Improved Efficiency / Combustion Engines Explosion

[Flytox]

... Whereas for 30% of additional compression, at the same amount of mixture, the torque increases by almost 30%.

This seems a little optimistic .... There is another problem, the series engines are not sized for such a compression increase. It might be necessary to limit in the wake engine speed etc ...

Something else, on Diesel increase indefinitely the compression does not increase the yield indefinitely .... so the mechanical efficiency of the mobile equipment decreases.

Solution: turn a diesel block into gas!

[iridium]

The engine speed and compression have nothing to do.
It is the materials of the moving mass which define an acceleration ceiling of the piston / connecting rod and thus their maximum speed.
On a diesel the maximum speed is not limited by the moving equipment but by the duration of the combustion.

Diesel already works on the principle of self-ignition.
The chain reaction is already taking place, no need to want more compressed air diesel.

On the other hand on a fuel combustion is controlled, so we are far from the chain reaction that is self-ignition, so there is much to win.

As for the demonstration:
We assume a 1.6 atmospheric gasoline engine compressed to 10/1 whose torque value is constant from 2000 to 6000 RPM "" "unreal torque but necessary for the purposes of explanation." ""
This torque value is 15mkg
1 cubic meter of air at 40% humidity and 20 ° c = 1.2kg
stoichiometry of gasoline = mass 14.5

To climb a dimension we need to be at least 3000RPM
The power at 3000rpm is
p = (C * R) / 716 = (15 * 3000) / 716 = 62.84holes.
The volume of air drawn in is
intake cycle * displacement = (3000 / 2) * 1600 = 2400000cc / min
= 2.4 cube meter / minute
the air mass is from
2.4 * 1.2 = 2.88kg / min
the mass of gasoline injected is
2.88kgmin / 14.5 = 0.198kg / minutes


Now suppose we compress that 30% engine more.
The cut therefore amounts to 15 * 1.3 = 19.5mkg
19.5mkg on the same speed range.
We previously needed 62.84 horses to climb a rating.
the torque being constant is 30% higher, we will now calculate at what rate we get the 62.84hexes.
P = (C * R) / 716
R = (P * 716) / C = (62.84 * 716) / 19.5 = 2307RPM
The volume of air drawn in is
(2307 / 2) * 1600 = 1845600cc / min = 1.8456metecube / min
The air mass is
1.8456 * 1.2 = 2.21472kg / min
The mass of gasoline is
2.21472 / 14.5 = 0.15273kg / min

We save 0.198 / 0.15273 = 1.2964.
The fuel economy is 29.64%

Here I demonstrated the thing.
Now it only remains to learn ...
a+

[AurélienRC]

For the demonstration, would it be necessary to deduce that increasing compression actually decreases the consumption of the same value?

[iridium]

Not really.

The reasoning followed is for a constant torque value.
At constant torque, over a wide range of speeds, you find the same power as much lower in the tower as the increase of the RV.

In reality, on atmospheric gas the torque is not constant and increases when one goes up in the towers.
The equivalent power is no longer found at a lower rate of the number of% increase of the RV.
the equivalent power is thus no longer at 30% lower speed but little changed to 20 or 10% lower speed.

It all depends on the torque curve of the vehicle!

Then there are many other losses that I do not take into consideration here.
This does not change the savings potential that a system like I would offer.

Here at uvhc we won several times the marathon diesel category with 50% of km traveled in more than the second.
On my side the essence is not part of the objectives.
I find it hard to persuade to develop this system.
I hope that the pedagogical model that we have developed will attract colleagues who will want to go through the project.

In the meantime I share the idea with you.
I could not answer for a while anymore.
a + and good luck

[Other]

Hello

According to the tree has cam with different angles, the couple is differrent according to the regime.

Example two engines identical same cylinder, same piston, same compression ratio, same crankshaft (identical bore identical, even raised valves) just the tree has cam that differ.
Either the Continental O-200 engine that develops 100hp to 2750rpm and the Continental C90 engine that develops 90hp to 2575 rpm
in use the 90hp engine is significantly more advantageous, more torque has 2350rpm which is the RPM takeoff and climb.
the C90 rotates larger diameter propellers ..
In the trade the constructors poses 100hp instead of the 90 hp it remains glued on the figure 100hp versus 90hp, which the users do not know, the 100hp you will never use it if you do not manage to reach it.


In the post above it mentions to increase the compression ratio in a diesel (it is necessary to take into account the necessary energy for such a compression rate, without counting the structure of the engine)
On planes compression rates are very low it varies from 6,5 to 7,5 exceptionally to 9,7 this makes a problem engine that has to work on 100 / 130 fuel.
The reason is that an air-cooled engine, has much hotter yokes and at the end of compression the temperature of the mixture is close to the point of inflamation.

There is also the relationship between a long race a square and a super square.
most of the small Lycoming engines are super square (despite their low revolution 2750rpm) it is a question of congestion of length of connecting rod ect ..
the strokes vary of 95 mm 102mm the diameters of pistons
vary from 120mm to 135mm in large rooms you have to put two candles placed at a remote place to avoid detonation (not just for security reasons as many people think)
When we look at the evolution of the Lycoming engine we realize that often it keeps the same architecture either it magnifies the pistons with the same run the 115hp versus the 135 hp, the 150hp, or it increases the race with the same pistons, either the 150hp versus the 180hp.
In use it is noticed that there is a ratio bore stroke which is more favorable on the performance consumption.

It should be understood that the manufacturers try not to diversify the parts, to have the same pistons the same cylinders for a range of engines, to keep parts in stock over periods of 30ans.

Andre

[chatelot16]

if it was enough to increase 30% compression rate to increase 30% power without a drop of gas and more everyone would have already done!

increase the compression ratio increases the torque produced during the relaxation ... but alas also increases the torque during the compression ... there is a possible increase of yield if all is well studied ... but the manufacturers have already found the optimum for the classic engine

the optimum for the car engine is different from the airplane engine: the car engine has a wider operating range than the aircraft engine ... the aircraft engines do not have the best performance because the main goal is reliability: the complication to gain some% performance at the expense of reliability it's not for planes!

rudolf diesel made a prototype with a huge compression ratio, which had so much loss that it did not produce power!

[Flytox]

The engine speed and compression have nothing to do.
It is the materials of the moving mass which define an acceleration ceiling of the piston / connecting rod and thus their maximum speed.
On a diesel the maximum speed is not limited by the moving equipment but by the duration of the combustion.

A little bit anyway, quote me even-displacement series engines that run at the speed of a gasoline with the compression ratio of a diesel. Except some dragster made for 400 m I do not see too much ...

On a 2 time (50 cm3), when one compresses too much, he is well at low speed but he does not want to fly in the towers (even without clicking). In the end it's worse. AMHA there is a threshold from which we can not win anything or even lose.

[AurélienRC]

There are some very interesting books on it, especially at ETAI. I read some of them in the past with very interesting explanations and thermodynamic calculations on supercharging, thermodynamics, injection-ignition systems and so on.
But between us, I do not believe that we will invent anything of very relevant through these exchanges, the engineers of the various manufacturers having made a long time for the development of their engines ....
When you see that cylinder head 4 valves per cylinder exist since the beginning of the 20 century, just like the variable timing of the distribution and other things .....

[iridium]

Hello everyone,
I'm back.

increase the compression ratio increases the torque produced during the relaxation ... but alas also increases the torque during the compression ... there is a possible increase of yield if all is well studied ... but the manufacturers have already found the optimum for the classic engine

the optimum is above all reliability in all conditions for their tranquility.
An enslavement of the position of the throttle linked to high compressions, it is less reliable than a motor simply compressed to 10: 1, because the goal is to always look for the optimal compression.
the question is: what will the life expectancy !!

A little bit anyway, quote me even-displacement series engines that run at the speed of a gasoline with the compression ratio of a diesel. Except some dragster made for 400 m I do not see too much.

I repeat what I seem to have said before:
The maximum engine speed of a diesel is related to the duration of the explosion.
The diesel is slow to catch fire or a loss of torque at high speed, the combustion continues almost until PMB despite auto ignition.
This maximum engine speed on a diesel is not related to the compression of this one.
The threshold we are talking about is after self ignition, which is not the case for gasoline engines.

MAZDA to realize a compressed engine with 14: 1.
marketed in japan if my memory is good, it uses a gasoline high octane.
The assembly that I propose allows the same thing but in addition would allow the use of gasoline low octane by controlling the position of the butterfly.
In short, it makes it more flexible to use something that already exists.
The goal is to get the most out of each fuel.
which ultimately reduces the service life of the engine.
the insidious guard included in the servocontrol make it possible to define this lifetime by optimizing more or less the compression.

Here is the wiki page in English on the volumetric report.
we learn a lot more than French.

http://en.wikipedia.org/wiki/Compression_ratio

See you soon

[brenamanf]

Hi everybody !

I did not think there would be answers my subject given the answer that I could have at the beginning!

With only an answer, I turned to the realization of a simple control system of the vehicle.

I still started an arduino-based ECU, which is supposed to set the ignition timing according to engine speed, knock sensor and exhaust temperature sensor and engine temperature.

-In Secondo came the idea of ​​adding an HP water injector after the butterfly to lower the temperature in the cylinder and increase the compression.
-Then I planned to isolate the engine with rockwool and put a heat with a temperature between 100 and 110 degrees
-And finally add an MSD type system to generate several sparks

I publish and continue the adventure here:
http://brenamanf.wordpress.com/

Qty.