotational distance of the rotor and moves this air to the inlet of the other smaller rotor. Now it's basically boosted air. It gets compressed in this rotor, ignited and sent back around just as all other rotaries do now. The difference being that when it gets to the exhaust ports, the exhaust now gets sent back to the other rotor and enters in somewhere around below where a leading spark plug would be. Now it goes through further expansion (since it has picked up heat energy), and recovers some of this energy by pushing on the rotor before getting sent out of the engine. Because some of this energy was recovered and returned to the crank, it is more efficient than if the energy had merely been sent out the tailpipe. The larger compressing rotor would not have dished rotor faces so compression could be taken up quite high as a result.

I like it! The key of course is not to think of the engine as a 2 rotor that makes 2/3 the power but rather a 1 rotor that makes 2/3 the horsepower of 2 with greater efficiency that is quieter and also has a large wankel supercharger attached to the front of it!

Thanks RG! That was a great explanation. I can picture it perfecly now :)

what about power output.
________
Washington Dispensaries

what a bout a 3 rotor design .. the 1st rotor compresses air for the other 2? is this possible?

wait...so then if you added a turbo...

youd give yourself an stroke trying to figure the math out...haa

if it's 96% quieter, I'm going to need a 35" ID catless midpipe to make up for it.

Thanks Fred!!

I've been searching for this snippet for a LONG TIME!!

"The power in the Mazda Wankel rotary engine exhaust has been talking to us for 30 years.
It has been saying. "Hook me to turbine, hook me to a turbine, hook me to
a turbine." Anybody that has been around a Mazda rotary powered race car
without a muffler can understand the tremendous kinetic energy in the exhaust.
I have a race car driver friend by the name of John Morton who claims he
has permanent hearing damage from driving rotary powered race cars.

It was not until I read that SAE paper on the R3350 TC that I could put
a number on it. It then hit me like a supersonic shock wave. Yes of
course it has plenty of kinetic energy in the exhaust.

Now comes the time to harness all those super sonic horses.

Think of the Wankel rotary as an ideal gas generator for a turbine
engine. A marriage made in heaven."

I had lost it a year ago...much like my mind...

Of course it's quieter. The compound turbocharger/rotor is absorbing lots of energy. Sound is a form of energy. A turbo quiets an engine down considerably and sound can actually pass straight through it quite easily. With this arrangement, the sound of the exhaust leaving the power rotor is never opened to the outside world. It is always hidden somehow behind the closed ports of another rotor's chamber. I'd be willing to be it would require very little muffling. However I'm also pretty sure that enough heat is lost in the process that cat lightoff would be pretty difficult to do.

If you reread the article you can see that Moller has already passed all of california's emmission standards with a completly catless unit. That is pretty cool shit!

subscribed

there is no way anyone is going to convince me that using exhaust gases and engine torque to spin a dead rotor (which has lots of rotational inertia, lots of friction, and a poor design for this job) and use it as a compressor is any more efficient then sending the exhaust gases to a dedicated turbo which is low on friction, low on rotational inertia, has blades designed to compress air efficiently, and is not run off the engine....

someone might as well ask moller how his "skycar" has all this engineering and after 10 years now hasn't done anything more then lift of the ground a few feet... its worse then John Delorean - at least he made a car that actually could drive

good point rotor , although the claims that emissions, noise and fuel consumption are reduced is enough to make it worth seeing how far this will go .

so basically its just like a turbocharged rotary engine, however, they use a rotor as a semi-turbo instead eh? cool ^^

you might want to look up what the rotary was originally used for..

thats pretty cool. id love to see new designs of the rotary in the near future

surprised RG didn't mention the Rolls Royce Diesel engine which used the Larger rotor to compress the mixture which was then passed to the smaller rotor and compressed further before ignition. Same idea- the larger rotor acts as a supercharger for the smaller. You could probably call it an Atkinson cycle rotary and get away with it:)



https://www.rx8club.com/attachment.p...1&d=1211091531

what book is that^^^ ?

Guaya Guaya Caravana de RX8
 

um what? how bout a translation

water pump?

Supercharger.

It's not an atkinson cycle. If it were, there wouldn't be a second rotor. There'd just be a combustion chamber where nothing gets further compressed. However we have an actual 4 cycle engine in there as well which is what the second rotor is. Calling this an Atkinson cycle would mean we would have to call every single turbocharged engine out there an atkinson cycle. That's not even remotely accurate.

You misunderstand what the intention of turbo compounding really is all about. It's not about boosting power through the use of a turbocharger. Everyone assumes that a turbo is only good for adding power. What this is intended to be used for isn't so much a power adder but rather an efficiency booster. There is more to it than simple boost. The goal is only a small power increase through the use of boost. It is also intended to capture some wasted energy and send it back to the crank which it does.

While it may appear that spinning another rotor is an awful lot of energy, it probably isn't as bad as you think it is. Let's compare it to another crank driven device, a centrifugal supercharger. These things are HUMONGOUS parasitic draws on an engine. Why anyone in their right mind would ever want to strap one on their engine is beyond me as it's a product that is a dead end with little real world potential. While another rotor is a parasitic draw, it is compressing air and sending it to another rotor. This means boost which means more power than normal to overcome this rotor. Then some energy is being reabsorbed back by this rotor and sent back to the crank. The result should be a power level that is noticably greater than a 1 rotor on it's own but with lower fuel consumption than the 1 rotor on it's own. Not to mention the noise reduction. That's a win/win design. It's not about max power. The great power wars are coming to an end and it's about time. It's time to shift to efficiency because at the end of the day, that's what is going to sell the most to average buyers.

Ignore the use of a rotor as only a supercharger. That's only part of it. I'd like to see this idea pursued more or rather at all by Mazda which I doubt they'll do.

subscribing

Sorry for that. I was thinking Miller cycle actually sinc eit uses a supercharger for increased efficiency much like this rotor idea uses its 1st rotor. However i wasnt taking into account the unequal relationship between the power and exhaust stroke of the atkinson cycle.. my bad

It was admittedly fairly easy to see it that way. It's not quite a jet engine yet!

you mean 16X-based, turbo compounded, side port, direct injected, quad rotor, and a single variable geometry turbo...

pfft...been there...done that...went back to hamster wheels...heh...

......*Mind Explodes*

This is a very good read. I can't wait to see how it goes further.

I just shot an email over to info@moller.com asking anyone of them to come over and join the dicussion. I'm not sure they will but hey, it can't hurt :)

something like this?

http://www.rotaryeng.net/Turbo-compound2-3D.jpg

i kid...

A response from Moller
 

Hey guys, the General Manager just shot back a reply to my e-mail earlier today :)

Thanks, Brian. I will ask Dr. Moller to take a look. He typically does not personally talk on-line, but he may be able to address some specific questions for you.

We are a bit reluctant to show the porting arrangements until the patents are approved but most of your commenters seemed to get the idea pretty well already. If Dr. Moller can reveal some of the technical details without risk I am certain he would be pleased to share it with your readers.

As for the comment on the Skycar not being able to do much except brief vertical take offs and landings I'd like to remind this person that most planes don't do this at all...and we did this with our air-cooled 70 hp Rotapower (rotary) engines versus the 140 hp (twin-rotor) engines we have available now. Over the course of the volantor's development path, Dr. Moller has built and flown 5 different prototype aircraft, each with progressively more capabilities. The latest, commonly known as the Skycar, is a four-passenger, 2,400 lbs AUW aircraft capable of helicopter-like VTOL and yet is anticipated to be nearly three times faster than a helicopter with a 350 mph dash speed and 230+ mph cruise speed @ 20+ mpg. The schedule has, as one would expect for a totally new type of aircraft, slipped a number of times. It is a very costly project and we have run out of funding numerous times, but unlike the other dozen or so companies that started on a "personal" VTOL some 20 years ago, we are still in business and still moving forward. With the exception of Boeing, we are the only ones left that help create the preliminary FAA "Powered Lift - Normal" classification, and I don't see Boeing providing an affordable private aircraft anytime soon. So we are it for now and absolutely dedicated to making the Rotapower rotary engines a success in this and in other non-aviation products.

Regards,

Bruce *****
General Manager
Moller International
www.moller.com

Discuss :lol:

For the record....
I'm an engineer at a combined cycle powerplant - which means we take waste heat from combustion turbines and use it to fuel a steam cycle... so i know the concepts of reusing waste heat.

The fact is you have a finite amount of energy to use with compounding or turbocharging. Either way your reusing the energy to increase efficiency by reducing the losses in the combustion process during the intake stroke and taking a minimal hit in the exhaust stroke. How well you utilize the energy comes down to how efficient the process is that you use to convert it... and i do not see a dead rotor approaching the 75-78% efficiency of a turbo.

the problem is turbo does not increase fuel efficiency, because all a turbo does is force more air into the combustion chamber, combined with increase injection of fuel to increase the power output per volume.

Think of the 2nd rotor as a Hot side of a turbo with no cool side, the hot exhaust just spins the "turbine" which help spins the shaft mechanically. there is no power boost, just attempt to suck all the power of the 1st combustion cycle by forcing the exhaust to push 2 rotors.. i am sure there is a bypass for start up when exhaust velocity/energy is low, but when it's higher, it can harnass the exhaust.

It seems to me that feeding the exhaust stroke into the face of a rotor would capture more (nearly all) energy from that exhaust than simply blowing it past the face of a fan where only a portion of that gass makes physical contact with the blades.

If noise reduction in this system directly corelates with the amount of energy harnessed I wouldn't be surprised at all to see this surpass turbos in efficency. Keep in mind w/o any combustion taking place on this rotors face it can be made out of much lighter material than the rotor in the combustion chamber.

Wonder how it is lubricated, without pushing unburned oil out the ports (unless it uses side ports?)...or if the exhaust gas temps would be enough to burn it.

Also, I wonder what the long term effects would be on the rotor from soot build up from the exhaust.

I know it is a new design and they are working on it, but wonder how it will end up work out. Awesome to hear more development outside of mazda on the rotary.

the compression rotor can be made lighter and from a material which will not need to withstand the combustion cycle...

then you cram that into the smaller rotor which could be made from a more expensive material to withstand higher temps/stress...

materials engineering in this case will be a huge factor for efficiency and design i would imagine...

Some turbos like the Greddy kit can only feed air on the current Renesis up to 7-7.5K rpm? Given rotaries naturally have higher rpms, in order to have a turbo feed air throughout the complete rev range, wouldn't the turbo have to be larger? Versus on a regular engine of the same displcement? So wouldn't a larger turbo be less efficient as far as mpg go? Or if they'd use a smaller turbo on the 16x with a lower redline than the current 13b, would it be more efficient?

I'm knew to this, my head hurts......lol.

In this case, the front rotor (supercharger) is a positive displacement unit.

Does anyone have a flow map of a rotary based supercharger? What kind of efficiency range would it have?

LOL! Reminds me of how I convinced my wife (a tree hugger) that a turbocharger for my Miata was actually a green device since it recycled otherwise wasted exhaust heat energy. OK, maybe it wasn't turbo compounding, but the point is it worked.