One more thing is a cooler intake charge will not reduce the combustion temp since the cooler the intake charge the more oxigen and fuel u can pack into an engine, the more violent the explosion of the charge will be hence increasing the combustion temp..
water is H2O, where O represents oxygen. when water dries or gets heated up it changes form into air frm liquid. It only changes form. the oxygen (O) is still there to support combustion. when we talk about air, it is the oxygen content that we are concerned with. therefore, theorethically, this mist thing does improve power or better combustion or wateva u wanna call it.Originally posted by slacker@Mar 31 2004, 15:55
Hmm/... The VE I guess it seems you are right.. I need to read up on that. IT seems that I ddn't understand the theory fully but anyways.. I still say that a mist of water will slightly reduce performance.. at best there will be no effect.
One more thing is a cooler intake charge will not reduce the combustion temp since the cooler the intake charge the more oxigen and fuel u can pack into an engine, the more violent the explosion of the charge will be hence increasing the combustion temp..
I did not say with cooler intake charge... I said "with water saturation"
Anyway.. let's break it down.. why do we get an increase in HP when temperature is low? because when temperature is lower air density increases. And with higher air density, mass flow will be increased. Okay.. that's settled.
In a closed system. The mass flow rate at point A must equal the the mass flow rate at point B...
So the total mass entering the combustion chamber must equal the mass of air as read at the MAF plus the mass of the mist of water plus the mass of fuel.
It doesn't matter what the water does because mass of air at pt A must equal mass of air at pt B.
So... Fuel and the mass of air is the same but there is water in the chamber
Some of the energy that could otherwise be used to propel the cylinder downward has been used to convert water into steam and steam into superheated steam.....
Thus this explains why I believe that there will be a reduction in performance due to aquamist type devices... :blink:
true that the fuel gets heated up when it enters the hot combustion chamber. getting heated up would mean that it absorbs heat from the surrounding area like the air it has mixed with. my thinking is that if the fuel was initially cooler to begin with, it would absorb more heat from the intake air it atomises or vapourises in, cooling down the air further, making it denser.Originally posted by ae92levin@Dec 27 2004, 01:34
rollo:
the fuel only gets heated up when it goes into the combustion chamber. fuel is still cool in ur petrol tank.
i remember 1 fellow who did this in his 2nd gen civic. he ran the fuel line between the fuel pump & the carb float bowl along the aircon tube hose which transports the aircon gas from the cooling coil evaporator back to the compressor & wrapped them closely together. the aircon gas in this hose was cold enough to help cool the fuel. he said the effect is that the engine feels more alive. so i guess the cool fuel would have helped cool the air it mixed with as the air-fuel mixture travels from the carb down through the intake manifold & finally into the combustion chambers, and also the cooled fuel would be denser & more energy content per unit volume.Originally posted by ae92levin@Dec 28 2004, 00:49
fair enough u have a point. however there is no point cooling the air when its already in the combustion chamber as the amount of oxygen would remain the same. lets not forget why we want cooler air in the first place.
also, cooling the fuel would require energy, and lost of power would occur there. we know how much power we lose from air conditioners alone. lets not imagine how much we lose cooling liquid/petrol.
i suddenly remembered reading somewhere that when (not too excessive) water droplets turn into steam in the combustion chamber of an internal combustion engine, the expansion of steam would help push down the piston in the power stroke, just like in those old reciprocating steam engines used in the old steam locomotives. it may not help increase power but it may help reduce fuel consumption as less fuel is required to push the same piston down.Originally posted by slacker@Mar 31 2004, 15:55
Some of the energy that could otherwise be used to propel the cylinder downward has been used to convert water into steam and steam into superheated steam.....
Thus this explains why I believe that there will be a reduction in performance due to aquamist type devices... :blink:
Actually what we need to aid combustion is just O2. H20 remains H20 even when combusted. The hydrogen ions/atoms and the oxygen atoms won't be separated with this process.Originally posted by ae92levin@Dec 27 2004, 01:34
water is H2O, where O represents oxygen. when water dries or gets heated up it changes form into air frm liquid. It only changes form. the oxygen (O) is still there to support combustion. when we talk about air, it is the oxygen content that we are concerned with. therefore, theorethically, this mist thing does improve power or better combustion or wateva u wanna call it.
sad thing is, the increase would be so small u wouldnt even feel it. better save ur time n money on other things. if stuff like that actually works it would come straight off the factory..
rollo:
the fuel only gets heated up when it goes into the combustion chamber. fuel is still cool in ur petrol tank.
Does all this make sense??
Originally posted by rollo+Dec 27 2004, 23:25 -->
QUOTE (rollo @ Dec 27 2004, 23:25 ) i wonder whether anyone has tried cooling down the fuel first before it mixes with the air. theoretically that should help cool down the air-fuel mixture.[/b]
Yeah, they do sell fuel coolers --QuoteBegin-rollo |
@Dec 28 2004, 19:51 i suddenly remembered reading somewhere that when (not too excessive) water droplets turn into steam in the combustion chamber of an internal combustion engine, the expansion of steam would help push down the piston in the power stroke, just like in those old reciprocating steam engines used in the old steam locomotives. it may not help increase power but it may help reduce fuel consumption as less fuel is required to push the same piston down. my 2¢[/quote] Yeah, but energy is from the fuel that was supposed to be used to move the cylinder has been used to expand the water vapour. |
Maybe natural gas has a lower energy rating and the systems using natural gasses are less efficient? Natural gas combustion doesn't have as much development as our conventional systems.Originally posted by rollo@Dec 27 2004, 23:25
i began thinking about this when i found out from some city taxi drivers that there would be some power loss felt when running on natural gas as compared to petrol. one factor is that as natural gas did not require atomisation or vapourisation, it does not absorb heat from the air it mixes with. in contrast, petrol needs to be atomised or vapourised when it mixes with air and it would absorb heat from that air.
just my thoughts...
Originally posted by slacker+Dec 29 2004, 02:40 -->
QUOTE (slacker @ Dec 29 2004, 02:40 )
Originally posted by rollo@Dec 27 2004, 23:25
i wonder whether anyone has tried cooling down the fuel first before it mixes with the air. theoretically that should help cool down the air-fuel mixture.
Yeah, they do sell fuel coolers
[/b]
i've seen such a cooler being offered for sale by a US company & it looks a smaller version of an oil cooler. that company also mentioned that this heat exchange device can be used to cool the ATF. however, i can't remember the brand name or that company name.
|
Yeah, but energy is from the fuel that was supposed to be used to move the cylinder has been used to expand the water vapour. [/quote] i've also read some where that in the absence of any water droplets as in a normal conventional combustion process, the air-fuel mixture burns, creating heat & also the carbon dioxide & other stuff which expands to push down the piston. when there are also water droplets present before the combustion, the air-fuel mixture also burns & also creating heat, carbon dioxide & other stuff like before but now the water droplets gets turned into steam by the heat and this steam also expands in the cylinder, giving a helping hand. |
Originally posted by slacker+Dec 29 2004, 02:43 -->
QUOTE (slacker @ Dec 29 2004, 02:43 ) --QuoteBegin-rollo
@Dec 27 2004, 23:25
i began thinking about this when i found out from some city taxi drivers that there would be some power loss felt when running on natural gas as compared to petrol. one factor is that as natural gas did not require atomisation or vapourisation, it does not absorb heat from the air it mixes with. in contrast, petrol needs to be atomised or vapourised when it mixes with air and it would absorb heat from that air.
just my thoughts...
Maybe natural gas has a lower energy rating and the systems using natural gasses are less efficient? Natural gas combustion doesn't have as much development as our conventional systems. [/b][/quote] according to paragraph 4.9 of this gasoline faq at http://www.faqs.org/faqs/autos/gasoline-faq/part1/ , the energy content per unit mass for natural gas is higher than that of petrol/gasoline. admittedly, i was made to understand that the engines in our ngv taxis r still optimally tuned to run on petrol but not so on natural gas bcos these engines were factory tuned on petrol before the taxis were fitted with natural gas/petrol dual fuel systems. by right, an engine optimally tuned for natural gas would take advantage of natural gas RON of more than 100 (120, i think) which would mean higher compression ratios & more aggressive ignition timing advance curves. but if so, such an engine would run poorly on RON97 petrol. my 2 cents. |