Another new engine

[FAST FRED]

http://www.scuderiengines.com/

Although it has been hanging around since 06 ,at least this unit is in the prototype stage .

Great claims , as usual.

I believe IF it were practical and useful the Chinese would be producing it today as the patent filing is open to anyone ,and the Chinese do not believe in copyright or patents.

FF

[Easy Rider]

Very interesting FF. Basically a reciprocating supercharged engine. I think there was a Motorcycle in the 50s and 60s that was of this basic configuration from eastern Europe (Checoslovakia (SP ?)) I think. Was a 250cc single (combustion) cylinder w a smaller compression cyl behind it. Brand name Puch. You could buy one at Sears in the early 60s. I see lots of heat loss in this engine and being a heat engine ....????

[thudpucker]

Using two cylinders as pumps, and two as Combustion/drivers is sort of a waste. A super charger or Turbo Charger would get them all four Cyliders as power producers.

[yipster]

may be so but still nice to see tho

[Adler]

The question is what happened with lost kinetic energy of the exhaust gases ?

On the Turbo-charged engines the efficiency increases because the blower side turbine absorbs the kinetic energy of the Exhaust gasses and through the coaxial air pressure wheel increases the Air flow and the Pressure to intake manifold of the engine.
This cycle is applied to use a part of the thermal lost energy regarding to increase the Cylinder's ability for burning more fuel per stroke.

In case of referred engine the exhaust gases and their kinetic energy are not used anywhere.....and so the efficiency of the engine remains the same as a natural aspiration engine.....of course the performance is increased and the consumption also and the good level of emissions (NOx) are coming through the high exhaust flow rate.....

[thudpucker]

Adler, is the use of the Exhaust gas's the advantage of the Turbo Charger (Sea Level to 5000')
Do the Engineers feel the usage of the Exhaust gas pressure as a means to provide extra atmospheres to the combustion chambers, as more efficient than a normally aspirated engine?

[TeddyDiver]

To some point yes.. The biggest advantage of a charger (any charger) comes with the fact that the combustion ratio of the cylinders of the diesel engine can be lower and still get somewhat higher pressure in the chamber. Higher pressure means better effiency. Lower mechanical combustion ratio means cheaper and more reliable engine..

[Adler]

Dear Thudpucker,

The basic matter that the engineers negotiated last 70 years regarding the mechanical efficiency of diesel engines was to reduce the kinetic energy of the exhaust gases and the strong related to that Thermal Load (measured indirectly as exhaust gases Temperature).

The Thermal load is the main representative of the Energy losses and if they were able to reduce that is obvious that they could increased the Mechanical efficiency of the engine.

If now we want to be down to earth, we can say that for example:

A V12 cyl. engine with stroke/cyl.dia 150mm/150mm has a Power performance at 450 hp /1800 rpm and needs for that an injected fuel volume per cyl./stroke 195mm³. This amount of fuel at this engine's speed produces exhaust gases at 490°C.

We try the same engine , we add a super-charger device and we increase the the injected fuel volume per cyl./stroke at 350mm³.
We measure the power at test bench and we observe that reaches to 985 hp / 1800rpm.
Finally we take a measure of Exhaust gases temperature and we find it at 360°C.

Now, what we can see?
Same Cylinder able to absorb more fuel volume per stroke (less than double), without smoking (means perfect burning) produces more Power (more than double) at the same speed (1800rpm)and the Exhaust gases Temperature is less about 130°C.

That means we have increased the mechanical efficiency of he engine.
Less fuel for more power with lower Exhaust Gases Temp.... what else?

[thudpucker]

Spoken like a true scientist Adler.
If I'm grasping the idea, the amount of EGT being Higher means the engine is wasting too much heat energy going out the exhaust.

So by incresing the atmospheres, the same engine burns better, realeasing less heat at the Exhaust and at the same time incresing the internal Combustion pressures.
Dont laugh at me if I got that wrong, just get me right!

[Adler]

Dear Thudpucker,

If we see the burning of a cylinder from the "Energy" point of view we can recognize:

The chemical Burning of the Fuel which is providing energy with two forms:
a. Mechanical applied by pressure to the piston produces torque to the crankshaft.
b. Thermal recognized by Temperature that a part is consumed to the engine's block and mainly exerted with the exhaust gases to the exit.

It is well known that the speed of every chemical reaction - like the fuel burning - is accelerated when is affected from the following condition factors:

1. Temperature of the environment.
2. Pressure of the environment.
3. Molarity of the chemical components ( concentration of fuel and oxygen)
4. Chemical Catalyst ( which here is not existed).

In our case the temperature of the environment will be equalized after 10 or 15 minutes of operation with the cooling circuit of the engine and the pressure of the environment is standard as the cylinder has constant stroke.
But the molarity could be changed.

The way to success has two directions:
First to increase the fuel quantity which is easy by increasing the fuel pump stroke.
Second to increase the Oxygen quantity and that is difficult because you need to increase the density of the intake air. That could be happened if you increase the pressure of the Intake air - but you need energy to pressurize the Air.
This amount of energy is unexploited to the exhaust gases. We add the turbocharger Device that absorbs this energy and transform it regarding to increase the Air Pressure on the Cylinder Aspiration. The gases after this exploitation run to the exit with less energy thermal and kinetic.

Here is the reason that the Temp Sensor measures lower EGT.
But that fact, when the faster combustion is exceeded, the combustion gases' Pressure is increased and is the same to say also, the Mechanical Efficiency of the Cylinder because that happened mainly from the increment of Oxygen molarity.

Finally it is important to be noted that a turbocharged engine has higher Break HP from a natural aspiration Engine even the same fuel volume per stroke injected to the cylinder.
We have to understand that the Turbocharged engine has better fuel combustion management.

[thudpucker]

What an interesting discussion. I'll have to read this again later on this evening. I'm not smart enough to get all that the first time through.

You mentioned Oxygen would be a help.
Oxygen, was Mfg on the Sub by reducing the Atmospheric pressure to Zero, running water through the unit and Oxygen boiled off, was captured and the Crew breathed it.

So could we make a similar Oxygen Generator for our Hypothetical Diesel to get a higher Combustion efficency?

[CDK]

Originally Posted by thudpucker

Using two cylinders as pumps, and two as Combustion/drivers is sort of a waste. A super charger or Turbo Charger would get them all four Cyliders as power producers.

Exactly that is probably the reason why the Scuderi brothers have spent the family fortune on patents all over the world but nobody is willing to produce the engine.

Yet there is one interesting aspect about the concept.
The pump cylinders/pistons have no thermal load so can be of a very simple design and probably do not cost much more than a Garrett turbine. When going downhill or decelerating they store energy in an air tank instead of letting the brakes convert it to heat. The compressed air can be used for propulsion directly or as a booster for the combustion cylinders. But the extra cylinders and the tank would make a car rather bulky. In a light truck it might work though.

[powerabout]

if you want to make an efficient engine just make parts that dont need a cooling system

[thudpucker]

Originally Posted by powerabout

if you want to make an efficient engine just make parts that dont need a cooling system

One of my Hi School Chums went to work for NASA on that very project. Not something we can accomplish just yet!