Turbo Charging Gas Engines ?

How was this 2 stage water injection done ?

 

I had a conversation with a Physics professor over water injection.
He says the Technology isnt up to the task just yet.

When I lived in Alaska I realized some of what he was talking about.

 

Water Injection

thudpucker and kistinie,

There is little technology involved in the water injection I'm referring to.

A little methyl hydrate would solve the Alaska issue.

Two stage in that two intake manifold pressure sensors would activate two

windshield washer bottle/pumps. One at three pounds and the other at

nine. The injectors were low grade bolts drilled out and simply bolted to

the air cleaner cover. They were offset ever so slightly from centre so

the water squirted directly onto the impeller. The first stage jet was

smaller in diameter than the second. In retrospect, a third may not have

been a bad idea but I never expected the self limiting system to develop

so much boost. It all worked so I didn't "fix" it. I didn't hear any

detonation but that doesn't mean it wasn't happening of course. Although,

when I tore the engine down years later, there were no signs of it. The

compression chambers were amazingly clean from all the steam cleaning

they had received.

Again, I agree with the previous post that marine use of turbos isn't nearly

as advantagious with gas engines unless it is a light weight, high

performance boat where weight is an issue. Even then, a turbo diesel

would be a better way to go. More torque and better suited to turbo'ing.

Tom

 

If I remember right when water changes to steam it expands (or tries to) by 17,000 times. So just a little drop of water could make quite a pressure difference in the combustion chamber.

Wasn't there a WWII aircraft that made use of this supercharging method??

 

For a while I used the same setup with windshield washer bottles as described above on an '85 GN. Believe it or not I found that the water droplets were eroding the turbo impeller! If you've ever seen what rain does to helicopter main rotor blades (the ones that use Al leading edges, like the Bell 206) then this is not so far fetched. I observed this on two different impellers. There were very good air filters upstream, so no other explanation.

Jimbo

 

Now the thread is getting interesting.
On FLoat plane's the Props suffer badly from water droplets. Like those Choppper blades.
Tom's description of what he did is new to me. I tried to draw it on paper to better understand it. It sure sounds like it worked for him

On that WWII plane using water injection. They tried that in a number of applications. War time engines dont care about water damage. They are expendable. I think just about everything they tried in WWII was never used again except for Exhaust powerd Turbo Charging.

The professor talking to me about water was referring to the chemical damages water did to some parts of a Gasoline combustion engine. This was in the early 60's though, so things may have improved since then.

Steam is so much more powerful than Gas or Oil because it expands so much more. However its not as quick so the guys who really want action dont mess around with steam. However, too much steam in a small combustion chamber could be a bad thing if you let it mature.

If a boat was powerd with an older, long stroke, low combustion engine. That little bit of water in the slow turning engine might just make a noticable difference without killing anything.
Turbo charging one of those old slow luggers might help too, but increasing the Rpm's seems like a crime to me.

Logically thinking, if your going to those lengths to get more power, change engines for a bigger Capacity.

 

Jimbo, what if you injected the water after the Turbo?
Would that would work?

 

Yeah it would and did. But then you have to atomize it properly, and there are also potential distribution issues, even injecting right after the turbo. Sending it through the turbo impeller micro atomizes and homogenizes it. Too bad about the erosion, huh?

My next setup used a in-tank EFI style fuel pump to pump the water (at high pressure) through atomizing nozzles downstream of the turbo. Problem solved, but it neccessarily gets much more complex to do one of these setups right.

Jimbo

 

Your right on it. I used to fool around with the porting Bike engines, and oneday I had the chance encounter with an Engineer from HarleyDavidson.

Boy did I learn a lot about induction and the real tricks to 'atomizing' so you present a thoroughly emulsified mix to the compression chamber, and then shape the compressioin chamber so that mix dont re-combine or solidify as it swirls into the chamber and slams into walls of metal and thermal walls from the previous combustion gasses left in the combustion chamber, which are still expanding....They actually have Cameras to get photos and movies of this happening. Amazing eh?

As you can imagine, I was kinda thrilled and overwhelmed at the same time.
One thing that conversation taught me is that a very well funded and equipped R&D lab is an ablolute necessity when your are going for the gusto!!

One of the things he mentioned was not to polish the intake walls. The roughness of the walls helps.
The smoothness actually causes a thick hard layer of static air to develop and stick, slow down, which grows, choking down the size of the tube, and actually inhibits high speed induction. Whodathunkit?

 

The BOSCH Mechanical FI used on the VW Rabbit has a similer product to your idea. As soon as the Induction starts, a switch tied to a flap in the induction port causes a pump to start up and the injectors start spraying under hi pressure. I liked that setup. Simple and it worked good with good Mpg. The only problem was the filters just couldnt keep the fuel clean and plugging the injectors was an expensive problem.
Keep that in mind as you hi-pressure your water spray.

 

I don't think he meant injecting the water into 'turbo impeller'. I wouldn't think that was such a good idea. Besides why do you need the turbo unit when you get the sought after pressure by the water expansion?

 

Brian, I dont know this for certain, but I think the water would never heat up and turn to steam fast enough to be usable if it werent pre-heated before it hit the compression chamber.

We'd need the 212 Degrees long before the water passed the intake port in the head.
Water takes longer to expand than Gasoline. So if it were suddenly heated to 1100 degrees in the compression chamber, it would be expanding rapidly but as it did, it would also be passing out the exhaust port. Too late to help with moving the piston.
The Gasoline piston speed is so much greater than a Steam engine piston speed.

I think we'd want to pass the water spray over a heated electrode so it was nearly steam as it entered the in-flow through the Intake valve.

Without a lab to test this theory, I'd really be guessing in the dark.

 

Plenty of preheat available right at exhaust pipes, particularly for such a small amount of water actually injected..... I would think?

What did those Spitfire aircraft do? I think it was used on them...one of those WWll fighter aircraft?

..one reference
http://blizzard.rwic.und.edu/~nordlie/water_injection/background.html

 

http://www.chuckhawks.com/best_fighter_planes.htm

The final Messerschmitt production variant was the "K," deliveries of which began in September of 1944. The "K" was powered by an 1,800 hp DB 605D engine (2000 hp with methanol-water injection) that gave it a top speed of 452 m.p.h. at 19,685 feet. Best climb rate was a sensational 4,820 ft./min. Armament was two 13mm cowl mounted machine guns and one engine mounted 30mm cannon firing through the propeller boss. Two additional 20mm cannons were mounted beneath the wings in the K-4/R4 variant.



The final major production version of the Mustang was the P-51H. This re-designed model incorporated major improvements, as extensive in scope as those incorporated into the FW 190D or Spitfire Mk. 22.

In the H model, the structure was increased in strength by 10%, to allow higher "g" loads in combat maneuvers. No structural part was left in common with earlier models. Streamlining was improved to increase speed, and stability was increased. A new version of the Packard/Merlin, incorporating water injection, delivered over 2000 hp. These changes resulted in the finest American fighter of the war. Speed was 486 m.p.h. at 30,000 ft. best climb rate was 5,350 ft./min. at 5,000 ft. Service ceiling was 41,600 ft.

 

The water injection was used to prevent detonation