http://www.foxnews.com/story/0,2933,184980,00.html



I don't get it, at all. The automotive industry jumps on the "I want to make a environment-friendly combustion engine, but...it only has less than 1/3 the horsepower" bandwagon.


They couldn't have picked the Corvette. Not the SRTs....not the Lambos, or the Porches...nooo....


They had to do it to a rotary.

 

this has been around for a while now. I remember reading an article in Road and Track (if I remember right) where they drove it. It's interesting though, I guess hydrogen runs particularly well in a Rotary engine.

 

It does run "well" because of the combustion process of the rotary. But last I checked, hydrogen (atleast the way they're using it) doesn't have NEAR the volatility of gasoline.


Less boom, less zoom.

 

I did a huge research and design project. Hydrogen gives you more bang for your buck than gasoline, but the problem is that hydrogen gas takes up more volume than liquid gasoline, so the hydrogen fuel actually displaces air(oxygen). Hydrogen also has the fastest flame speed of any flammable substance from what i researched. Its also a better suited fuel for a rotary engine than a piston engine because of the lack of hot spots such as an exhaust valve.

If hydrogen was injected into an engine in the manner that diesel fuels are, thats is injected after the intake cycle so that the fuel doesn't displace any air, the combustion engine can make abotu 1/3 more power than compared with gasoline.

Another reason that rotaries are more likely to benefit from hydrogen is that rotary engine suffer from limited spark timing BTDC. There's a great article that was posted that covered the timing of a rotary and why there is a point where you can not advance it any more. The faster flame speed of hydrogen mean that less advance is needed to maximize the work done by the combustion gasses at high engine speeds.

Whew, i would love to have a discussion on this. I was wanting to convert my RX to H2 power, but i lack major funding.....but its very doable.

 

I've heard from one person that the RX-8 has no ***** at all and yet I've heard another person say that the only way you'll fully grasp its potential is by taking it out on the track and really winding it up. Which is correct?

 

Well that depends... I went to test drive one with a buddy of mine, and had the sales man in the passanger seat. I scared the shitout of him when I took off peeling out and taking a turn sideway's. I was happy with it, but the price is what turned me off. I could have gotten an Evo or Sti for the same price.

 

Laundryhamperman, an excellent insight indeed! However, in the application the hydrogen is being used, will it decrease the actual performance of the engine vs. gasoline?

 

if you used port injection like the current fuel injection setsups use, you will make less power, the approximate fraction you would make escapes me, but i know you still make more than half as much power. I may have to look this one up to confirm, but i believe that a stochiometically balanced mixture of H2 and air is about 30% H2 by volume.

 

I don't understand why people are so concerned about fuel economy, ect, ect. The worlds oil suplies can last well over 5000 years, but by the time 5k rolls around more oil will have formed. Even though you can argue it is not enviormently friendly, and its difficult to obtain this oil, auto manuhactures are wasting their time trying to create a new powersystem.

Auto manufactures should focus on a new fuel instead. Make a car run off of pure water is ideal but unrealistic, and hydrogen and oxygen alone do not combust as well as petrol. However, if one uses mehtanol alchol, from corn, or hey, the fuel source is supiror in all ways to petrol and completly renuable. The fuel burns cleaner, and better, and it give teh farmers something to grow, so it is good for teh economy. It will aslo create mass amounts of agricultral engineering jobs to replace the manny oil industry jobs being lost.

Methanol is also a proven reliable source, and there is a countrey and south america that already does this. WW II era aircraft frequently used methanol/water mixtures instead of nitrous oxide, because its not compressed, and provides better boosting. Formula one cars also use methanol as well I belive.

Methanol is the way of the future. ( that is my $0.02) BTW a German scientist proved plants produce methane gas which is a much worse green house gas tehn carbon monoxide, and carbon dioxide.

 

Not really, experts say the earth's resources has about 35 years of gasoline left.

 

am i blind, or does it say it can only travel 62miles when running on hyrdogen?

 

The biggest challenge of hydrogen powered cars is storing the hydrogen fuel. It has to be kept in special high pressure tanks that are very dangerous. I'm guessing Mazda used a very small tank thats very well insulated and protected to insure theres no reports of their early hydrogen carsbursting into flames. Besides, its just a limited production prototype, they'll change that if it goes into production.

 

Yeah, the tank in the H2 powered RX-8 is in the trunk and isn't very large.

I'd be kinda ironic if the rotary engine paved the way to a zero emissions hydrogen based internal combustion engine when you consider just how dirty and thirsty they are when fueled with gasoline.

 

?!?!? hydrogen has 52000btu/lb, nearly 3 times that of gasoline. i personally think it's pretty cool that the rotary might be the future powerplant of many cars. i bet ever other car company would be kicking themselves for not putting in the r and d that mazda did, if it pans out like that. think someone would come up to you and say yeah i got a new car and it's got a rotary....well mines been around for 22 years

 

According to the article, the car can run on gasoline OR hydrogen. That could be pretty cool if they worked it out properly. Think about it; how often do you really use all of your available horsepower? It doesn't take many ponys to maintain a typical cruising speed, right? What if it automatically switched between the two states? Use gas for getting up to speed, then hydro once you were there just to maintain that speed. If you need to pass someone, push the pedal down and it starts back into the gasoline useage. Just a thought...

 

Yeah, I think they said it has a switch on the dashboard that you flip between hydrogen and gasoline power, even while driving. It couldnt be hard to make it auto-switching with the RX-8's fly-by-wire throttle system.

The reason its "volatility" seems to be less is because hydrogen is far less dense at common temperatures than gasoline, so to get the same amount of hydrogen into a combustion chamber you either have to enlarge the chamber by alot or keep the hydrogen exceptionally cool.

 

Well gentlemen, looks like my generation is gonna suck. im 16 now and just starting cars.

But heres the great part of it for me, all the good cars will be used and all the hippie wagons in the future will be $$$.

So im gonna be the one on TV selling those great restored muscles lol

anywase back to the subject.
I cant believe there gonna do that. Its just not possable to make a car cry like that. dang my generation is gonna suck. I feel sorry for my future children.

 

IF ya think about it there actually giving the car a sex change.... know it has 2 parts instead of 1,,, weeeirrrddd.. but just plain wrong!

 

sweet...just enough to cover my lifespan

 

The latest projections I have seen is 18 years depending on the geometric growth in the demand for cars in China and India- that is nearly 3 billion people.

My first car at the age of three was a pedal car. The way fuel prices and supply are going it looks like my last will also be a pedal car. The first was a minature Bugatti, I must start work on a carbon fibre 1/3 size RX-7. Would you consider pedals going round and round to be rotary power?

 

hydrogen will explode when in contact with air, at least it did in my high school chemistry class.

methanol and water? alkyl outboard racing boats had loads of problems with water getting into the methanol and forming an azeotrope. Funniest thing, we'd run stock outboards on gasoline, and beat the methanol powered Konig racing motors because we could finish the race. Oh, they'd run great at the start of the race (50 mph), only to die and be passed up by me doing 25mph. It was a "battle of attrition">

 

yes but you're going to need 2.598 times as much air to burn that pound of hydrogen as you would need to burn a pound of typical gasoline. So with the same amount of air (38.191lbs) as it would take to burn a pound of hydrogen (and get 52000 BTUs.) you could burn 2.598 pounds of conventional gasoline (and get 47803 BTUs).

So yeah, there is more power potential in hydrogen, but not THAT much. Not to mention this is assuming the hydrogen and gasoline would have the same volume. This would mean cooling the hydrogen to a liquid state... which is not easy to do, especially in the trunk of a car.

 

only with a spark or something to start it.

 

As stated, hydrogen has more energy per lb. The problem is that hydrogen typically has much less energy per volume. One has to liquefy hydrogen to get a decent range. Even then, the tank is big and is much heavier than the fuel it is carrying. Also, to liquefy hydrogen, it takes roughly 1/3 of the energy content of the hydrogen to do so (300,000 BTUs of hydrogen takes something like ~100,000 BTUs to liquefy it).

The other problem, is that hydrogen currently is derived from fossil fuel (cracking methane). There is work currently being done on next generation nuclear reactors. Most of them are being designed for very high outlet temperatures (900 C or more). With these high temperatures, one can get higher efficiencies creating electricity. Also, with temperatures this high, one can potentially crack water molecules to produce hydrogen. This is much more efficient than using electrolysis. Besides, if you used electrolysis to make hydrogen, you are just moving the emissions from the cars to the oil/coal/etc. power plants to make the electricity.

It is interesting stuff. I think hybrids are the best option short term. As the technology advances, we can then get into hydrogen and other fuel types. One of the largest problems is going to be the infrastructure to deliver the hydrogen or whatever to stations for people to fill their cars.

 

35 years, 18 years, 5000 years...all of these figures come from "experts"

The number is dependent on where there funding is coming from...

<20 years-these guys are usually ag funded or fuel cell or possibily enviro nut job oil haters

<100 years-primarily the ag funded guys who know it will take a while to build up a crop supply of either corn, sugar cane or whatever to replace oil

>200-5000 years- these guys are oil guys who either know about plans for the oil companies to start ag projects or the guys who think we'll be able to get to the "deep" oil.

There is a lot of oil left, but it's very, very deep, and currently it's very difficult for most drill rigs to get it. But if it's down there they'll get it eventually.

Brazil has a lot of excess sugar cane and make a lot of Ethanol from it. Down there the car makers (names you know ..Ford..Chevy..etc) make "mixed" fuel cars that can run on ethanol or gas or a mix of both. So you can choose whatever is cheaper at that station and fill it up, EtOH and gasoline are mandated to be available at all service stations down there.
Brazil makes the majority of their EtOH from a process invovling sugar cane and for them it's competitively priced, so people actually use it.

Essentially the cars have a mass flow sensor on the fuel line and adjust the timing etc..to whatever the "mix" of gas and ethanol is about to be burned by the engine.

The EtOH/MeOH solution is probably the easiest, because the technical problems are confined to the fuel since we all know the combustion engine is very efficient as it is compared to other sources of "mobile" power.

Hydrids are very complicated compared to even a modern car, and currently every hybird Toyota sells it takes a loss. The economics don't work for hybrids, and compound the issue by safety considerations during accidents and disposal issues for the batteries etc..when they're lifespan is over.


And as far as "experts" go, remember most environmental science guys are all heavily funded by greenpeace and siera club type groups, the only ones that aren't are Russians.
The only ones that say global warming as a crisis is a overblown myth...the Russians.