Should Electric vehicle be banned?

[xxChrisxx]

but additional electricity has to come from thermal power stations . I think manufacture keep their hands clean by saying that "they produce emission free 90% efficient electric cars, the thermal power stations are inefficient but that's their problem". what manufactures going to do to improve 90 % efficient electric motor I think they will add automatic groceries ordering system in the next generation cars.

Jesus. NOTE: THERMAL POWERSTATIONS AND DEVELOPMENT OF IC ENGINES ARE NOT THE SAME THING. kthx

Thermal powerstations aren't inefficient, there is a thermodynamic efficincy limit to cycles such as this, they are as efficient as they can be within a sensible cost. Not only that they are pretty much the most efficient way we have of generating electricity. Also most new power stations are CHP so they have a utilisation ratio of 1 of all input heat. Most the power goes to making electricity, the waste goes to heating.

A progressive switch to nuclear power plants, totally solves the problem of greenhouse gas emissions. Reduces the amount of oil we need. It just required people to stop irrationally dismissing it. You say Nuclear Power to someone, they will immedately respond Chernobyl. Ignoring the fact that about 80% of electricity in France is generated in nuclear power plants with a fantastic safety record.



So far the only argument you have for 'BAN THE ELECTRIC CAR' is they will use more electricity.
It's been shown that even fledgling electric cars can be made to run as well as the most efficient oil burner (with 120 years wirth of development), whilst being cheaper to charge and running with similar emissions. The IC engine is nearing the end of it's life now, it's reached maturity and will at some point in the near future enter a decline phase. (SEE: product life cycle). The electric car is in the transition from birth to growth. There are still some major technical challenged to be sorted before EV become viable for widespread use, but that's what develoment is for.

It does not make sense to stop the development of new products to put money into developing things that are reaching the end of their life. Don't get me wrong the IC engine has not yet reached it's full potential, but it's getting there.
So I put the question back to you? Do you think they should ban the electric car and why? Well formed thoughts only, not ctrl+c, ctrl+v from crackpot sites please.

 

[russ_watters]

one way or another nuclear power is going to make a comeback so the power plant efficiency/pollution argument carries a lot less weight than it would have 10 years ago.

 

[mgb_phys]

Also most new power stations are CHP so they have a utilisation ratio of 1 of all input heat. Most the power goes to making electricity, the waste goes to heating.

In northern climates - in most of the US the largest part of domestic electricity usage is AC (electricity per head is something like 4x higher in Houston than NY), getting rid of heat profitably isn't as easy.

The big advantage of electric cars is that they constitute a vast distributed power storage scheme. Once you have enough electric cars hooked upto smart meters then unreliable sources like wind power become a lot more practical.

 

[mheslep]

EDIT: I'm going to clarify my position on this. I don't agree that big 4x4 are inherently less safe than a small car, just that they don't increase overall road safety. This is mainly down to the type of driver behind the wheel.


If you drive around a very large modern car YOU INSIDE are more safe from a shunt of given magnitude than someone in an older/smaller car.

I don't know about overall road safety; that's a nebulous phrase, but fair enough, it is clear what you are saying about size.

 

[mheslep]

Go away. We are having a nice conversation about safety in this hijacked thread.

The tesla is also cheaper to refuel given night electricity rates. I pay about 12p per kWh (I can't find a real figure, this seems semi sensible). As you say it takes 58 kWh. Coming to a grand total of £6.96 to charge something that will get you 200 miles. £6.96 will now get you about 5.5 lites of diesel (1.2 gallons imp) giving you a total range of 84 miles in the polo.

Yes. Or put another way, the same 200 miles of energy in that diesel Polo will cost £17 versus the Tesla's £7, and that cost difference can only grow as the price of oil inevitably goes up.

 

[mgb_phys]

the same 200 miles of energy in that diesel Polo will cost £17 versus the Tesla's £7

But only £0.35 of the £7 is tax, whereas £10.50 of the £17 is tax - there is no way that's going to continue!

 

[gmax137]

The big advantage of electric cars is that they constitute a vast distributed power storage scheme. Once you have enough electric cars hooked upto smart meters then unreliable sources like wind power become a lot more practical.

That makes sense if the winds are blowing at night, when the majority of the cars will be charging. But, does wind 'peak' at night? Or, are we going to have charging stations in the parking lot at work?

Also, don't batteries have a finite number of charge cycles? If it's *my* battery, why would I let the grid wear it out? Or are the power companies going to let me use their batteries?

These are genuine questions, not an attack on your statement...

EDIT: I think your concern about taxes is right on. I hadn't really even thought of it myself.

 

[Topher925]

That makes sense if the winds are blowing at night, when the majority of the cars will be charging. But, does wind 'peak' at night? Or, are we going to have charging stations in the parking lot at work?

Also, don't batteries have a finite number of charge cycles? If it's *my* battery, why would I let the grid wear it out? Or are the power companies going to let me use their batteries?

These are genuine questions, not an attack on your statement...

EDIT: I think your concern about taxes is right on. I hadn't really even thought of it myself.

Peak wind capacity is usually during the day, roughly around 2pmish in most windy locations. I doubt there would be charging stations at any business as charging stations cost a lot of money.

Yes, batteries do have a finite number of cycles and letting your car act as a load buffer would shorten its battery's lifespan. Using cars to buffer the load of the grid is a neat idea, but not a very efficient or economic one considering energy could be better stored at the location of power plants.

 

[mheslep]

I don't know how wide spread this is, but in many areas in the midwest US, http://www.uwig.org/opimpactspaper.pdf" , wind is a little higher at night, for example:

[...]Xcel currently has an aggregate wind plant within its control area of about 280 MW capacity located at Lake Benton, Minnesota. Annual capacity factor of the wind plant is about 30%, [...]. Historical data of the wind energy production shows a modest diurnal pattern with slightly higher production at night.

Which is nice but not a requirement for wind to complement EVs. Whenever wind actually does peak, it can be used to offset more expensive natural gas plants, and then the gas plants can run at night if needed. (Gas plants are cheap to build but expensive to run, thus there's a lot gas plants sitting idle[1]).

In some smaller early adopter areas - http://www.betterplace.com/images/photos/B_342.jpg" , Denmark - charge points are due to be installed throughout the country - several hundred thousand total, in shopping areas, office parks, residences. So yes charging during the day, and night, is anticipated there.

Batteries do have a cycle life. Newer Li Ion chemistry achieves http://www.a123systems.com/a123/technology/life" before losing 10% of permanent capacity if the temperature and charge/discharge rate is not extreme. [2] Thus the question of how long the battery 'lasts' over time depends on the mainly size of the battery installed in your vehicle. If it's small, enough for say only five miles, then the average driver will 'kill' such a battery in ~20,000 miles of 100% charge/discharge cycles. If the battery is larger, the size used in the forthcoming EV's (100 miles / 25 kWh), it should easily outlive the vehicle - and thus have plenty of cycles left to loan to the grid - though it complicates the end of life cost of the vehicle considerably.

There are a couple of business models in play right now for battery ownership. One is you own the battery as part of the vehicle (Nissan Leaf, Chevy Volt, etc), buy it upfront adding ~$10-12k to the vehicle price and you might well object to the grid pulling power from it without a complicated power+cycle compensation plan arrangement with a utility company (one? many?). The other model is battery leasing (Renault Fluence), so the vehicle upfront cost is ~$10-12k less than model one. With the odd battery exchange station around the vehicle owner really doesn't care about cycle life, and the grid power pull/push arrangement can be part of the one-time battery lease agreement.

[1] See total US gas electric installed capacity http://www.eia.doe.gov/cneaf/electricity/epa/epat1p2.html" at 21.4% of total.
[2] Also see cycle life assessments by ANNL:
http://www.ipd.anl.gov/anlpubs/2008/02/60978.pdf, tables 3,4
http://pubs.its.ucdavis.edu/publicat...il.php?id=1292, table 1

 

[mgb_phys]

Peak wind capacity is usually during the day, roughly around 2pmish in most windy locations.

That depends on the location and offshore vs inland. If wind is to be more than a decimal point worth of the supply you need something like this.

I doubt there would be charging stations at any business as charging stations cost a lot of money.

So do parking spaces, businesses are prepared to let you park for free to persuade you to shop there rather than at a competitor.

Yes, batteries do have a finite number of cycles and letting your car act as a load buffer would shorten its battery's lifespan.

A lot of that is about thermal management, allowing a smart meter to charge your car for 20mins in any hour is better for the battery than the high power charge/discharge of regenerative braking.

considering energy could be better stored at the location of power plants.

600MW worth of power storage capacity at the power station is pricey. Currently pumped storage schemes cost more per KWH than the wind farms that would be using them - effectively it doubles the cost of renewable energy.

Smart metering and 'optimized' $$$ charging schemes are definitely coming - look how profitable billing is for cable and cellphone companies, the power generators want some of that action.

At the moment to cope with peak demand the power company has to run up gas stations which cost 50% more to operate than baseline coal - it also has to have these stations maintained and manned ready when not used. So when everybody turns on the kettle in an ad break in Pop idol t really costs them. Also unless you have a really good grid you need a lot of gas stations serving each area.
Back in the days of 4 TV channels and 30million viewers for a program the grid used to publish demand charts showing the peaks which matched ad breaks in soaps!

 

[sr241]

but there are losses in transmission of electricity and it increases with current,in high current(amp) charging stations these losses are high.
finding new hydro power stations are difficult and it will cut forest or forests will be sink in water. in wind power stations power density per area is low. thermal power stations are only as efficient as engines. fission reactors produce hazardous waste and fuel like uranium are limited. economically viable fusion reactors are 50-100 years away. so why hurry for EVs, why don't manufactures try to increase efficiency of IC engines or use alternative IC engine designs like new gen rotary engines

 

[mgb_phys]

why don't manufactures try to increase efficiency of IC engines or use alternative IC engine designs like new gen rotary engines

What do you think they have been doing for 120years?

The problem is that this needs public support - lobby your senator / congressman to have them repeal the 2nd law of thermodynamics.

 

[xxChrisxx]

why don't manufactures try to increase efficiency of IC engines or use alternative IC engine designs like new gen rotary engines

Are you aware of the phrase "diminishing returns"?

Plus, rotaries are rubbish if you want economy. FACT. As they all have
a) poor compression.
b) poor sealing.

They are inherent problems with the design. Just like a positive displacement engine has the disadvantage of big heavy pistons flying up and down.

 

[Topher925]

There are some significant fuel efficiency improvements that can be made with DISI engines but until someone figures out how to get the NOx emissions down, you'll never see them in the US in widespread use.

As stated above, rotary engines are pretty much complete garbage when it comes to automotive applications. I don't think any fundamental change in geometry of the engine will help much with efficiency anyway. Really the only thing that can be improved is the combustion process, not necessarily the geometry of the compression components.

 

[xxChrisxx]

There are some significant fuel efficiency improvements that can be made with DISI engines but until someone figures out how to get the NOx emissions down, you'll never see them in the US in widespread use.

Seriously, they won't see widesperead use, why? That is the single biggest advancement in engine technology there's been in years. Make petrol like a diesel, and you ramp up the efficiency. NOx and particulate emissions are pretty low. Is this why diesels aen't used over there?

 

[mgb_phys]

NOx emisions are lower because of the low ignition temperature but this increase the particulate emissions. You can fix this with filters and secondary burning but it costs more and so unless oil is expensive enough to counter this.

The problem in the US is that individual states can set limits, so for a long time it wasn't worth launching a diesel in the US if some major markets didn't allow them and if you owned a diesel you couldn't drive across certain states because there was no filling stations.

There is also possibly a bit of politics / protectionism.
So a 1.2L diesel hatchback is banned because it's emissions (g/cc) are over the limit while a 6L V8 pickup truck with much higher overall emission mass is allowed.

 

[mheslep]

NOx emisions are lower because of the low ignition temperature but this increase the particulate emissions. You can fix this with filters and secondary burning but it costs more and so unless oil is expensive enough to counter this.

The problem in the US is that individual states can set limits,

Not generally, but only with the permission of the US government EPA, and they have made exceptions especially for CA.

 

[mgb_phys]

Not generally, but only with the permission of the US government EPA, and they have made exceptions especially for CA.

Has that changed recently?
I was asking the VW dealer why I couldn't get a diesel Golf over here and there were a few states that banned diesel for consumer vehicles (this was a few years ago)

So you got the catch 22, not only did people in say, NJ not buy diesels but nobody in NY did because they couldn't fill them up if they drove through NJ.

 

[mheslep]

Has that changed recently?
I was asking the VW dealer why I couldn't get a diesel Golf over here and there were a few states that banned diesel for consumer vehicles (this was a few years ago)

So you got the catch 22, not only did people in say, NJ not buy diesels but nobody in NY did because they couldn't fill them up if they drove through NJ.

Well of course anyone can buy diesel fuel everywhere in the US. Maybe some states have permission to ban the sale of diesel cars in their states, though I'd not heard this. I thought the problem was that US EPA had set extremely high particulate standards, maybe unreasonable ones, for the light duty vehicle fleet.

 

[Mech_Engineer]

VW USA makes few TDI option vehicles that are 50-state legal as far as I know. I personally own a 2006 Jetta TDI and love it; it gets about 45 mpg on the highway, and 40 mpg in mixed driving.

Available models:

Golf TDI (Available in 2-door and 4-door)
http://www.vw.com/global/hybrid/hybridMLP/assets/images/golf/golf_2door_tdi.jpghttp://www.vw.com/global/hybrid/hybridMLP/assets/images/golf/golf_4door_tdi.jpg
http://www.vw.com/golf/en/us/?tab=tdi

Jetta TDI
http://www.vw.com/global/hybrid/hybridMLP/assets/images/jetta/jetta_tdi_candyWhite.jpg
http://www.vw.com/jetta/en/us/

Jetta SportWagen TDI
http://www.vw.com/global/hybrid/hybridMLP/assets/images/jettasportwagen/jsw_tdi_candyWhite.jpg
http://www.vw.com/jettasportwagen/en/us/?tab=tdi

Touareg TDI (very expensive)
http://www.vw.com/global/hybrid/hybridMLP/assets/images/touareg/touareg_v6tdi_camp_white.jpg
http://www.vw.com/touareg/en/us/?tab=tdi

 

[mgb_phys]

Just checked - the 2008 Jetta was the first diesel to be available in all states (basically the last few states mandated low sulphur diesel)

 

[Mech_Engineer]

Just checked - the 2008 Jetta was the first diesel to be available in all states (basically the last few states mandated low sulphur diesel)

I think you mean 2009 Jetta (unless you mean production year rather than model year), there were no Jetta TDI's in 2007 or 2008.

 

[russ_watters]

but there are losses in transmission of electricity and it increases with current,in high current(amp) charging stations these losses are high.

No.

in wind power stations power density per area is low.

So what?

thermal power stations are only as efficient as engines.

So what?

fission reactors produce hazardous waste and fuel like uranium are limited.

Not really, no.

...why don't manufactures try to increase efficiency of IC engines...

They are, but there are some pretty hard limits, so there isn't all that much more that can be gained.

...or use alternative IC engine designs like new gen rotary engines

Because hoaxes don't power cars.

sr241, we generally don't fault people for ignorance, but we do require people to make an effort to learn and be reasonable. You're really going to need to start improving your posts here. Virtually everything you say is wrong, pointless or just plain gibberish.

 

[Topher925]

Seriously, they won't see widesperead use, why? That is the single biggest advancement in engine technology there's been in years. Make petrol like a diesel, and you ramp up the efficiency. NOx and particulate emissions are pretty low. Is this why diesels aen't used over there?

NOx emissions with DISI engines are not low, they are extremely high. So high that they are not even close to being able to meet US emission regulations. Its not only NOx, but also HC and soot emissions as well. DISI engines are extremely harmful to the environment (as of today) as far as automotive engine technology goes so to have a country with as many cars as the US does would have a significant negative impact on the environment.

Diesels aren't used so much for similar reasons (also cost) although they have gotten a lot better. They're still not as clean as their gasoline counterparts, especially at high loads, but emission production is steadily improving.

 

[sr241]

but there are losses in transmission of electricity and it increases with current,in high current(amp) charging stations these losses are high.

No.

can you explain? You think there is no loss in transmission of electricity from power station to home.
please tell me why transformers are used to increase voltage during transmission. also refer Ohm's law

thermal power stations are only as efficient as engines.

So what?

so why don't you use engines in cars

fission reactors produce hazardous waste and fuel like uranium are limited.

Not really, no.

can you explain? is nuclear waste doesn't produce harmful radiations and uranium is considered as rare Earth materials

...why don't manufactures try to increase efficiency of IC engines...

They are, but there are some pretty hard limits, so there isn't all that much more that can be gained.

but there is lot of potential in waste energy recovery in engines. many new rotary engines from independent inventors implements it.

...or use alternative IC engine designs like new gen rotary engines

Because hoaxes don't power cars.

you think hoaxes are pulling Mazda RX8(Wankel) and your lawn mover(quasi turbine engine), chain saw( again rotary) and some air crafts.

since this is physics forum you need theoretical support for what you say. you can not blindly say crackpot when those inventions have sound theoretical support

 

[Mech_Engineer]

can you explain? is nuclear waste doesn't produce harmful radiations and uranium is considered as rare Earth materials

Nuclear waste is sensationalized due to a general public lack of knowledge as to radiation, its effects, and mitigations. Compared to other forms of energy generation, nuclear is near the top of the list for cleanest, and at the top of the list IMO for "power of the future."

Additionally, Uranium is definitely not going to run out any time soon.

"Economic uranium resources will last for over 100 years at 2006 consumption rates, while it is expected there is twice that amount awaiting discovery. With reprocessing and recycling, the reserves are good for thousands of years."
- http://en.wikipedia.org/wiki/Uranium#Resources_and_reserves

but there is lot of potential in waste energy recovery in engines. many new rotary engines from independent inventors implements it.

Wankels are generally inefficient IC engines without very large turbochargers, due to their relatively low compression ratios. If an IC engine is going to make it into the future, it will be a turbodiesel due to its high compression ratio (hence higher efficiency than most IC's) and ability to utilize a wide variety of fuels.

you think hoaxes are pulling Mazda RX8(Wankel) and your lawn mover(quasi turbine engine), chain saw( again rotary) and some air crafts.

Yes the RX-8 uses a Wankel, but it's really more of a technology stunt than proof it's the engine of the future. It burns oil, needs tons of revs (9000+) to get any significant power, and gets poor mileage compared to "standard" 4-cylinder engines.

Wankel powered chainsaws, lawnmowers, and aircraft are generally rare, and have comparable (or worse) performance characteristics than similarly sized 4-stroke engines. They aren't engines of the future, period.

 

[mgb_phys]

There might be a niche for novel engines in say hybridish Smart-car sized vehicles where a 500-900cc engine generates electricity directly and the wheels are always electric drive. Then you don't have to worry about revs or torque or need crankshafts and gearboxes.

Not sure what you would call them but designs like a Deltic where two pistons operate together without a cylinder head have some advantages.

 

[sr241]

If an IC engine is going to make it into the future, it will be a turbodiesel due to its high compression ratio (hence higher efficiency than most IC's) and ability to utilize a wide variety of fuels.

There are other ways to increase efficiency like implementation of constant volume heat addition. it will increase efficiency and power at the rate of 50% . if you have seen PV diagrams and know about time losses in piston engines you will understand this. new engines like Anyoon rotary engine implements it without any mechanical complexity, it also implements Atkinson cycle (used in Prius) without any additional mechanical system. this new engine has leak proof 100% effective 3D sealing system, newly developed for it.
[PLAIN]http://7250345801171461223-a-1802744773732722657-s-sites.googlegroups.com/site/anyoonrotaryengine/pv-diagram/PV%20Diagram.jpg?attachauth=ANoY7cq5IHPVyneUMoJi6WCztIfiRQwkBUBVyrBBfnGqUDVnIJ-AItdE3NvT623LR4Xh5COX4Nrs9r-KEA6uiFVjDNsmnRVJHt685MaSgVz9ysLWhx4ZMhgXuXWe1sQLfkdVW3aq8z2pnw6s06Mx5BB4JHydwZe4Ijc9Tn4YaWaDlBXQrEvWT5vctqoua34E9gH6plJmzvVVXHDKb316Wd7ScfySO5Orampx0pf1fiVzZcz_3VfAYUw%3D&attredirects=0

 

[xxChrisxx]

NOx emissions with DISI engines are not low, they are extremely high. So high that they are not even close to being able to meet US emission regulations. Its not only NOx, but also HC and soot emissions as well. DISI engines are extremely harmful to the environment (as of today) as far as automotive engine technology goes so to have a country with as many cars as the US does would have a significant negative impact on the environment.

Diesels aren't used so much for similar reasons (also cost) although they have gotten a lot better. They're still not as clean as their gasoline counterparts, especially at high loads, but emission production is steadily improving.

Are we talkign about the same thing here GDI (direct injection engines)? If we are then Europe has managed to make them work. Take a look at VW new range of FSI engined cars, the emissions are all within euro 5 (I think it is now) regulations.

Granted they have more NOx emissions than a standard petrol engine, and the standard pertrol has no particulate but CO2 and unburnt HC are both lower. But the thing about GDI is that they allow for more powerful units in smaller packages, that's where you get the efficiency savings.

Thats why emissions from FSI units are lower per km traveled when compared to a standard injection engine, it allows higher boost pressures and more downsizing.

My mk4 gti is the 1.8T version and puts out 150bhp, the modern 1.4 TSI puts out 158bhp and less emissions. All thanks to more boost and FSI.

 

[xxChrisxx]

There are other ways to increase efficiency like implementation of constant volume heat addition.

So making it like a diesel then...
Which is precisely what car makers are doing.

it will increase efficiency and power at the rate of 50% . if you have seen PV diagrams and know about time losses in piston engines you will understand this. new engines like Anyoon rotary engine implements it without any mechanical complexity, it also implements Atkinson cycle (used in Prius) without any additional mechanical system. this new engine has leak proof 100% effective 3D sealing system, newly developed for it.

His graph is also totall crap, the cycle simply won't work like that. What his graph is showing is that all the fuel is burned INSTANTLY. As volume on that graph can easily be substituted for the rotary equivilant of crank angle. There is a finite burn time for fuel, it can be made to be incredibly small, but it's impossible to be instant.

Atkinson cylce is fair enough, there are gains to be had there.EDIT: If you don't mind me asking, what do you do for a living? As you are seeming arguing using only that site as a reference, and thus are arguing from a flawed position.

 

[sr241]

actually in Anyoon engine sufficient time is given for constant volume heat addition. about 30 degrees of rotation are given where volume of combustion chamber is remained same during combustion takes place. only 30 degree is required versus 90 degrees in piston engine for complete combustion since in Anyoon engine volume of gas during entire combustion is very low or equal to the volume of combustion chamber.

 

[russ_watters]

can you explain? You think there is no loss in transmission of electricity from power station to home.

No, it isn't that there is none, it's just that it is very small and doesn't follow that it increases with amperage. Why? Because when people need to send higher amperages they use bigger wires!

so why don't you use engines in cars

Huh?

Anyway, with car engine efficiency, once you've added a turbocharger and a heat recovery steam cycle, there really isn't much left. And those are old technology - they just aren't used because it costs money to put them in the car and until now, you'd never get that money back in fuel savings.

can you explain? is nuclear waste doesn't produce harmful radiations and uranium is considered as rare Earth materials

MechE said "sensationalized", I'd go so far as to say hoaxed. The nuclear waste issue is in essence one big lie perpetrated by the radical anti-nuclear power fringe in the 1960s and 1970s that now most people believe. The fact of the matter is that more than 95% of supposed nuclear "waste" is recyclable. When you are ultimately done with it it is far less radioactive than when dug out of the ground, except for that few percent. What's left can easily be stored: unlike pollution from cars and coal plants, which cannot be stored with existing technology.

Air pollution mostly due to cars and coal power plants kills about 20,000 people in the US every year. Except for the rare industrial accidents (ie, construction workers falling off ladders, etc.), nuclear power has never killed anyone in the US. And no one unassociated with the production of the power.

but there is lot of potential in waste energy recovery in engines. many new rotary engines from independent inventors implements it.

There's some, but not as much as you think. And those "independent inventors" either just don't know what they are talking about or are hoaxsters. The one you linked is such a hoax as it included obviously bogus efficiency numbers far above the theoretical maximum for a simple combustion cycle.

you think hoaxes are pulling Mazda RX8(Wankel) and your lawn mover(quasi turbine engine), chain saw( again rotary) and some air crafts.

The RX8 engine isn't anything special - it is the ones from "independent inventors" such as the one you linked that are hoaxes.

since this is physics forum you need theoretical support for what you say. you can not blindly say crackpot when those inventions have sound theoretical support

Lol, no. Burden of proof is always in the court of the one making the extrordinary claim. Fortunately for an "inventor", proving the claim is easy: they just have to submit their engine for testing. That they don't should give you a clue that they haven't really invented what they say/think they have. Besides which the "sound theoretical support" on that site contained laughably silly points, such as one place referencing a efficiency number using 2000C as the high temperature.

 

[xxChrisxx]

you think hoaxes are pulling Mazda RX8(Wankel) and your lawn mover(quasi turbine engine), chain saw( again rotary) and some air crafts.

since this is physics forum you need theoretical support for what you say. you can not blindly say crackpot when those inventions have sound theoretical support

How did I not spot this before?

1. You have been harping on about efficiency. Let's take the only true pistonless rotary you mentioned the RX8 Wankel.

Has a huge surface area to volume ratio vs a piston engine, meaning a higher amount of heat transfer from the combusion chamber to the block. This reduced efficiency. Doesn't seal as well as a piston engine. You get fresh charge seeping into the adjacent chamber and going stright out the exhaust. It also means it burns oil. Has a low compression ratio which reduced efficiency.

The upshot of this is that it gets about 15-25mpg. The most I have seen from the 238bhp version is 27 on long distance cruising. On the plus side it's light, it goes like stink and doesn't vibrate.The difference between the Wankel rotary and this new thing are:

The Wankel desn't make excessive efficiency claims based on an overly optimistic look at a pv diagram.
The Wankel has proved to work on extended driving this other one hasn't, although the seals are still something that requires constant maintainence.
The Anyoon's claim of 100% sealing, when there is no evidence of a practical seal test is simply annoying. I can tell you something for nothing, a rubber polymer pushing a metal seal on something that is close to combusion temperatues will not last for very long. There is a reason pistons use metal-metal seals.EDIT: That Anyoon engine will certainly run if it's built, I'm not saying it's a total crock of faecal matter. Just it really won't do what the inventor says it will.

 

[sr241]

for sealing Anyoon uses flourosilicone rubber ( can withstand above 400c) which is used in space shuttle nozzle bushes. and typical piston ring temp in engine is 220C refer "Engineering Fundamentalsof the Internal Combustion Engine byWillard W. Pulkrabek chapter ten page315"
So there is no question of lasting of seals

Besides which the "sound theoretical support" on that site contained laughably silly points, such as one place referencing a efficiency number using 2000C as the high temperature.

what is wrong with calculating Carnot efficiency between 2000k and 300k it is said 85% if you have new method for calculating Carnot efficiency please give me I will send it to laughter therapists (they will use it for those having difficulty in laughing).

 

[Topher925]

Are we talkign about the same thing here GDI (direct injection engines)? If we are then Europe has managed to make them work.

No, we are not. GDI usually refers to just directly injecting fuel instead of having a port injector before the intake valve(s) and is still essentially the otto cycle. DISI usually refers to stratified charge combustion and is more similar to the diesel cycle. I know, its a stupid and confusing naming convention.

As far as GDI goes, just about every major auto manufacturer has their own form of it. Ford has their EcoBoost, and a lot of the japanese companies like Mitsubishi and Nissan have been selling cars with GDI since the 90's. While GDI does provide a little better fuel economy and greater power density, it still mostly operates around the stoichiometric region and has some differences compared to DISI.

DISI, or stratified charge combustion engines, are unthrottled and rely directly on the amount of fuel injected to control power output. They typically operate at very lean stoichiometry and have very high compression ratios. Because of this they can operate at much higher efficiencies than your typically GDI engine. The problem is that since they operate at overall very lean conditions, have higher compression ratios (more heat), and the charge is stratified, they generate considerable amounts of NOx and HC. While the HC's can be removed with filtering the NOx is very difficult to get rid of. You can't just pass it through a 3-way cat because of the amount of oxygen that's present in the exhaust stream.