Improved Efficiency / Combustion Engines Explosion

[I Citro]

I am working on another area of ​​progress, more urgent in my opinion, which is to reduce to the strictest necessary engine running time.

iridium, who knows the eco-marathon and probably the Educ-Eco Challenge, could he tell us the time to start engines during the events.
I remember being struck by the short running times at NOGARO, which I think was in the order of a minute for a lap of 3,6km (covered in just over 8 minutes).

My daily observation is that many motorists leave their engines running for nothing (during a stop at the bakery, at the tobacconist ...) and of course at traffic lights or stopped in traffic jams. This represents millions of liters of waste per day and 3 times more if we consider those spent before filling the tanks of vehicles ...

The test of a TOYOTA Hybrid convinced me of the relevance of the concept which eliminates this waste without the knowledge of the driver by being more intelligent than him, with as a bonus a recovery of energy.
The Citroën "Hybrid AIR" that I vilified on this forum is therefore an excellent product in that it eliminates these wastes that are insults to human intelligence.

So I think there is more to be gained in the transmission and management of engine running time than in improving their combustion.
That said, skills on arduino might be welcome for the implementation of my STOP & START project...
I recall here my first experience:
On 40 km traveled in 50 minutes, I managed to cut my engine for 18 minutes. either 1 / 3 of operation time removed ...

[chatelot16]

shut down the engine and put in the neutral position whenever there is no need not cost anything ... but is still prohibited on normal car

it is useless for a big flat road trip ... but very useful when there are climbs and descents

I remember at the entry of besançon of a road where the simca 1000 descended to 70km / h in neutral without touching the brake on km! neither brake nor assisted steering

with the current technique it would be possible to manage everything automatically on a normal car, for a ridiculous price ... without the need for a big battery and big electric motor like a real hybrid

an electric power steering pump is anyway more economical than a conventional pump that brews too much oil at high engine speed, to have just enough to slow down

[iridium]

the operating times are brief as you point out.
Our students climbing in their study, it is necessary to train new pilot regularly.
unlike some school that has been their appointed driver for years.
The problem lies especially in the sudden arrival of the power at the restart, one of our new driver who made a roll in a turn.

[gildas]

Hello,

Concerning the improvement-performance there is also this:

The information was not given on the web, it comes from the English magazine Auto Express, in its paper edition of 20 March. It reads p. 20 excerpts from an interview with Herbert Diess, BMW's director of development. He explains that in order to meet CO2's future emission reduction targets, petrol engines will have to be completely redesigned. Admittedly, the spark ignition engine still retains a good margin of progress, by reducing friction, particularly at the distribution level, and by increasing injection pressures. But for it to become really ultra-sober, there will be no other way than to drastically reduce the rotation regime.

We would like it to be an April Fool's joke, but unfortunately it's very serious. Mr. Diess sees the future in petrol engines whose maximum speed would be 2500 rpm. The maximum torque regime would be 800 rpm. In the longer term, with ultra long transmissions and a large number of reports, one can even imagine gasoline engines that would not run beyond 1500 rpm! The cars they will be equipped will be considerably more fuel-efficient than those that made the brand's reputation, and those who drive them will be delighted by their greatly reduced CO2 emissions. But it will take more than that to not have the nostalgia of old models.

http://www.moteurnature.com/actu/uneact ... s_id=26908

Applying this technique (slow-load regime) on diesel engine + water doping would give very good results in fuel economy ...

[Christophe]

Yes gildas!

If not surprising way of research at BMW ...

Decreasing the RPM for the same torque / power necessarily means increasing the engine capacity ... or making hyperbaric or ultra turbocharged engines! No?

In 3 cases it's not won!

[gildas]

Decreasing the RPM for the same torque / power necessarily means increasing the engine capacity ... or making hyperbaric or ultra turbocharged engines! No?

I leave this question to the specialists.
However, greatly increasing the pressure in an engine makes this disadvantage appear:

Likewise, increasing the effective average pressure (PME) too much can lead to increased piston / liner friction.

In short, it's complicated, and a simple rule: full load half-speed = the best engine performance.

https://www.econologie.com/forums/ameliorati ... 56-20.html

Hey, hey, but here too the friction can be mitigated by the water doping which gives a more uniform pressure on the piston ...

[chatelot16]

to advance, it is necessary to have real data on the operation of a motor: for example recording of the pressure in the cylinder during a lap

alas everyone knows only what is given in the old technology book ... never updated with actual data current engine

ditto for thermodynamics courses at the university: we did theoretical cycle calculations to compare gasoline engine and diesel engine based on simplistic assumptions giving results that are caricature!

it's been a long time since I read between the lines of everything I find, and the reality is very subtle

the current car engines are at the optimum in the context where they are, to do better we must get out of the box

for example for the gasoline engine, the efficiency is bad at low power ... which miserably reduces the economy that can be done by raising the foot: one solution is not to explode the cylinder all around, but to voluntarily miss cycles: instead of always having a partial load, having just a certain number of times an optimum load and other times nothing at all! this solution requires to have a heavier flywheel to accept a more irregular couple ... must also accept a strange noise

with the gasoline engine that has an injector in front of each valve, this sequential charging system would cost almost nothing, and give gasoline the main advantage of diesel: low load efficiency as good as hot

when it pee less often it heats less: we could take advantage to increase compression ... but when we see the actual pressure curve in a gasoline engine, we see that it is useless to change the compression ratio: it simply increase the advance on ignition to do the same effect: the programmer also to increase the advance when it reduces the number of explosion costs nothing

another way citro speaks in another subject, cause the complete stop of the engine and the deadlock whenever it is useless: and on certain road it is quite important
https://www.econologie.com/forums/post259646.html#259646

that too would not cost anything if it was done well by a manufacturer ... but currently it is forbidden by the highway code to do it on a regular car ...

also we must go out of the box to improve

[I Citro]

I did not know (or I forgot) this prohibition of the highway code to shut down the engine.

It's funny to see that hybrid vehicles do it by design.

Regarding the reduction of engine rotation, I am convinced that it allows to better exploit the driving force that they produce at each explosion because we increase the time during which we use the fuel injected into the cylinder.

The limit remains the appearance too sensitive acyclisms and rattling generated under heavy load.

From this point of view, I consider that engines powered by LPG would be more efficient if they were developed around a diesel engine (lower engine speed and higher compression).
But the initial approach prevailing in the use of LPG was not the yield but the tax saving ...

[chatelot16]

to run a motor at low speed and high torque, it is not only the engine that counts, there is especially the rigidity of the transmission: and the transverse mounted motor are much worse than the longitudinal mounted motor: why ? because with a longitudinal motor its fixing and easily flexible enough to let the motor move in the sense that it vibrates, and rigid in the direction it is necessary to transmit the torque to the wheel

with the transversal motor the flexibility in the direction of the vibration of the motor is directly flexible in the transmission: compromise difficult to find

a transverse engine loses power in its suspension system

I did tests of intermittent operation of the cylinder on the GS, it supported very well the irregularity of the couple ... on a current transversal engine is harder

[iridium]

with the gasoline engine that has an injector in front of each valve, this sequential charging system would cost almost nothing, and give gasoline the main advantage of diesel: low load efficiency as good as hot

it would be difficult to start at a red light given the difference in torque between a petrol and diesel engine.
difference in torque due to the difference in compression between diesel and gasoline!
+ of compression = + of temperature = + of propagation speed = + of SME


I have trouble imagining a gasoline engine that would provide maximum torque at the idle speed of a current gasoline.
big flywheel for smoothed the operation of a motor that would surely be a 4 cyl or less.
very big engine or supercharging very important.
in short we come back to the problem of rattling and auto-ignition.

it will be simpler to adapt the fuel to the future vehicle.

Regarding the reduction of engine rotation, I am convinced that it allows to better exploit the driving force that they produce at each explosion because we increase the time during which we use the fuel injected into the cylinder.

see the studies made on the flame front "propagation speed".
we know that on diesel increased engine speed is a pure loss.
on a gasoline the complete combustion before the PMB can proceed up to higher property regimes.
I meet you about LPG and I would even add city gas or even pure methane.