Why are Mazda persisting with the Rotary Wankel engine?
Discussion
Super Slo Mo said:
RayTay said:
Steam turbines are still operating in power stations. Hopefully gas turbines have tipped over in the running costs. Then there will be widespread adoption.
I realise it's getting off topic somewhat, but it sounds like you think steam turbines are old hat?I would like to see what alternatives there are, to generate the level of power required at any of the major power stations, that don't use steam. And that come even close to a steam turbine in terms of overall efficiency.
That aside, without a steam turbine, a nuclear power station is pretty useless, unless there's something else you can do with all the heat generated.
No idea why they're persisting but glad they are all the same.
787b is reason enough in my book.
787b is reason enough in my book.
- volume*
RayTay said:
Super Slo Mo, I do not think steam turbines are old hat at all. They are very efficient at niche applications, ideal for power generation. Water turbines likewise. In the past decade or so there has been quite a bit of R&D in small steam engines. Using external continuous combustion is far cleaner in emissions than a series of dirty explosions. But everything is aiming for electric traction drive and steam seems to have been put on the back burner. It is what range-extender (genset) will win: rotary, gas turbine, free piston, Stirling or even steam.
Ok, my misinterpretation. Sorry. Back in my Uni days we had a field trip to Rugeley Power Station. I still have fond (I'm a geek) memories of standing by the huge 500MW steam turbines as they were running. They were quite loud in operation, even with hearing protection. They had a couple of 25-30MW gas turbines on standby too, for peak demand etc, although these were relatively small in size compared to the steam turbines.
Super Slo Mo said:
Ok, my misinterpretation. Sorry.
Back in my Uni days we had a field trip to Rugeley Power Station. I still have fond (I'm a geek) memories of standing by the huge 500MW steam turbines as they were running. They were quite loud in operation, even with hearing protection. They had a couple of 25-30MW gas turbines on standby too, for peak demand etc, although these were relatively small in size compared to the steam turbines.
I have been to few power stations many years ago when involved in control equipment. Very impressive places. I recall a coal fired station at Grays on the Thames with its own coal pier with coastal type of coal ships coming in from Poland. The place was filthy inside. Not a nice experience. You will find that most of the electricity all around us is produced by steam. Back in my Uni days we had a field trip to Rugeley Power Station. I still have fond (I'm a geek) memories of standing by the huge 500MW steam turbines as they were running. They were quite loud in operation, even with hearing protection. They had a couple of 25-30MW gas turbines on standby too, for peak demand etc, although these were relatively small in size compared to the steam turbines.
When Thatcher had her war against the coal miners she used North Sea Oil and gas as her weapon. Coal was replaced by gas to raise the steam, and a number of diesel generators in stations sprang up. The diesels were mainly for peak use. The coal stations are moving over to cleaner and more sustainable biomass fuel. Immingham and Newcastle on the east coast for biomass from the Nordic countries and the large unloading facilities at Liverpool from North America.The CV of biomass is far less than coal, so a train load of coal with be the equivalent of about four trains of biomass. This, with Liverpool's container expansion and opening of the Northwest Passage is why Liverpool is pissed off that a HS2 line is not being planned to run into the city. HMG never thought of it and is reluctant to admit it was wrong.
Interestingly, the Scandinavians have small local power stations and use the waste heat for residential heating. They use some gas turbines in them. The overall efficiency is over 90%.
Edited by RayTay on Friday 7th December 12:10
e21Mark said:
No idea why they're persisting but glad they are all the same.
787b is reason enough in my book.
*volume*
https://www.youtube.com/watch?v=OjwwV20iZYE
That engine is phenomenal. At Le Mans it even used less fuel than the competition. So much for thirsty rotaries, and this was 25 years ago. After a post race strip down the engine was seen to be capable of running another 24 hrs race. 787b is reason enough in my book.
*volume*
https://www.youtube.com/watch?v=OjwwV20iZYE
Mazda 787B
https://en.wikipedia.org/wiki/Mazda_787B
The R26B engine:
https://en.wikipedia.org/wiki/Mazda_wankel_engine
Many races ban rotary engines, otherwise they would beat piston engines each time. I read that pressure from piston engine companies, who did not make rotaries and had little knowledge of them, was the motive to ban them, fearing reduced sales.
Edited by RayTay on Thursday 11th August 11:15
The American M1 Abrams tank uses an auxiliary rotary engine power unit. All power came from the main turbine and consumed masses of fuel when the tank was stopped. The auxiliary rotary genny may be used when the tank is stopped to provide a-c/heating and all electrical power when the main engines are off. The turret is operated by the rotary as well. So the tank can be 'hull down' with the engine off and turn the turret & gun.
The rotary engine may be used even when the main turbine is running and the tank is moving. The rotary engine genny was developed by the TARDEC U.S. Army lab. It has a high power density of 330cc modified to operate with various fuels such as, high octane military grade jet fuel. The entire fleet of Abrams tanks were retrofitted with the rotary auxiliary units. It saves 14% in overall fuel consumption. The rotary is inside the tanks reactive armour shield, so if disabled the tank has power and the RPG's will bounce off. The small size, high power output for its size and smoothness were advantages which led to the rotary being chosen. I believe it is made by PAT. Things are moving for the Rotary. Its attributes are being recognised.
A new diesel engine is being developed for the tank to give a smaller heat signature, but the rotary auxiliary is being kept.
The rotary engine may be used even when the main turbine is running and the tank is moving. The rotary engine genny was developed by the TARDEC U.S. Army lab. It has a high power density of 330cc modified to operate with various fuels such as, high octane military grade jet fuel. The entire fleet of Abrams tanks were retrofitted with the rotary auxiliary units. It saves 14% in overall fuel consumption. The rotary is inside the tanks reactive armour shield, so if disabled the tank has power and the RPG's will bounce off. The small size, high power output for its size and smoothness were advantages which led to the rotary being chosen. I believe it is made by PAT. Things are moving for the Rotary. Its attributes are being recognised.
A new diesel engine is being developed for the tank to give a smaller heat signature, but the rotary auxiliary is being kept.
Edited by RayTay on Saturday 17th September 08:52
Mazda has approved the Rotary sports car to be introduced in 2020, the 100th anniversary of Mazda. It is no longer a concept but a goer. The car is to have direct drive via a transmission.
http://www.motoring.com.au/mazda-rx-9-locked-in-10...
"Mazda’s board of directors has formally approved the design, engineering and production of the company’s long-awaited successor to the RX-7 and RX-8 rotary coupes, according to Japan’s Holiday Auto magazine which has also produced these new renderings."
"Expected to be called the RX-9 — a trademark Mazda has registered — the born-again performance coupe is not due on sale globally until January 2020, when it will be the centrepiece of Mazda’s centenary celebrations."
"It’s speculated that the Mazda sports car will combine turbocharging and diesel-style HCCI compression ignition in a world-first application, made all the more significant by applying the advanced fuel-delivery and ignition technology to a rotary engine."
http://www.motoring.com.au/mazda-rx-9-locked-in-10...
"Mazda’s board of directors has formally approved the design, engineering and production of the company’s long-awaited successor to the RX-7 and RX-8 rotary coupes, according to Japan’s Holiday Auto magazine which has also produced these new renderings."
"Expected to be called the RX-9 — a trademark Mazda has registered — the born-again performance coupe is not due on sale globally until January 2020, when it will be the centrepiece of Mazda’s centenary celebrations."
"It’s speculated that the Mazda sports car will combine turbocharging and diesel-style HCCI compression ignition in a world-first application, made all the more significant by applying the advanced fuel-delivery and ignition technology to a rotary engine."
Edited by RayTay on Monday 19th September 10:36
Awesome news! 
Looks like it's going to be much more akin to the RX-7 than the RX-8 which is good and bad, good because while the RX-8 was a great car it was also massively compromised by being a 4 door 2+2. Bad because the RX-7 was always a damn sight more expensive than the RX-8 and I might not be able to afford one!
Looks like it's going to be much more akin to the RX-7 than the RX-8 which is good and bad, good because while the RX-8 was a great car it was also massively compromised by being a 4 door 2+2. Bad because the RX-7 was always a damn sight more expensive than the RX-8 and I might not be able to afford one!
Fastdruid said:
Awesome news!
Looks like it's going to be much more akin to the RX-7 than the RX-8 which is good and bad, good because while the RX-8 was a great car it was also massively compromised by being a 4 door 2+2. Bad because the RX-7 was always a damn sight more expensive than the RX-8 and I might not be able to afford one!
I hope it ends up looking like this...Looks like it's going to be much more akin to the RX-7 than the RX-8 which is good and bad, good because while the RX-8 was a great car it was also massively compromised by being a 4 door 2+2. Bad because the RX-7 was always a damn sight more expensive than the RX-8 and I might not be able to afford one!
Mazda lodged new rotary patents:
http://www.businessinsider.com/mazda-files-new-pat...
http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PT...
They are to put the engine upside down. The turbo(s) on the top of the engine and the intake under.
"When the rotary piston engine is seen along the output shaft, the intake port is formed in a lower part of the rotary piston engine body and the exhaust port is formed in an upper part of the rotary piston engine body. The intake passage is disposed on one side of the rotary piston engine body and the exhaust passage is disposed above the rotary piston engine body."
http://www.businessinsider.com/mazda-files-new-pat...
http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PT...
They are to put the engine upside down. The turbo(s) on the top of the engine and the intake under.
"When the rotary piston engine is seen along the output shaft, the intake port is formed in a lower part of the rotary piston engine body and the exhaust port is formed in an upper part of the rotary piston engine body. The intake passage is disposed on one side of the rotary piston engine body and the exhaust passage is disposed above the rotary piston engine body."
Edited by RayTay on Monday 19th September 11:22
RayTay said:
Mazda lodged new rotary patents:
http://www.businessinsider.com/mazda-files-new-pat...
http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PT...
They are to put the engine upside down. The turbo(s) on the top of the engine and the intake under.
"When the rotary piston engine is seen along the output shaft, the intake port is formed in a lower part of the rotary piston engine body and the exhaust port is formed in an upper part of the rotary piston engine body. The intake passage is disposed on one side of the rotary piston engine body and the exhaust passage is disposed above the rotary piston engine body."
That makes a lot of sense when considering under bonnet temperatures. With the inlet above the exhaust the heat soak when stopped on early rotaries was enough to boil the fuel in the carburettors and make them very hard to start. Injection has helped but it still makes a lot of sense to use physics to help keep the heat away from the fuel. http://www.businessinsider.com/mazda-files-new-pat...
http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PT...
They are to put the engine upside down. The turbo(s) on the top of the engine and the intake under.
"When the rotary piston engine is seen along the output shaft, the intake port is formed in a lower part of the rotary piston engine body and the exhaust port is formed in an upper part of the rotary piston engine body. The intake passage is disposed on one side of the rotary piston engine body and the exhaust passage is disposed above the rotary piston engine body."
Edited by RayTay on Monday 19th September 11:22
Rotaries are frequently used in aero applications due to their failure mode. When a tip seal fails the engine will continue to run fairly happily until its shut down where it will refuse to restart. A piston engine in a similar situation will often stop running as it will foul plugs.
Edited by lostkiwi on Monday 19th September 15:53
RayTay said:
Mazda lodged new rotary patents:
http://www.businessinsider.com/mazda-files-new-pat...
http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PT...
They are to put the engine upside down. The turbo(s) on the top of the engine and the intake under.
"When the rotary piston engine is seen along the output shaft, the intake port is formed in a lower part of the rotary piston engine body and the exhaust port is formed in an upper part of the rotary piston engine body. The intake passage is disposed on one side of the rotary piston engine body and the exhaust passage is disposed above the rotary piston engine body."
Interesting developments, as a fan of mazdas rotary (no matter what the shortcomings were), and an engineer, I am very interested to see how things further develop for this engine.http://www.businessinsider.com/mazda-files-new-pat...
http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PT...
They are to put the engine upside down. The turbo(s) on the top of the engine and the intake under.
"When the rotary piston engine is seen along the output shaft, the intake port is formed in a lower part of the rotary piston engine body and the exhaust port is formed in an upper part of the rotary piston engine body. The intake passage is disposed on one side of the rotary piston engine body and the exhaust passage is disposed above the rotary piston engine body."
Edited by RayTay on Monday 19th September 11:22
Having the exhaust as short as possible with the turbos on the top, right on the engine housing makes sense. And keeping the injection side cooler helps. I assume this is also to do with the HCCI ignition characteristics which Mazda are keen on implementing.
wiki, who got it right:
"wankel engines that operate within their original design parameters are almost immune to catastrophic failure. A wankel engine that loses compression, cooling or oil pressure will lose a large amount of power and fail over a short period of time. It will, however, usually continue to produce some power during that time, allowing for a safer landing when used in aircraft. Piston engines under the same circumstances are prone to seizing or breaking parts that almost certainly results in catastrophic failure of the engine and instant full loss of power. For this reason, wankel engines are very well suited to snowmobiles, which often take users into remote places where a failure could result in frostbite or death, and aircraft, where abrupt failure is likely to lead to a crash or forced landing in a remote place."
lostkiwi said:
Rotaries are frequently used in aero applications due to their failure mode. When a tip seal fails the engine will continue to run fairly happily until its shut down where it will refuse to restart. A piston engine in a similar situation will often stop running as it will foul plugs.
Yes, spot on....wiki, who got it right:
"wankel engines that operate within their original design parameters are almost immune to catastrophic failure. A wankel engine that loses compression, cooling or oil pressure will lose a large amount of power and fail over a short period of time. It will, however, usually continue to produce some power during that time, allowing for a safer landing when used in aircraft. Piston engines under the same circumstances are prone to seizing or breaking parts that almost certainly results in catastrophic failure of the engine and instant full loss of power. For this reason, wankel engines are very well suited to snowmobiles, which often take users into remote places where a failure could result in frostbite or death, and aircraft, where abrupt failure is likely to lead to a crash or forced landing in a remote place."
Edited by RayTay on Monday 19th September 14:49
Mazda R&D boss Kyoshi Fujiwara confirmed Mazda will incorporate HCCI in the new RX-Vision sports car rotary engine. The fuel/air mixture is compressed to the point of auto-ignition, as in a diesel engine. HCCI engines achieve extremely low levels of nitrogen oxide emissions without a catalytic converter.
Mazda claim they have solved emissions and fuel consumption problems in the new SkyActiv-R engine. They are also developing a small simple range-extender for series hybrids to be introduced after the RX-vision is launched
http://www.motoring.com.au/new-mazda-rx-secrets-re...
http://www.carsguide.com.au/car-news/mazda-skyacti...
https://etd.ohiolink.edu/!etd.send_file?accession=...
If all this is a success, then rotaries should dominate range-extenders.
Mazda claim they have solved emissions and fuel consumption problems in the new SkyActiv-R engine. They are also developing a small simple range-extender for series hybrids to be introduced after the RX-vision is launched
http://www.motoring.com.au/new-mazda-rx-secrets-re...
http://www.carsguide.com.au/car-news/mazda-skyacti...
https://etd.ohiolink.edu/!etd.send_file?accession=...
If all this is a success, then rotaries should dominate range-extenders.
No engine is sold yet with HCCI ignition. Mazda say they have cracked it as a part of their SkyActiv research, to introduce it into piston and rotary engines. HCCI works very well indeed with constant speed engine applications.
An explanation of HCCI:
https://www.youtube.com/watch?v=OVWZFdb_AGc
An explanation of HCCI:
https://www.youtube.com/watch?v=OVWZFdb_AGc
Edited by RayTay on Wednesday 21st September 17:08
AIE (UK) have done research and made advancements. David Garside was the man responsible. He developed the Norton rotary engines. They call it SPARCS. They found that idle stability and greater economy was obtained by using only one rotor in a multi rotor engine when idling.
Garside, developed three new patents this year: 1) SPARCS (Self-Pressurising-Air Rotor Cooling System), 2) Compact-SPARCS and 3) CREEV (Compound Rotary Engine for Electric Vehicles)
SPARCS and Compact-SPARCS provides imrpoved heat rejection and efficient thermal balancing in the engine This optimises lubrication. This results in reduced engine wear.
SPARCS uses a sealed rotor cooling circuit consisting of a circulating centrifugal fan and a heat exchanger to reject the heat. This is self-pressurised by capturing the blow-by past the rotor side gas seals from the working chambers, uses the exhaust gases from combustion to pressurise the fuel-air mixture.
CREEV is a ‘exhaust reactor’ that consumes unburnt exhaust products giving lower emissions and improved fuel efficiency.
http://www.aieuk.com/sparcs/
http://www.foxnews.com/auto/2016/09/19/cool-new-ro...
A Westfield car with a SPARCS engine:
https://www.youtube.com/watch?v=AQJsmbzlMM0
"AIE has devised a new variation on the rotary engine called the Self-Pressurised Air Rotor Cooling System or SPARCS. This uses exhaust gases from the combustion process to pressurise the fuel-air mixture, which allows higher levels of heat removal and improves the sealing of the engine, since there is a smaller variation of temperature across the engine; this improves efficiency and fuel consumption. The company has also designed an exhaust expander system that effectively extends the engine expansion stroke to recover lost energy, giving a net power gain of 20 per cent."
"The expander is effectively a second rotary engine attached to the exhaust port of the primary wankel. Rather than having the wankel reuleaux inside at two-lobed combustion chamber, it has an elliptical rotor with pointed ends inside a circular chamber that is forced around by the expanding exhaust gases."
"The entire hybrid engine, consisting of engine, expander and a connected 25kW alternator, is 400mm long and 270mm deep and weighs 45.5kg; the engine component is a 225cc system with 56 parts, producing 40hp. The expander makes the engine quieter, because the exhaust gases are near atmospheric pressure when they leave the engine, and improve emissions characteristics. This can be used in UAVs, REEVs, motorbikes and as marine propulsion."
http://www.theengineer.co.uk/issues/august-2014-on...
Garside, developed three new patents this year: 1) SPARCS (Self-Pressurising-Air Rotor Cooling System), 2) Compact-SPARCS and 3) CREEV (Compound Rotary Engine for Electric Vehicles)
SPARCS and Compact-SPARCS provides imrpoved heat rejection and efficient thermal balancing in the engine This optimises lubrication. This results in reduced engine wear.
SPARCS uses a sealed rotor cooling circuit consisting of a circulating centrifugal fan and a heat exchanger to reject the heat. This is self-pressurised by capturing the blow-by past the rotor side gas seals from the working chambers, uses the exhaust gases from combustion to pressurise the fuel-air mixture.
CREEV is a ‘exhaust reactor’ that consumes unburnt exhaust products giving lower emissions and improved fuel efficiency.
http://www.aieuk.com/sparcs/
http://www.foxnews.com/auto/2016/09/19/cool-new-ro...
A Westfield car with a SPARCS engine:
https://www.youtube.com/watch?v=AQJsmbzlMM0
"AIE has devised a new variation on the rotary engine called the Self-Pressurised Air Rotor Cooling System or SPARCS. This uses exhaust gases from the combustion process to pressurise the fuel-air mixture, which allows higher levels of heat removal and improves the sealing of the engine, since there is a smaller variation of temperature across the engine; this improves efficiency and fuel consumption. The company has also designed an exhaust expander system that effectively extends the engine expansion stroke to recover lost energy, giving a net power gain of 20 per cent."
"The expander is effectively a second rotary engine attached to the exhaust port of the primary wankel. Rather than having the wankel reuleaux inside at two-lobed combustion chamber, it has an elliptical rotor with pointed ends inside a circular chamber that is forced around by the expanding exhaust gases."
"The entire hybrid engine, consisting of engine, expander and a connected 25kW alternator, is 400mm long and 270mm deep and weighs 45.5kg; the engine component is a 225cc system with 56 parts, producing 40hp. The expander makes the engine quieter, because the exhaust gases are near atmospheric pressure when they leave the engine, and improve emissions characteristics. This can be used in UAVs, REEVs, motorbikes and as marine propulsion."
http://www.theengineer.co.uk/issues/august-2014-on...
Edited by RayTay on Thursday 6th October 11:31
"With this new high performance rotary engine occupying less than 50% of the engine area volume and boasting a 50% reduction in overall weight from a standard four-cylinder engine, the 650S lends itself perfectly to the weight reduction and low emission requirements of the automotive industry whilst still delivering an impressive 120bhp performance using less fuel.
http://www.aieuk.com/first-british-rotary-engine-s...
This is encouraging. Things are moving for the rotary engine.
http://www.aieuk.com/first-british-rotary-engine-s...
This is encouraging. Things are moving for the rotary engine.
Edited by RayTay on Friday 7th October 18:03
Not looking too good http://www.roadandtrack.com/new-cars/future-cars/n...
Still in development apparently, but unsure whether it'll make production. I personally think it will though
Still in development apparently, but unsure whether it'll make production. I personally think it will though
http://www.roadandtrack.com/new-cars/future-cars/n...
Mazda have dropped the RX-Vision direct drive rotary engine sports car. That all makes sense. The rotary as a range-extender is by far the best application for this engine. They need to have high production levels which sports cars will not give them.
"Mazda–like the rest of the automotive industry–has put priority on introducing hybrid and electric cars in the face of tightening emissions regulations. The company has entered a partnership with Toyota to develop electrified vehicles."
Toyota is doing research on a free piston linear generator for hybrids. About 16 organisation around the world are doing so, and have been for over 20 years, and no one has perfected it yet.
https://en.wikipedia.org/wiki/Free-piston_linear_g...
The rotary looks the best bet for a small range extender engine. When on a constant speed & load the efficiency is better than piston engines.
"If we were to restart production of the rotary engine again, we need to make sure it wouldn't be just short-lived," said Kogai. "We need it to meet future emissions regulations. We are still conducting our R&D activity to overcome any issues we have with emissions and fuel efficiency."
Kogai says that the most likely application for the rotary would be as a range extender in an electric car.
Mazda made a rotary range-extender for a Mazda 2 three years ago. Google it, journos drove it. I think was mentioned on this thread a while back. They said they would like to also make a portable generator using a rotary to keep production figures up. Mazda stated that any new rotary would most probably have HCCI ignition. Also look at recent SPARCS and CREEV advancements from the UK in rotaries.
The rotary using SPARCS, CREEV and HCCI ignition is the perfect engine for a range-extender being a third of the size and weight of a piston engine. A range-extender engine is only a part time engine, so longevity is guaranteed.
https://en.wikipedia.org/wiki/wankel_engine?
Mazda have dropped the RX-Vision direct drive rotary engine sports car. That all makes sense. The rotary as a range-extender is by far the best application for this engine. They need to have high production levels which sports cars will not give them.
"Mazda–like the rest of the automotive industry–has put priority on introducing hybrid and electric cars in the face of tightening emissions regulations. The company has entered a partnership with Toyota to develop electrified vehicles."
Toyota is doing research on a free piston linear generator for hybrids. About 16 organisation around the world are doing so, and have been for over 20 years, and no one has perfected it yet.
https://en.wikipedia.org/wiki/Free-piston_linear_g...
The rotary looks the best bet for a small range extender engine. When on a constant speed & load the efficiency is better than piston engines.
"If we were to restart production of the rotary engine again, we need to make sure it wouldn't be just short-lived," said Kogai. "We need it to meet future emissions regulations. We are still conducting our R&D activity to overcome any issues we have with emissions and fuel efficiency."
Kogai says that the most likely application for the rotary would be as a range extender in an electric car.
Mazda made a rotary range-extender for a Mazda 2 three years ago. Google it, journos drove it. I think was mentioned on this thread a while back. They said they would like to also make a portable generator using a rotary to keep production figures up. Mazda stated that any new rotary would most probably have HCCI ignition. Also look at recent SPARCS and CREEV advancements from the UK in rotaries.
The rotary using SPARCS, CREEV and HCCI ignition is the perfect engine for a range-extender being a third of the size and weight of a piston engine. A range-extender engine is only a part time engine, so longevity is guaranteed.
https://en.wikipedia.org/wiki/wankel_engine?
Edited by RayTay on Wednesday 7th December 11:55
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