What you think about that? Suround injector for diesel

[MKimagin]

12 years ego I patented idea that modified the way how the fuel is injected in to combustion chamber in diesel engine.
I do not see that the potential investor tray to get thru doors and widows to get this idea in production, so here it is.

http://patft.uspto.gov/netacgi/nph-...,385,127.WKU.&OS=PN/5,385,127&RS=PN/5,385,127

What is your opinion, can it work , what the advantage what disadvantage.
Let me give you some history.
The idea start when i was teenager in med 80s I read sower that true diesel engine is when RPM is below 500. Any thing above the efficiency will go down.
I read also that big diesel engine in ships used multi injector. Then i read that trucks used injectors with multiple injection point that direct the fuel out ward from the injector.
Another idea (I think that I so that in Popular Mechanic) on the beginning of 90s was 4 independent injectors per cylinder position vertically with end tip bended 90 degree. So 4 point injection.
I said to may self , that OK but is till not enough.
So I look on the cross section of the fuel injector, and then it struck me, if you can create ring from that you could inject massive amount of fuel in very short time, and in the same time the injected fuel should create vortex that will make very constant and uniform combustion.
The idea never get really beyond the idea. So i wonder what you people think about it.

 

[globi5]

Modern diesel engines all have multipoint injection (up to 12 holes):

http://www.eng.warwick.ac.uk/oel/previous/diesel/diesel.jpg

http://www.kfztech.de/kfztechnik/motor/diesel/duesen/inlineinjektor2.jpg

The fuel is injected in the center vs. circumference (as you mentioned yourself.)
If the fuel is injected in the center onto the piston crater then you can keep the fuel mixture off the walls. This will keep the heat off the cylinder walls, improve combustion and decrease heat loss and cool the piston.
If the fuel is injected from the circumference it would be squirted (due to the extremely high fuel pressures) onto the cylinder walls (= not good). Maybe you could direct the fuel flow onto a piston cavity as well, but it would still make the whole system far more complicated. Keep in mind todays diesel engines operate at extremely high fuel pressures (2000 atm) and have highly sophisticated piezo activated valves with tiny injection holes. If you had all that in the circumference you'd need several valves per cylinder, it would be more difficult to seal, far more complicated to manufacture and of course more expensive.

 

[MKimagin]

I am very surprise that it will go to cylinder walls. The main idea was that the injected fuel come from the cylinder wall and will combust with in the gap between piston and cylinder head. Also the amount of fuel injected thru each hole should be at list 100 time smaller then in conventional injector. Something like micro combustion.

So what you saning the main trick is to inject the fuel and finalize the combustion before the mixture hit the cold walls of the cylinder. Interesting.

One of my concern always was what the size of the element should be. Winh so high pressure the surface of the injector have to very small otherwise everything will implode.
My domain is electrical engineering, so when you said "piezo activated valves" it start ringing in my head LOL.
In my solution the movement of that piezo activated valves have to be much smaller then in conventional solution. If I am correct piezo electric materials may operate better with smaller displacement then bigger.
I also expect that the shock wave generate during the injection and combustion will have much better characteristic due to even distribution of forces that act on on the outer (bigger) surfaces of the piston and cylinder head.
The piston surface as well cylinder head should be flat and probably have ceramic finish in order to reduce heat loss.

 

[globi5]

I've read that at fuel injection pressures of 2000 atm, fuel can reach 2000 km/h. If it was to burn before it reaches the opposite wall it has to evaporate and burn extremely fast. You wouldn't want to lower the pressure since higher pressure leads to smaller droplets and improves combustion.
Hitting something is not necessarily bad it helps dispersing the fuel. The way it works now is it injects the fuel onto the piston where it mainly gets dispersed after it hits the piston and ignition happens within that cavity.

http://www.kfztech.de/kfztechnik/motor/diesel/duesen/inlineinjektor2.jpg

The cavity on the piston also functions as a little combustion chamber within the combustion chamber with a lower surface to volume ratio.

You need relatively large Piezos. Current Bosch injection nozzles apparently have 350 layers of piezo ceramic layers and the entire valve only moves 0.04 mm. Making it smaller will reduce that movement.

 

[MKimagin]

There no way that the fuel will reach the opposite end of combustion chamber and hit the wall of cylinder. The reason is that the fuel injected from on side (even at that high pressure and speed) will meet the other portion of the fuel from opposite side that have similar velocity, so the forces cancel each other. I also expect that the injection points had to be position to aim sightly of center so each individual stream will impose force on one side of the other so the hole mixture should start to spin in one direction creating some kind of vortex. Because of the attack angle, the fuel will have to have tendency to disperse. That good thing.
One of the problem with high pressure is that the injected fuel portion act like balloon that expand, displacing the air potion. The surface are increasing however the portion that is in side the “balloon” do not have contact with air and have to wait utile all the outer layers will burn out or be divided . So you have to wait much longer then if you will divide the same portion in much smaller spices.

As you point out, in conventional solution it is done by hitting the cavity of in the piston. I do not believe that the fuel will start burn out in large quantity before it hit the cavity wall of the piston (the speed is to high and the area of contact between fuel and air too small).
The piston cavity improve mixing however it cool down the fuel, reducing it capability. So we have one big plus with couple small minuses.

Yes the piezo will have to be really big , basically circumference of the cylinder. Not exactly low cost solution.