1logote

Saw this in Hot Rod Mag. Ive studied jet engine design some in school and this seems like a really good idea. Not sure about cost effectiveness but really damn cool. What do y'all think?


http://www.axialflow.com/products.htm

slow67

iTrader: (2)

They won't be cheap, because I'm pretty sure they are made to order, not sitting on a shelf.

twinturbo496

iTrader: (2)

I suck at using the interweb, the link provided didn't seem to show any compressor maps, but more than likely it was there, and I just couldn't see it.

From a pv=nrt standpoint, superchargers, turbo chargers, screw compressors all have some room for improvement, but I believe most often the gains are slight incremental improvements to existing basic designs, I also believe it is uncommon for anyone to make a significant improvement to the overall efficiency of mass produced units without huge investments in engineering and testing (read: big *** company spends a huge amount of $ for a measurable and repeatable improvement. For example: Eaton TVS rotors)

How many sets of TVS rotors does Eaton need to produce & sell to recover the cost of development? I suspect it is a huge number, perhaps 100K sets of rotors or more just to break even.

Thermal growth, rotor tip clearance, ambient air temp, coolant temp, pressure ratio, maximum input rpm, production tolerances, contamination, bearing life, service live, resonant frequency, torsional vibration, rotor flex, belt life... blah blah blah all that crap plus Price Point contribute to a mass production units overall efficiency.

Just my $.02 but one hand built unit tested one time doesn't mean that it will actually work when you bolt it on your engine. I think Dragon Superchargers are possibly a good example of the problem...

BadgeZ28

iTrader: (28)

In general terms our motors would require something able to flow 1200 cfm or more.

1logote

Well Im sure this isnt general knowledge but in the basic design of this the engine only turns the first compressor rotor/stator set and the the next consecutive rotor/stator sets are free and only spun up to rpm by the output of the rotor/stator set in front of it. So its similar to the turbo systems where a smaller turbo is used to spin up a larger turbo down the line except its crank driven. So in this case the only drag on the engine is that of one or two compressor rotor sets. I would imagine there is very little parasitic loss. Seems very legit from what i have read. But I imagine the cost is phenomenal. One of these built to have an output of 1200-1500 cfm would be awesome if not only for the bragging rights and coffee discussions.

1logote

I just spoke to a local A&P (airframe and powerplant technician) and he informed me that even though the tolerances are very very tight, there is no actual metal to metal contact in axial flow compressors; even with heat expansion. Even less drag, wear, and higher efficiency.

slow67

iTrader: (2)

Actually the motor turns all of the rotors, but all of the stators are stationary.

I think this company has already done all the R&D (they started making the blowers about 40 years ago) but just scale it for the application.

One downfall of Axial flow compressors, is their surge line goes farther to the right much more than centrifugal (as the P/R goes up).

1logote

Hmmm well if all the rotors are crank driven then it may not have as much potential as I originally thought.

slow67

iTrader: (2)

They are still probably the most efficient supercharger, if it wasn't they wouldn't put Axial compressors on jet engines. Only downfall to Axial supercharging is it takes more stages than a centrifugal to get to the desired P/R.

89ROC-Z

iTrader: (11)

old design....CaseIH had the axial flow rotor years ago haha

chance575

very old design, from their history page

The first use of axial flow compressors for automotive supercharging was by Norman Latham Of West Palm Beach Florida in 1956. This unit was known as the Latham Supercharger and was sold until 1965. These were built with a sheet-metal blade installed into a ring and locked by another ring. Very clever way of getting a wing into a disk. Trouble was there was no aerodynamic shape and the time to build was totally unacceptable.

1logote

Yes I think these are just very kool. I would love to see one where most of the rotors are free spinning. I think that would be very cool.

slow67

iTrader: (2)

Well supposedly whoever owns Axialflow.com bought everything from Latham in the 80's.