axial supercharger amazing!
 

http://www.s2ki.com/forums/index.php...ic=266584&st=0

this boggles me

cool.

I work for an aircraft engine company. I highly doubt this would ever work for any sort of practical application. As someone in that thread posted, the power band would be really limited because of the off-design characteristics of most of daily driving. Things might be differenct for drag racing though, since you would mostly have high RPMs and be in the "sweet spot" for the compressor.

It's cool to see this since that's the kind of stuff I work on daily. Props to them if they get it to work. I'd sure like to see it.

Seems to be best suited for low pressure applications (e.g. 6-8psi) for reasons of practicality. Possibly a viable option for high compression, normally aspirated engines. The concept of using axial superchargers for piston engines however has been around a very, very long time.

Pictures (and a ridiculous amount of information) can be found here:

http://www.rx8club.com/showthread.php?t=29778

It looks really cool, though I would obviously want to stick with the turbo on my car. It would be neat for the right application, which probably would be the RX-8.

how much of the thread did you guys read? this guy has been around for a long time, he was workin' wtih them since the 60s. now we have all this cnc stuff and it's more practical to produce.

these wouldn't just work for low boost and if you read the thread it's not really the boost that's significant. i mean you can say this for any forced induction system but we're used to seeing similar (bad) efficiencies between centrifugal, twin screw, lobes type superchargers. this things can move as much air mass as you want just by adding more stages.

if you look at the pictures later on you'll see it's "adjustable" you can add stages very easily.

i mean these things work on jets that move tens if not hundreds of thousands of cfm... that was the example used, there's no problem designing something within the confines of the engine bay that can move about 2000cfm.

i'm not sure about the off design boost characteristics that everyone keeps bringing up because technically all compressors are idealized for one specific band of power, it's just nature. but apparently by the hard data that's available in the rx8 section of the discussion there's a very linear power curve and matches if not beats a lobes type.

the other interesting topic brought up is the gasoline injection before the charger which boost thermal efficiency by a lot. the blades easily atomize the fuel...

also i don't know if you guys caught that this unit is placed AFTER the throttle body, that means no bovs and stuff like that... AND most important there's almost no drag force at off throttle situations becuase the compressor is put in a vacuum and it hardly compresses any air.

Axial compressors are, as stated, suited for a specific RPM. Try to run it too fast and the blades will stall out and cause damage. You'd need something similar to the bleed-air valves on a turbo-prop compressor such as the T56A-7 or -15 engines on a C-130. Axial flow turbines only create so much pressure so the power is actually regulated by how much fuel you throw in. That is the reason you need to carefuly watch EGT or Turbine Inlet Temperature. The air coming from the compressor mixed with too much gas can easily destroy turbine blades if not carefully monitored.

that is such a basic engineering problem don't you think he would have had that sorted? peak boost is at peak rpm... it will never run past that and cause stall or supersonic shockwave.

and i'm not fully understanding what your second point is.

I didn't say anything about peak boost at peak RPM. I said an axial compressor is designed to run at one specific RPM to achieve maximum effeciency. I wasn't disputing anything written by this guy so kindly get your foot out of my ass and chill bro.

And the second point (which wasn't a point) was just basic information about how axials compressors work.

I spent an hour reading the threads. The axial compressor is VERY good thing. The one he is using in the kits for rx8/s2000 are 650 cfm 4 stage units at just 8psi. A 20g is rated at 650cfm at 15psi. A turbo is 65% efficient. The axial compressor is 85% efficient. These compressors have tremendous potential. All you have to do is add stages to get more flow. He built a 7 stage compressor that flowed 1800cfm at 17psi. I have never been a fan of supercharges. but these things may someday outperform turbos in the right hands.

dude... what did i say that was offensive? i just said it's a basic engineering problem and it's already well sorted. who needs to chill?

you actually stated axial turbines, and i don't dispute at all the validity of the statement. what i was wondering is why you even mentioned it. this is not a turbine.... this is a compressor. so you wouldn't have to watch the egts because this would be an intake temperature type thing... and the intake temperatures would be going down with more fuel....

so i don't see why you're so pissed off.... but yeah....................... i have to wonder...

My bad...poor proofreading. I mean to say "compressors". And as I said before I was just throwing out some basic knowledge about how the compressors work in aircraft sized applications.