Ok, I know all there is to know about the Pratt & Whitney Turbine engine, they have them on the C17's that I work on. I was looking at how the jet engine compresses air, and some of the methods used by turbochargers and superchargers to compress air, there arent many different types of turbochargers but there are a few more supercharger designs. I wanted to know if there is anyone in here that has tryed to make/design a supercharger that is the same design as the compressor section on a Turbine jet engine? If you took the compressor section off of the front of a turbine engine, shrunk it down, put a shaft through the middle of it to drive it, put a pully at the end of it and hooked it to the engine with a belt, you would also have to have a turbo cooler for the air, because it will get hot.

The only thing that they dont show is the Stators, in a turbofan engine there are rotors and stators, the rotors are what spins, they look like fan blades, the stators are stationary, and facing the opisite direction.

Rotor = / = rotates with shaft.
Stator= \ =does not move.

If you have them in a series it looks like this-

\ / \ /
\ / \ /
\ / \ /
\ / \ /
\ / \ /
The more rotors and stators you have the more stages of compresion, Also the main key to the compresion is the cone in the middle, it is what all of the blades (rotors and stators) are connected to. At the beguining of the stages of compression,the cone is small, (the tip), as you go further back the cone gets larger, and the air gets more compressed, and since the fan blades are pushing the air towards the large end of the cone it has no where to go so it compresses as much as it can.
For thoes of you who dont understand this might help.
http://travel.howstuffworks.com/turbine3.htm

I was just thinking about this so if anyone has any imput on it that would be great, I am in the process of designing somthing. I will get back to you with the progress and test results, I am using computer fan blades, and PVC pipe, if you have a beter idea let me know.

 

bumpidy

 

(How to make a supercharger cost $21,000...)

What you're talking about is an axial flow compressor. The compressor part of a turbocharger is a radial flow (actually mixed-flow) compressor. That's probably more compact & cheaper, & more effective for a car. But most superchargers are more like positive-displacement pumps, although that's sorta misleading 'cause air is compressible.

Early jet engines (Whittle, Junkers) used radial flow compressors, but when they started to get bigger & more powerful, they had to give up the advantage of 'centrifugal force', in favor of a skinnier design. You probably know all about how critical the tip clearances are, but in the USAF maybe you never knew how expensive that stuff is??

 

Oh i understand how expencive that is, Its just a concept, I have been working on it for about a year now, and now is the first time I found anyone that actualy knows what I am talking about.

I finished it the day I posted (Bumpidy), it works, it costed me 340$ that is just to make the compressor section, The tip clearances were not a problem, the first 2 stages I used plastic computer fans, and wasnt very worried about clearances, for the main compressor section I went to a airfield junkyard and found the smallest APU I could find, the rated RPM on the APU I used was 37,000, I took out the compressor section, the guy charged me 150$ for it...I used a vacuum motor to drive it, and to test how much PSI I could get out of it, I still havent tested the operation at the different RMP ranges, all I know is that it puts out a constant 4 PSI at 4000 RPM and 6 PSI at 7800 RPM, I need to find a way to control the output without blowing it up or puting too much backpresure on the blades, because the motor I am testing with is almost toast, it wants to spin faster, but I havent goten that far yet.... Everything is in perfect balance and does not even shimmy when I had it at 7800 RPM, I work at Flex-a-Lite (cooling company) and used there balancing machine befor I hooked the motor up to it, it spun it at 10,000 RPM for 20 minuites and it was all fine, very warm, but fine...I was checking out electrical superchargers on the internet, and they dont put out 1/2 as much boost as mine does? I am guessing its just a different design? Also the ones on the internet spin at 24,000 RPM ! I am currently working on welding together a bracket and geting together a gear ratio that will spin this thing to make a constant RPM while the engine is makeing a different RPM= so it pushes a constant PSI, not 2-9 PSI.

I have also been working on a one way air valve for the intake system, that way I can hook it up to the stock/aftermarket intake tube that way when its not in use, or if the engine needs more air than the charger can push it will breath through the stock intake and filter.... So far all I have is what resembels a big air valve for a blow up beach ball, just like a door with a spring. I will post the results when I hook it to my car (after I fab up some brackets to mount it to the belt) I am also using some crappy roller skate bearings for the shaft to mount to the bracket, if you have any ideas on somthing beter let me know.... Because I have a feeling they were not ment to spin at over 4000 RPM..... My design has 4 stages of compression, its 16" long and 8" in diameter. It would fit perfectly below the Intake manifold with some small modifications to the brake lines and other fluid lines.... As far as cooling, I havent goten that far yet, I am thinking about making a high flow air Cooler at work, somthing that can handle high pressure....

Please give me your opinions.

 

Building something like that with junkyard parts sounds pretty cool, takes some ingenuity... But I figured your original question was about why some company isn't doing it. I bet the real (new) cost of that APU compressor section was a lot more than $150.

The plastic computer fan for the first stages sounds kinda wimpy to me. Be careful it doesn't come apart in real-life use.

You measured 4 or 6 psi, but I'm guessing that's dead-headed (iow, zero flow rate). What you'll want to do is measure how much pressure it can make WHILE it's delivering over 200 CFM. (2.0 liter, 6000 rpm.) That's exactly why those electric superchargers are such a joke.

 

hmmm...... I took off the first stage and tested it, same readings, I am keeping it off, it was kinda worrying me anyways... I took apart an old vacuum and I am using the bearings out of that for the shaft suport, I have all my brackets welded and ready to mount, now I need a longer belt and some hose, I will keep this up to date, i will also see if I cant borrow a camera.

 

Update, It works! Kinda......Sorta, ,,, not really well... From the RPM ranges 750-2400 it does not work at all and makes me slow as a snail, the engine wants to suck so hard it almost pinches the hose I have shut, so I had the idea of installing a spring inside, like a radiator hose,,,,, That worked, but still needs more air at the low low RPM's it hardly idles, I had my idle set at 1000, and installed the charger, and it went down to 750, (normal) I tryed to up the idle and it would just bog back down, so I took it off reset it to 750 without the charger, hooked it up and the car wouldnt start... Shit,. I took it off reset it to 1000 put it on, started and bogged down to 750.... So I said the hell with it, gave it some gas, slowly revs up, if I hold the throttle all the way open in neutral, it takes about 3 seconds to get to 2500 RPM, after that I think the moving air just pushes the blades faster than the belt can turn the shaft, I have a one waybearing race, so it cant go backwards, (kinda like a sprocket) and I can hear it click when I get over 2000 RPM and that means the belt is not doing anything... I drove it and it has major torque from 3000-7100, and then the rev limiter kicks in,,,,, so its not a total failure, i just wont be using it anymore..... I like my engine and dont want to blow it up today...... Also, I have been thinking about the 'centrifugal force' charger that you were talking about, I took apart an old industrial vacuum cleaner we had in the basement for like 10 years, I took out the motor and checked it out and the only difference between this and a turbocharger, is the snail shell look for the case, I am thinking about hooking this to my intake, just to see what it does, hell even if it gives me an extra 5 HP, thats fine with me, it was free! Actualy I need a power converter.

 

damn buddy you thought about this im happy to hear it held up during testing i think ull figure it uot cause ur determined

 

I figurd it out alright, and I have a patent on it! I am partners with (cant say) custom electric blower/fan company, and we designed somthing that has been tested and works, and costs under $1000.00, it is a blower that creates 2-20 PSI, runs off of a 12VDC-120VAC converter it can handle up to 140F air temp's and is compact. It will be hiting the market next year. I have it on my car now and it rocks, the only things I was missing last time was a speed controler (which is hooked to the Throttle positioning sensor) and presure switch... We hav eyet to test its durability for 100,000 miles, but I have a feeling it will do fine, it increased my HP by 86, and thats not at full PSI. Its better than a turbocharger because of the underhood tempuratures, and there is no need for a air cooler. Also in case the motor fails, the air filter gets cloged, or the engine needs more air then the motor can supply, it has a butterfly valve that opens up on the intake tube to allow airflow so it doesent stall the engine. I have mine running off of a 2nd battery installed in my trunk, only because I have an upgraded ignition system.

 

man that rocks! I need some more info on that supercharger! Is it really just a vaccum motor? E mail me with some specs, thanks.