Yeah, I realize that. After reading what you posted I started having another thought about velocity stacks, and maybe some modifications to make them even better than they already are.

Again, this is just a random thought, but what if we could design a way to make, say a velocity stack styled intake tube, with the funneled end on it. (Here is the tricky part) Add to it a way to make the intake tube thinner in diameter at low rpm's and larger at higher rpm's. I suppose the other way would be to make it variable length wise. Jamming more air into the compressor side of the turbo than normal.

What sparked this thought, in combination with the above post, was that in the Group N, WRC, turbos that used restrictors to limit the amount of airflow the turbo could receive. Initially, the turbo achieved an over speed condition, which caused the wheels to spin beyond the limits of the prescribed compressor map ect... To fix this, an increase in the height of the cold side wheel was shown to eliminate the over speed.

... but it was the narrowing of the restrictor that accelerated the air in the first place, which is what could be used to enhance the airflow into a turbo.

I dunno, maybe make it out of some material the collapses slightly, as suction is applied.

...It also kinda has some of the ideas from a scram jet without the fuel spark thing. no ? ... ehh, maybe not. ...ok now you go.

 

I used to own the experimental validation of F100-PW-229s as well as a few others.

Now I work for GE designing large frame gas turbine compressor airfoils.

I have some pics of said combustion chamber right here, but alas, my daughter is crying and I have to go feed her. I'll post more later.

 

Nope. The SR71 engine, the mightly J58 is a phenominal engine for its time, and still is. It is a turbojet engine. The thing that made the engine able to still generate thrust at high Mach speeds is the nose cone. It was telescopic, and depending on the airspeed, it would traverse out to keep the shockwaves from entering the engine. Elsewise, it is a normal turbojet engine.

 

Constriction in a tube increases velocity, and decreases pressure, thus not acting like a compressor. In a constant diameter tube, you can only accelerate the airflow up to Mach 1.0, after than the flow is choked, and you need a diverging nozzle to accelerate the Mach 1.0 flow to supersonic speeds. Fanno flow 101.

 

Nope. It doesn't compress the air further directly in the stacks (again, fanno flow). Velocity stacks are to do just that, inclease the velocity of the airflow into the - either intake, carburator, or the turbo - essentially allowing more air mass to enter.

 

One problem with trying to do something like this on the intake air is that you will have already used up all the available O2 before it gets to the engine. At that point you are better off just using a turbine engine like a helicopter does because the reciprocating piston engine won't be getting any useful air.

-Paul

 

I stumbled across this thread and found it interesting.
Remember what a Buzz Bomb was? It used flaps that would open upon suction, and a timed event combustion would then explode inside the chamber, causing the flaps to close and provide thrust. When the fuel ran out, scavenging would occur and draw the flaps open again by vacuum.

Im not sure how this could be put into effect to aid spool time...but its cool technology, despite its grim usage.


I actually was checking out the first 4 cylinder Top Fuel dragster....and I was thinking, instead of the ram/scram jet idea, there is a possibility to use an anti lag system like this guy used...

Basically, he sprayed nitrous right into the turbo manifold, aiding spool. Never saw it done before, just into the engine to aid spool, not into the manifold.