Single mother in need of explanation

[Dumb_Blonde]

Thank you in advance for your time. I found a neat project to do with
my 14 year old son, but would like to know the science behind it so it
will be educational.

Here is the video link.

It is a fire cracker experiment, and I know he will love it, but I am
clueless as to how this makes my car run.

 

[**THE-RFI-EMI-GUY**]

I assume the can is open on one end like a soup can, not a coke can. I
think the water is there to provide an airtight, frictionless seal for
more effect. Keeping the firercracker dry is tricky. This looks like a
good use for the hundreds of firecrackers I have left over!

What he is simulating is the explosion that happens in one of your cars
engine cylinders. A car engine operates on a series of small controlled
explosions. In your car, the explosive force drives a piston down,
pushing a connecting rod which in turn rotates a crankshaft. A car
engine has 4 to 8 cylinders which fire sequentially and smoothly. The
links below illustrate this with a single cylinder like a lawnmower
engine. These are "internal combustion engines".

My sister did a similar science project years ago with a coffee can
fitted with a spark plug and filled with a very small amount of gasoline
or ether. A plastic lid was placed on top and an ignition coil made a
spark which blew the plastic lid off. Not as dramatic as a fire cracker.

http://www.keveney.com/otto.html
http://en.wikipedia.org/wiki/Four-stroke_cycle

Thank you in advance for your time. I found a neat project to do with
my 14 year old son, but would like to know the science behind it so it
will be educational.

Here is the video link.

It is a fire cracker experiment, and I know he will love it, but I am
clueless as to how this makes my car run.

--
Joe Leikhim K4SAT
"The RFI-EMI-GUY"©

"Treason doth never prosper: what's the reason?
For if it prosper, none dare call it treason."

"Follow The Money" ;-P

 

[Captain Midnight]

I assume the can is open on one end like a soup can, not a coke can. I
think the water is there to provide an airtight, frictionless seal for
more effect. Keeping the firercracker dry is tricky. This looks like a
good use for the hundreds of firecrackers I have left over!

What he is simulating is the explosion that happens in one of your cars
engine cylinders. A car engine operates on a series of small controlled
explosions. In your car, the explosive force drives a piston down,
pushing a connecting rod which in turn rotates a crankshaft. A car
engine has 4 to 8 cylinders which fire sequentially and smoothly. The
links below illustrate this with a single cylinder like a lawnmower
engine. These are "internal combustion engines".

My sister did a similar science project years ago with a coffee can
fitted with a spark plug and filled with a very small amount of gasoline
or ether. A plastic lid was placed on top and an ignition coil made a
spark which blew the plastic lid off. Not as dramatic as a fire cracker.

http://www.keveney.com/otto.html
http://en.wikipedia.org/wiki/Four-stroke_cycle

Their is no explosion in a properly operating internal combustion engine.
The fuel merely heats the air. The expansion of the air pushes the piston.
An explosion called detonation or knock can put a hole in the piston. Some
engines require higher octane fuel to keep knock from occurring.

 

[**THE-RFI-EMI-GUY**]

Its a matter of semantics. A arguably a hydrogen bomb simply heats up
surrounding air (and matter).

Their is no explosion in a properly operating internal combustion engine.
The fuel merely heats the air. The expansion of the air pushes the piston.
An explosion called detonation or knock can put a hole in the piston. Some
engines require higher octane fuel to keep knock from occurring.

--
Joe Leikhim K4SAT
"The RFI-EMI-GUY"©

"Treason doth never prosper: what's the reason?
For if it prosper, none dare call it treason."

"Follow The Money" ;-P

 

[Arfa Daily]

Their is no explosion in a properly operating internal combustion engine.
The fuel merely heats the air. The expansion of the air pushes the piston.
An explosion called detonation or knock can put a hole in the piston. Some
engines require higher octane fuel to keep knock from occurring.

That seems to me to be a misleading description of the principles of an
internal combustion engine. The fuel is mixed with the air in a very
carefully controlled ratio, highly compressed, and is then set light to,
either by a spark in the case of a gasoline engine, or by self ignition from
the rapid heating of the mixture during compression, in the case of a
diesel. It burns or combusts, and what comes out of the exhaust, after the
burning, is not air, but a fully reduced residue of the burning process. The
burning of the mixture under such intense pressure, in what is essentially a
fully contained space, takes place at such speed, it would usually be
considered to be representative of a controlled explosion. Detonation knock
is normally as a result of the timing of the ignition source not being ideal
for the engine in question. The detonation process should be started just
before the piston reaches top dead centre, so that by the time the burning
has spread fully from the initiating point - ie the spark plug - through the
entire mixture, and is thus at its fiercest, the piston has rolled over past
its point of being momentarily stationary, and is just beginning on its way
back down the cylinder. The rapidly burning ( exploding ? ) mixture will
then deliver maximum thrust to the piston, driving it down the cylinder
bore. If the mixture starts to burn too early, it will reach maximum energy
output before the piston has reached the top, so will oppose the upward
movement of the piston, which is still occuring, leading to the
pre-detonation knock.

Maybe it is just semantics, and some may disagree, but that has always been
my take on how an engine works, ever since I was first rebuilding them as a
kid, because I couldn't afford repair shop prices !!

Arfa

 

[Arfa Daily]

That seems to me to be a misleading description of the principles of an
internal combustion engine. The fuel is mixed with the air in a very
carefully controlled ratio, highly compressed, and is then set light to,
either by a spark in the case of a gasoline engine, or by self ignition
from the rapid heating of the mixture during compression, in the case of a
diesel. It burns or combusts, and what comes out of the exhaust, after the
burning, is not air, but a fully reduced residue of the burning process.
The burning of the mixture under such intense pressure, in what is
essentially a fully contained space, takes place at such speed, it would
usually be considered to be representative of a controlled explosion.
Detonation knock is normally as a result of the timing of the ignition
source not being ideal for the engine in question. The detonation process
should be started just before the piston reaches top dead centre, so that
by the time the burning has spread fully from the initiating point - ie
the spark plug - through the entire mixture, and is thus at its fiercest,
the piston has rolled over past its point of being momentarily stationary,
and is just beginning on its way back down the cylinder. The rapidly
burning ( exploding ? ) mixture will then deliver maximum thrust to the
piston, driving it down the cylinder bore. If the mixture starts to burn
too early, it will reach maximum energy output before the piston has
reached the top, so will oppose the upward movement of the piston, which
is still occuring, leading to the pre-detonation knock.

Maybe it is just semantics, and some may disagree, but that has always
been my take on how an engine works, ever since I was first rebuilding
them as a kid, because I couldn't afford repair shop prices !!

Arfa

Just as a matter of interest, I just looked up the word " explosion " at

http://dictionary.reference.com/browse/explosion

and interestingly, the first result, 5th definition, specifically mentions
the internal combustion engine. The third result, definition 1a also seems
to cover it neatly, as does the twelfth

Arfa

 

[Arfa Daily]

Just as a matter of interest, I just looked up the word " explosion " at

http://dictionary.reference.com/browse/explosion

and interestingly, the first result, 5th definition, specifically mentions
the internal combustion engine. The third result, definition 1a also seems
to cover it neatly, as does the twelfth

Arfa

Ah, it could be a question of semantics ! It's just occured to me what you
were saying. It is the pressure wave from the burning ( although I still
think " exploding " covers it also ) mixture that drives the piston down,
and not the actual burning mixture ( flame front is it called ? ), which
should not actually touch the top of the piston before it burns out, and can
cause damage, if it does. Yep ! that's it I reckon. We're both on the same
page now. Sorry ...

Arfa

 

[**THE-RFI-EMI-GUY**]

Just as a matter of interest, I just looked up the word " explosion " at

http://dictionary.reference.com/browse/explosion

and interestingly, the first result, 5th definition, specifically mentions
the internal combustion engine. The third result, definition 1a also seems
to cover it neatly, as does the twelfth

Arfa

I especially like this definition. In fact anyone who has watched a
nitro fueled dragster can attest to the violent explosive manner of
those engines exhaust. Those engine builders avoid "detonation" at all
costs.

1. A release of mechanical, chemical, or nuclear energy in a sudden
and often violent manner with the generation of high temperature
and usually with the release of gases.

Most people don't think of the explosive process going on within an
automobile engine because the process is very refined, by mufflers,
flywheels and engine timing.

--
Joe Leikhim K4SAT
"The RFI-EMI-GUY"©

"Treason doth never prosper: what's the reason?
For if it prosper, none dare call it treason."

"Follow The Money" ;-P

 

[Homer J Simpson]

Their is no explosion in a properly operating internal combustion engine.

Sure there is. But you want it at the correct time in the cycle. Knocking is
caused by misfiring.

 

[clifto]

That seems to me to be a misleading description of the principles of an
internal combustion engine. The fuel is mixed with the air in a very
carefully controlled ratio, highly compressed, and is then set light to,
either by a spark in the case of a gasoline engine, or by self ignition from
the rapid heating of the mixture during compression, in the case of a
diesel. It burns or combusts, and what comes out of the exhaust, after the
burning, is not air, but a fully reduced residue of the burning process.

To add to your excellent explanation, the byproducts of combustion, such
as carbon dioxide, together occupy more volume than the fuel-air mixture
did, and the heat generated by the rapid burn further increases the total
volume.

 

[Captain Midnight]

engine.

Sure there is. But you want it at the correct time in the cycle. Knocking is
caused by misfiring.

Detonation is all of the fuel burning at once(explosion). A proper flame
path will happen relatively slowly to push the piston(burn). The beginning
of the burn is timed to push the piston when the crank is in the proper
position. How long the burn lasts and it's timing is dependent on engine
design and application. If an explosion was acceptable there'd be no need
for high octane fuel. Apparently you've never seen a piston with a hole in
the crown. It's like the difference of flipping a light switch with your
finger or hitting it with a hammer.

Pinging is hot spots in the combustion chamber causing self ignition at the
wrong time. The extra heat from this can cause detonation though.

 

[mark krawczuk]

Detonation is all of the fuel burning at once(explosion). A proper flame

path will happen relatively slowly to push the piston(burn).

tell me what is the change over point at which a "slow burn" turns to a
explosion.
u want the fuel to burn slow , so teh engine runs slower ?

you are incorrect , dentonation is the IGNITING of fuel at the wrong time
..



hmmm of course its a explosion, i`ll put u in a petrol vapour filled room
with a sparkplug connected up to a engine , via a long plug lead, then i`ll
crank the engine over KABOOM !!!!of course its gonna explode.

 

[Captain Midnight]

Detonation is all of the fuel burning at once(explosion). A proper flame
tell me what is the change over point at which a "slow burn" turns to a
explosion.
u want the fuel to burn slow , so teh engine runs slower ?

you are incorrect , dentonation is the IGNITING of fuel at the wrong time


hmmm of course its a explosion, i`ll put u in a petrol vapour filled room
with a sparkplug connected up to a engine , via a long plug lead, then i`ll
crank the engine over KABOOM !!!!of course its gonna explode.

Seems you are also incapable of understanding the difference between burning
and an explosion too.

 

[Ancient_Hacker]

Detonation is all of the fuel burning at once(explosion). A proper flame> path will happen relatively slowly to push

The technical term is "High order reaction". The two options are:

(1) A flame front moves across the gas, taking milliseconds. That
what happen when you light a match, or a spark plug fires in a
properly operating innternal combustion engine.

(2) High order: The reaction starts instantly at many places throught
the materinal, as it's heated to its iginition point throughout.
Takes place in nano to microseconds. That's what most explosives do.

 

[Captain Midnight]

flame> path will happen relatively slowly to push

The technical term is "High order reaction". The two options are:

(1) A flame front moves across the gas, taking milliseconds. That
what happen when you light a match, or a spark plug fires in a
properly operating innternal combustion engine.

(2) High order: The reaction starts instantly at many places throught
the materinal, as it's heated to its iginition point throughout.
Takes place in nano to microseconds. That's what most explosives do.

Bingo! And it produces a shock wave that combustion does not.

 

[Michael A. Terrell]

flame> path will happen relatively slowly to push

Bingo! And it produces a shock wave that combustion does not.

Captain Midnight, huh? Tell me, what is the name of the street where
the abandoned C-band uplink earth station that you used to jam HBO with
?


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

 

[Captain Midnight]

Captain Midnight, huh? Tell me, what is the name of the street where
the abandoned C-band uplink earth station that you used to jam HBO with
?

http://www.macdougallelectronics.com/bio.html

 

[Michael A. Terrell]

http://www.macdougallelectronics.com/bio.html

I already know that, but where is the location of the earth station
used to Jam HBO, or even the name of the company that built the
equipment?


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

 

[mark krawczuk]

hi, read this "
There are three rates of combustion; ordinary combustion, explosion (Rapid
Combustion), and detonation..


look around onthe net , hmmmmm rapid combustion , err COMBUSTION !!!!! OR
EXPLOSION,.... i am right.

 

[mark krawczuk]

no one challenging me .........
]