16X Technical observations
Momentum Keeps Me Going
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From: Colorado
How does the saying go? .... hydrogen is the fuel of the future and always will be lol. I'm not sure I believe it for all eternity, but it's certainly going to be a while at least in the US.
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From: Waukesha Wisconsin
well yes, but i dont know how effecient its gonna be, cause the hydrogen bmw has a v12, but it only puts out 260 horse. but the rotary is more effecient with hydrogen, so we will see
http://www.bmwusa.com/uniquelybmw/ef...mics?panelid=4
http://www.bmwusa.com/uniquelybmw/ef...mics?panelid=4
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From: Colorado
Not a rubber melter but sure as hell fun to drive
and zero emmissions would make it that much cooler.
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From: Waukesha Wisconsin
well mazda does say that a rotary engine is a lot more efficent than an otto cycle engine with hydrogen, but only time will tell.
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Hydrogen has an octane rating of between 130-140 using standard ASTM test methods which are based on compression detonation of somewhat more complex molecules then hydrogen alone. H2 tends to have a very tiny and elusive footprint compared to any hydrocarbon. In short H2 is extremely resistent to detonation at conventional compression ratios (9:1-12:1). Better yet H2 is far more resistent to detonation in an irregular shaped chamber (as opposed to the rounder shape of a piston chamber). Therefore the ignition timing can be fired much earlier putting more of the heat to mechanical energy as opposed to throwing it out the tailpaipe.
Piston-free 07.11.2007
Joined: Apr 2005
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From: Madison, WI
I think I understand, kinda.
Hydrogen has a given resistance to detonation, which, put simply, is uncontrolled supersonic combustion caused by high engine temps that will cause damage to said engine. This resistance to detonation is a given fuel's octane rating.
So basically, the characteristics of a rotary engine (high compression, irregular combustion chamber) promote a greater octane rating in a hydrogen/air mixture versus the same mixture in a piston engine. So that means the rotary can run hotter on hydrogen than a piston engine, which will have to ignite the mix closer to it's exhaust cycle so as to regulate heat and therefore prevent detonation. Igniting later gives the fuel/air mix's heat less time to push on the piston. If you ignite earlier, the engine holds the hot gas in longer...heating up the engine...causing detonation...destroying the engine.
Yes/no?
Hydrogen has a given resistance to detonation, which, put simply, is uncontrolled supersonic combustion caused by high engine temps that will cause damage to said engine. This resistance to detonation is a given fuel's octane rating.
So basically, the characteristics of a rotary engine (high compression, irregular combustion chamber) promote a greater octane rating in a hydrogen/air mixture versus the same mixture in a piston engine. So that means the rotary can run hotter on hydrogen than a piston engine, which will have to ignite the mix closer to it's exhaust cycle so as to regulate heat and therefore prevent detonation. Igniting later gives the fuel/air mix's heat less time to push on the piston. If you ignite earlier, the engine holds the hot gas in longer...heating up the engine...causing detonation...destroying the engine.
Yes/no?
Last edited by RWagz; Nov 7, 2007 at 09:08 PM.
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From: Houston
That high octane number is worthless as hydrogen burns way too fast to be useful as a fuel for an internal combustion engine. That's why it will never be a viable alternative. You need too large of an engine to get squat in power in return. Aside from some environmentalist whacko, who in their right mind would use hydrogen when they can use gasoline, diesel fuel, cow turds, or any other superior fuel source and make more power in the same engine? I wouldn't. If global warming is the only thing that hydrogen helps with, allow me to be the first to say I'd rather just pollute more. I always will. I am not willing to be inconvenienced because someone can't understand that power and performance is the single most important consideration when it comes to fuel.
Octane rating is less important than the speed of the flame front. Proof is this is diesel fuel. Although rated in Cetane and not Octane, if there were an octane rating it would be somewhere between 20 and 40. That's it. Look at the power you can get with it. It all has to do with flame front speed. The slower it is, the easier it is to control. Octane is relatively unimportant with today's technology and certainly nothing to be basing the viability of a fuel on. Hydrogen is a crap alternative pure and simple and I have no doubt it will remain this way in my lifetime.
Octane rating is less important than the speed of the flame front. Proof is this is diesel fuel. Although rated in Cetane and not Octane, if there were an octane rating it would be somewhere between 20 and 40. That's it. Look at the power you can get with it. It all has to do with flame front speed. The slower it is, the easier it is to control. Octane is relatively unimportant with today's technology and certainly nothing to be basing the viability of a fuel on. Hydrogen is a crap alternative pure and simple and I have no doubt it will remain this way in my lifetime.
That high octane number is worthless as hydrogen burns way too fast to be useful as a fuel for an internal combustion engine. That's why it will never be a viable alternative. You need too large of an engine to get squat in power in return. Aside from some environmentalist whacko, who in their right mind would use hydrogen when they can use gasoline, diesel fuel, cow turds, or any other superior fuel source and make more power in the same engine? I wouldn't. If global warming is the only thing that hydrogen helps with, allow me to be the first to say I'd rather just pollute more. I always will. I am not willing to be inconvenienced because someone can't understand that power and performance is the single most important consideration when it comes to fuel.
Octane rating is less important than the speed of the flame front. Proof is this is diesel fuel. Although rated in Cetane and not Octane, if there were an octane rating it would be somewhere between 20 and 40. That's it. Look at the power you can get with it. It all has to do with flame front speed. The slower it is, the easier it is to control. Octane is relatively unimportant with today's technology and certainly nothing to be basing the viability of a fuel on. Hydrogen is a crap alternative pure and simple and I have no doubt it will remain this way in my lifetime.
Octane rating is less important than the speed of the flame front. Proof is this is diesel fuel. Although rated in Cetane and not Octane, if there were an octane rating it would be somewhere between 20 and 40. That's it. Look at the power you can get with it. It all has to do with flame front speed. The slower it is, the easier it is to control. Octane is relatively unimportant with today's technology and certainly nothing to be basing the viability of a fuel on. Hydrogen is a crap alternative pure and simple and I have no doubt it will remain this way in my lifetime.
You also have to consider the methods of harvesting hydrogen. You may be cleaner at the tail pipe but in no way does a hydrogen vehicle reduce the environmental footprint of an automobile, all things considered.
While it may catch favor with politicans and big oil companies I guess it all goes back to the roots of the same phrase we agreed upon before:
Since when has something being the WORST possible solution to a problem stopped anyone from implementing it?
Piston-free 07.11.2007
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From: Madison, WI
Exactly, the most efficient method to produce hydrogen involves processing natural gas, and it releases a LOT of CO2. So we're still killing the environment and still dependent on fossil fuels in a hydrogen economy.
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From: Waukesha Wisconsin
thats why i said that hydrogen seems very inefficent, i mean come on, a V12, that only puts out 260 hp! thats pathetic. But i dont think that the oil companies will like this so much, because hydrogen will be used whether we like it or not, and the oil companies will lose money. everyone is on the saving energy binge now a days, and as soon as normal cars have hydrogen fuel in them, people will buy them like crazy. At least gas prices will go down though.
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From: portland oregon
give me one of these from honda
http://www.motortrend.com/features/a...10_tokyo_tech/
and that 16x in one of these
http://www.energycurrent.com/index.p...3&storyid=6425
and i can go back and forth to work all week long and take my kid to day care on one fill up and heat the water for my house
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Detonation must be one of the most misunderstood charteristics of an internal combustion motor. A few points to think about;
Detonation is a spontaneous ignition - away from the flame front. It takes heat transferred with a large enough dose to ignite spontaneously.
There are 3 sources of thermal transfer;
Conduction
Convection
Radiant
Conduction comes from interacting with a solid such as the metal walls. If they get hot enough to ignite the mixture then you have a bigger (and pemanent) problem then detonation.
Convection is the flamefront. It travels at the speed of sound which in a typical internal combustion motor (heat/pressure) about 2000 feet per second. But when the fuel is ignited by the kernal that isn't detonation.
That leaves radiant heat. Infrared (IR) energy. Infrared is not a simple energy to understand. What is simple to understand is IR travels at - tada - the speed of light. I'll skip the disseration on absorption and emission of IR leave it at this;
The source of heat for detonation is primarily the infrared energy liberated by the combustion. Various materials in the chamber be they solids, liquids, or gases will affect the amount of heat energy absobed by the fuel at any particular point outside the combustion envelope.
The most conventional material change is in the fuel - exchanging the straight hydrocarbon chains like pentane, hexane, heptane for more cyclic chains like cyclohexane and di-methyl/tri-methyl groups.
Now lets take that just a step further; Its not so much the hydrogen that absorbs enough energy to make love to a local oxygen. The hydrogen has to share that heat with it's beloved oxygen and typically by itself won't absorb as much as a larger mass carbon will. The carbon has a much higher affinity to absorbing the IR heat and conducts that heat to the hydrogen - often enough to liberate the hydrogen or two - which then look for a date with a local oxygen pair.
Fuel is not the only way to manage reduction in detonation.
Back to the hydrogen a moment. The combustion velocity of hydrogen is rather slow in a 20% O2 environment. Not even half the velocity of methane which tends to burn pretty well in a piston motor. If you've ever seen the video of the Graf Hindenburg burn then compared that with a natural gas well fire it's pretty evident which has a higher combustion velocity.
Solve the inherent detonation problem of a rotary and piston motors will become extinct. Lets hope that Mazda brings that one step closer with the 16X.
Detonation is a spontaneous ignition - away from the flame front. It takes heat transferred with a large enough dose to ignite spontaneously.
There are 3 sources of thermal transfer;
Conduction
Convection
Radiant
Conduction comes from interacting with a solid such as the metal walls. If they get hot enough to ignite the mixture then you have a bigger (and pemanent) problem then detonation.
Convection is the flamefront. It travels at the speed of sound which in a typical internal combustion motor (heat/pressure) about 2000 feet per second. But when the fuel is ignited by the kernal that isn't detonation.
That leaves radiant heat. Infrared (IR) energy. Infrared is not a simple energy to understand. What is simple to understand is IR travels at - tada - the speed of light. I'll skip the disseration on absorption and emission of IR leave it at this;
The source of heat for detonation is primarily the infrared energy liberated by the combustion. Various materials in the chamber be they solids, liquids, or gases will affect the amount of heat energy absobed by the fuel at any particular point outside the combustion envelope.
The most conventional material change is in the fuel - exchanging the straight hydrocarbon chains like pentane, hexane, heptane for more cyclic chains like cyclohexane and di-methyl/tri-methyl groups.
Now lets take that just a step further; Its not so much the hydrogen that absorbs enough energy to make love to a local oxygen. The hydrogen has to share that heat with it's beloved oxygen and typically by itself won't absorb as much as a larger mass carbon will. The carbon has a much higher affinity to absorbing the IR heat and conducts that heat to the hydrogen - often enough to liberate the hydrogen or two - which then look for a date with a local oxygen pair.
Fuel is not the only way to manage reduction in detonation.
Back to the hydrogen a moment. The combustion velocity of hydrogen is rather slow in a 20% O2 environment. Not even half the velocity of methane which tends to burn pretty well in a piston motor. If you've ever seen the video of the Graf Hindenburg burn then compared that with a natural gas well fire it's pretty evident which has a higher combustion velocity.
Solve the inherent detonation problem of a rotary and piston motors will become extinct. Lets hope that Mazda brings that one step closer with the 16X.
Detonation must be one of the most misunderstood charteristics of an internal combustion motor. A few points to think about;
Detonation is a spontaneous ignition - away from the flame front. It takes heat transferred with a large enough dose to ignite spontaneously.
There are 3 sources of thermal transfer;
Conduction
Convection
Radiant
Conduction comes from interacting with a solid such as the metal walls. If they get hot enough to ignite the mixture then you have a bigger (and pemanent) problem then detonation.
Convection is the flamefront. It travels at the speed of sound which in a typical internal combustion motor (heat/pressure) about 2000 feet per second. But when the fuel is ignited by the kernal that isn't detonation.
That leaves radiant heat. Infrared (IR) energy. Infrared is not a simple energy to understand. What is simple to understand is IR travels at - tada - the speed of light. I'll skip the disseration on absorption and emission of IR leave it at this;
The source of heat for detonation is primarily the infrared energy liberated by the combustion. Various materials in the chamber be they solids, liquids, or gases will affect the amount of heat energy absobed by the fuel at any particular point outside the combustion envelope.
The most conventional material change is in the fuel - exchanging the straight hydrocarbon chains like pentane, hexane, heptane for more cyclic chains like cyclohexane and di-methyl/tri-methyl groups.
Now lets take that just a step further; Its not so much the hydrogen that absorbs enough energy to make love to a local oxygen. The hydrogen has to share that heat with it's beloved oxygen and typically by itself won't absorb as much as a larger mass carbon will. The carbon has a much higher affinity to absorbing the IR heat and conducts that heat to the hydrogen - often enough to liberate the hydrogen or two - which then look for a date with a local oxygen pair.
Fuel is not the only way to manage reduction in detonation.
Back to the hydrogen a moment. The combustion velocity of hydrogen is rather slow in a 20% O2 environment. Not even half the velocity of methane which tends to burn pretty well in a piston motor. If you've ever seen the video of the Graf Hindenburg burn then compared that with a natural gas well fire it's pretty evident which has a higher combustion velocity.
Solve the inherent detonation problem of a rotary and piston motors will become extinct. Lets hope that Mazda brings that one step closer with the 16X.
Detonation is a spontaneous ignition - away from the flame front. It takes heat transferred with a large enough dose to ignite spontaneously.
There are 3 sources of thermal transfer;
Conduction
Convection
Radiant
Conduction comes from interacting with a solid such as the metal walls. If they get hot enough to ignite the mixture then you have a bigger (and pemanent) problem then detonation.
Convection is the flamefront. It travels at the speed of sound which in a typical internal combustion motor (heat/pressure) about 2000 feet per second. But when the fuel is ignited by the kernal that isn't detonation.
That leaves radiant heat. Infrared (IR) energy. Infrared is not a simple energy to understand. What is simple to understand is IR travels at - tada - the speed of light. I'll skip the disseration on absorption and emission of IR leave it at this;
The source of heat for detonation is primarily the infrared energy liberated by the combustion. Various materials in the chamber be they solids, liquids, or gases will affect the amount of heat energy absobed by the fuel at any particular point outside the combustion envelope.
The most conventional material change is in the fuel - exchanging the straight hydrocarbon chains like pentane, hexane, heptane for more cyclic chains like cyclohexane and di-methyl/tri-methyl groups.
Now lets take that just a step further; Its not so much the hydrogen that absorbs enough energy to make love to a local oxygen. The hydrogen has to share that heat with it's beloved oxygen and typically by itself won't absorb as much as a larger mass carbon will. The carbon has a much higher affinity to absorbing the IR heat and conducts that heat to the hydrogen - often enough to liberate the hydrogen or two - which then look for a date with a local oxygen pair.
Fuel is not the only way to manage reduction in detonation.
Back to the hydrogen a moment. The combustion velocity of hydrogen is rather slow in a 20% O2 environment. Not even half the velocity of methane which tends to burn pretty well in a piston motor. If you've ever seen the video of the Graf Hindenburg burn then compared that with a natural gas well fire it's pretty evident which has a higher combustion velocity.
Solve the inherent detonation problem of a rotary and piston motors will become extinct. Lets hope that Mazda brings that one step closer with the 16X.
sorry lol, had to. Good information, definitely interesting
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Joined: Jul 2002
Posts: 21,958
Likes: 115
From: portland oregon
hindenberg was NOT a hydrogen fire
Detonation must be one of the most misunderstood charteristics of an internal combustion motor. A few points to think about;
Detonation is a spontaneous ignition - away from the flame front. It takes heat transferred with a large enough dose to ignite spontaneously.
There are 3 sources of thermal transfer;
Conduction
Convection
Radiant
Conduction comes from interacting with a solid such as the metal walls. If they get hot enough to ignite the mixture then you have a bigger (and pemanent) problem then detonation.
Convection is the flamefront. It travels at the speed of sound which in a typical internal combustion motor (heat/pressure) about 2000 feet per second. But when the fuel is ignited by the kernal that isn't detonation.
That leaves radiant heat. Infrared (IR) energy. Infrared is not a simple energy to understand. What is simple to understand is IR travels at - tada - the speed of light. I'll skip the disseration on absorption and emission of IR leave it at this;
The source of heat for detonation is primarily the infrared energy liberated by the combustion. Various materials in the chamber be they solids, liquids, or gases will affect the amount of heat energy absobed by the fuel at any particular point outside the combustion envelope.
The most conventional material change is in the fuel - exchanging the straight hydrocarbon chains like pentane, hexane, heptane for more cyclic chains like cyclohexane and di-methyl/tri-methyl groups.
Now lets take that just a step further; Its not so much the hydrogen that absorbs enough energy to make love to a local oxygen. The hydrogen has to share that heat with it's beloved oxygen and typically by itself won't absorb as much as a larger mass carbon will. The carbon has a much higher affinity to absorbing the IR heat and conducts that heat to the hydrogen - often enough to liberate the hydrogen or two - which then look for a date with a local oxygen pair.
Fuel is not the only way to manage reduction in detonation.
Back to the hydrogen a moment. The combustion velocity of hydrogen is rather slow in a 20% O2 environment. Not even half the velocity of methane which tends to burn pretty well in a piston motor. If you've ever seen the video of the Graf Hindenburg burn then compared that with a natural gas well fire it's pretty evident which has a higher combustion velocity.
Solve the inherent detonation problem of a rotary and piston motors will become extinct. Lets hope that Mazda brings that one step closer with the 16X.
Detonation is a spontaneous ignition - away from the flame front. It takes heat transferred with a large enough dose to ignite spontaneously.
There are 3 sources of thermal transfer;
Conduction
Convection
Radiant
Conduction comes from interacting with a solid such as the metal walls. If they get hot enough to ignite the mixture then you have a bigger (and pemanent) problem then detonation.
Convection is the flamefront. It travels at the speed of sound which in a typical internal combustion motor (heat/pressure) about 2000 feet per second. But when the fuel is ignited by the kernal that isn't detonation.
That leaves radiant heat. Infrared (IR) energy. Infrared is not a simple energy to understand. What is simple to understand is IR travels at - tada - the speed of light. I'll skip the disseration on absorption and emission of IR leave it at this;
The source of heat for detonation is primarily the infrared energy liberated by the combustion. Various materials in the chamber be they solids, liquids, or gases will affect the amount of heat energy absobed by the fuel at any particular point outside the combustion envelope.
The most conventional material change is in the fuel - exchanging the straight hydrocarbon chains like pentane, hexane, heptane for more cyclic chains like cyclohexane and di-methyl/tri-methyl groups.
Now lets take that just a step further; Its not so much the hydrogen that absorbs enough energy to make love to a local oxygen. The hydrogen has to share that heat with it's beloved oxygen and typically by itself won't absorb as much as a larger mass carbon will. The carbon has a much higher affinity to absorbing the IR heat and conducts that heat to the hydrogen - often enough to liberate the hydrogen or two - which then look for a date with a local oxygen pair.
Fuel is not the only way to manage reduction in detonation.
Back to the hydrogen a moment. The combustion velocity of hydrogen is rather slow in a 20% O2 environment. Not even half the velocity of methane which tends to burn pretty well in a piston motor. If you've ever seen the video of the Graf Hindenburg burn then compared that with a natural gas well fire it's pretty evident which has a higher combustion velocity.
Solve the inherent detonation problem of a rotary and piston motors will become extinct. Lets hope that Mazda brings that one step closer with the 16X.
I appreciate the exceptional tech talk but can you elaborate on the inherent detonation problem in the rotary?
Paul.