Cold Gas
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Nope! Just plain no.
There would be no gain by cooling the gas. Cooling the air is the prevent knock (that is pre-detonation), it isn't to directly impact power generation (other than allowing higher piston speeds, greater compression ratio, and more spark advance).
Also, someone mentioned colder fuel being more dense...this is also way off base. I dont really want to type out a full explanation, but yeah, not the case.
Rocket fuel is typically liquid oxygen and liquid hydrogen. Both of these substances are gas at room temperature (and well below that too). They are kept cold to prevent them from vaporizing into a gas and causing really bad things to happen (tanks exploding and such). Very different concept here.
There would be no gain by cooling the gas. Cooling the air is the prevent knock (that is pre-detonation), it isn't to directly impact power generation (other than allowing higher piston speeds, greater compression ratio, and more spark advance).
Also, someone mentioned colder fuel being more dense...this is also way off base. I dont really want to type out a full explanation, but yeah, not the case.
Rocket fuel is typically liquid oxygen and liquid hydrogen. Both of these substances are gas at room temperature (and well below that too). They are kept cold to prevent them from vaporizing into a gas and causing really bad things to happen (tanks exploding and such). Very different concept here.
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From: Covington WA, USA
Originally Posted by duboseq,Oct 5 2007, 05:27 AM
Does'nt the Space Shuttle and NASA keep fuel cold for launches?
They use liquid oxygen and hydrogen. They have to keep that cold in the storage tanks. But they run the fuel in tubes around the rocket nozzle. This simultaneously cools the nozzle and heats up the fuel. Heating up the fuel allows it to burn better than it would if it were still a supercooled liquid.
Trust me or look it up, but I'm aerospace engineer who works with combustion. The primary concern when mixing the fuel and air is to atomize the fuel -- to break it up into very small droplets. This is easiest done for a hydrocarbon fuel when it is warm.
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Originally Posted by slalom44,Oct 4 2007, 02:14 PM
The benefit of cooling the gas is insignificant to the benefit to cooling the air intake. Here's why:
Gasoline is a liquid. The specific heat of gasoline is relatively low - about half of the specific heat of water. That means that cooling a gallon of gas requires half as much energy removal as a gallon of water.
But gasoline combusts as a gas, not a liquid. To get the vaporized gas one degree colder, you would have to reduce the temperature of liquid gasoline by over 200 degrees!
On top of that, Air is only 21% oxygen. Almost one fifth of the air is Nitrogen, which doesn't burn. That means that you would have to cool the gasoline vapor five times as much to get the same effect as cooling the air.
Gasoline is a liquid. The specific heat of gasoline is relatively low - about half of the specific heat of water. That means that cooling a gallon of gas requires half as much energy removal as a gallon of water.
But gasoline combusts as a gas, not a liquid. To get the vaporized gas one degree colder, you would have to reduce the temperature of liquid gasoline by over 200 degrees!
On top of that, Air is only 21% oxygen. Almost one fifth of the air is Nitrogen, which doesn't burn. That means that you would have to cool the gasoline vapor five times as much to get the same effect as cooling the air.
cold gas wouldn't evaporate as fast
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From: Covington WA, USA
Originally Posted by PalenkosBro,Oct 5 2007, 01:23 PM
and besides.......liquids evaporate faster in the HEAT
cold gas wouldn't evaporate as fast
cold gas wouldn't evaporate as fast
These things are systems. You can't just take one thing from one design and assume it will work with another one.
In the case of a stock S2000 motor, it is designed to be run on ambient temperature gas. Most likely both cooling the gas or heating it would be taking it out of the temperature range it was designed for.
Heating it would allow it to atomize better, but it might cause detonation problems. Cooling it would help raise the detonation limit but would require different fuel injectors to fix the resulting atomization problem.
Also, you want the fuel to be liquid when it is in the fuel injector. The injectors are designed to spray a fine mist of liquid droplets and get them mixed into the gasseous air in the combustion chamber. You would want an entirely different kind of mixer device if you were mixing two gasses with each other.
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Originally Posted by mikegarrison,Oct 5 2007, 02:43 PM
It also won't detonate as soon. If the drag racers were seeing some benefit from cold fuel, it was probably because they had higher compression engines and otherwise had problems with detonation.
These things are systems. You can't just take one thing from one design and assume it will work with another one.
In the case of a stock S2000 motor, it is designed to be run on ambient temperature gas. Most likely both cooling the gas or heating it would be taking it out of the temperature range it was designed for.
Heating it would allow it to atomize better, but it might cause detonation problems. Cooling it would help raise the detonation limit but would require different fuel injectors to fix the resulting atomization problem.
Also, you want the fuel to be liquid when it is in the fuel injector. The injectors are designed to spray a fine mist of liquid droplets and get them mixed into the gasseous air in the combustion chamber. You would want an entirely different kind of mixer device if you were mixing two gasses with each other.
These things are systems. You can't just take one thing from one design and assume it will work with another one.
In the case of a stock S2000 motor, it is designed to be run on ambient temperature gas. Most likely both cooling the gas or heating it would be taking it out of the temperature range it was designed for.
Heating it would allow it to atomize better, but it might cause detonation problems. Cooling it would help raise the detonation limit but would require different fuel injectors to fix the resulting atomization problem.
Also, you want the fuel to be liquid when it is in the fuel injector. The injectors are designed to spray a fine mist of liquid droplets and get them mixed into the gasseous air in the combustion chamber. You would want an entirely different kind of mixer device if you were mixing two gasses with each other.
That said, it sounds to me like you guys are pretty sure about this, and I'm inclined to trust your technical understanding which is no doubt better than mine in this case.
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Originally Posted by MikeyCB,Oct 5 2007, 01:55 PM
Sure I realize that these systems were designed to operate under certain conditions, but make all kinds of changes like introducing more air, more fuel, lower temperatures, etc etc, and then we adjust the program to consider these changes. We enable the engine to intake better, we let it exhaust better but ECU programs and adjustments help maximize the benefits of these abilities.
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Originally Posted by mikegarrison,Oct 5 2007, 02:59 PM
Notice I specified "stock motor".
Realistically, when we're getting into fuel system modification, forced induction, etc we're stepping outside of the original design consideration though and have already left concern for stock operation behind.
Considering the other side of things then, would a benefit been seen at all to an increase in gas temperature? You guys talked about atomization and the benefits of the heat, so is that at all realistic in terms of a performance increase?
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I don't know but Honda engineering has probably come close to maximising performance outta this engine.
Anything short of major alterations isn't going to gain you much.
Forget about heating or cooling gas. Maybe experimenting with cold air flow might be a slight benefit but then again maybe not.
You have to believe that Honda has envisioned all possible ways for improvement.
Anything short of major alterations isn't going to gain you much.
Forget about heating or cooling gas. Maybe experimenting with cold air flow might be a slight benefit but then again maybe not.
You have to believe that Honda has envisioned all possible ways for improvement.
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Originally Posted by RED MX5,Oct 5 2007, 05:16 AM
In the sense that fuel is burned, they're the same, but there also significant differences. In the case of a rocket using LOX, LOX is colder than the dry ice used to chill gasoline, and not only that, the LOX provides the oxigen for combustion, so the idea of cold air or fuel to increase charge density really doesn't fit into the equation. Rockets don't suck in air to make power so things are quite a bit different.
Air:
Nitrogen N2 78.084%
Oxygen O2 20.947%
Argon Ar 0.934%
Carbon Dioxide CO2 0.033%
Neon Ne 18.2 parts per million
Helium He 5.2 parts per million
Krypton Kr 1.1 parts per million
Sulfur dioxide SO2 1.0 parts per million
Methane CH4 2.0 parts per million
Hydrogen H2 0.5 parts per million
Nitrous Oxide N2O 0.5 parts per million
Xenon Xe 0.09 parts per million
Ozone O3 0.07 parts per million
Nitrogen dioxide NO2 0.02 parts per million
Iodine I2 0.01 parts per million
Carbon monoxide CO trace
Ammonia NH3 trace
Rounding things out it's 80% N2 and 20% O2, and that was probably the basis of the original statement that people are picking nits over. If that's the case, then the statement wasn't really wrong at all and the objections are/were just a bit anal.
Air:
Nitrogen N2 78.084%
Oxygen O2 20.947%
Argon Ar 0.934%
Carbon Dioxide CO2 0.033%
Neon Ne 18.2 parts per million
Helium He 5.2 parts per million
Krypton Kr 1.1 parts per million
Sulfur dioxide SO2 1.0 parts per million
Methane CH4 2.0 parts per million
Hydrogen H2 0.5 parts per million
Nitrous Oxide N2O 0.5 parts per million
Xenon Xe 0.09 parts per million
Ozone O3 0.07 parts per million
Nitrogen dioxide NO2 0.02 parts per million
Iodine I2 0.01 parts per million
Carbon monoxide CO trace
Ammonia NH3 trace
Rounding things out it's 80% N2 and 20% O2, and that was probably the basis of the original statement that people are picking nits over. If that's the case, then the statement wasn't really wrong at all and the objections are/were just a bit anal.
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From: Longmont, CO
Chilling the fuel in the tank would allow you to run more fuel in the available tank volume. (Which is why F1 does it, I've heard.) I have no idea what effect it would have on the combustion of the fuel, though. "The standard coefficient of gasoline's expansion/contraction equals 0.069% per degree Fahrenheit."
http://www.consumerwatchdog.org/resources/...elUSAJune07.pdf
Therefore, a 50 liter tank, like the S2000 has, holds as much fuel at 32F as a 52.346 liter tank at 100F. That extra 2.346 liters, at a 2 mile per lap track, at 9 mpg (about what I get at the track) means two extra laps per refueling.
Rockets use liquid oxygen and liquid hydrogen so they can store a lot of it in their tanks. In gaseous form they'd never be able to hold enough fuel to do anything.
http://www.consumerwatchdog.org/resources/...elUSAJune07.pdf
Therefore, a 50 liter tank, like the S2000 has, holds as much fuel at 32F as a 52.346 liter tank at 100F. That extra 2.346 liters, at a 2 mile per lap track, at 9 mpg (about what I get at the track) means two extra laps per refueling.
Rockets use liquid oxygen and liquid hydrogen so they can store a lot of it in their tanks. In gaseous form they'd never be able to hold enough fuel to do anything.