Yep now there are at least 4 economical ways to make well-balanced compressor rotors:
plunge EDM, 5-axis wire EDM, powdered metal, sinter+hot isostatic press. There are also several affordable ways to do high RPM balancing.
I hope he makes this thing.

 

Axial compressors are best for HIGH flow with LOW compression.
Centrifugal compressors are best for LOW flow with HIGH compression.
A piston engine requires [relatively] LOW flow with HIGH compression.
Based on those [somewhat oversimplified] facts, which compressor design would you pick for your car engine's compressor?

This car application of an axial compressor sounds really cool; however, it also appears more of an engineering toy than a worthwhile winning racing technology.

To make an axial compressor work in an automotive application, you would have to de-engineer it to the point where it really isn't competitive against a good centrifugal design. I'm not just talking about price either; even in the turbo era, F1 cars used centrifugal compressors--and if anyone has a 'sky's-the-limit' budget, it's an F1 team. In fact, even aircraft piston engines use centrifugal compressors.

An axial flow compressor is the most efficient way to compress a gas, but you have to think: "Do I really need that much mass flow for a given compression ratio?" For a piston engine, the answer is no; you'll blow up the engine!

All that said, I would still love to see this in production!

Who knows... maybe when CVTs become more popular this axial compressor (semi-worthwhile for a CVT application) will become a reality. Still don't think it'll beat a centrifugal compressor, but I'd love to be proven wrong.

 

[QUOTE=MinimumEntropy,Sep 28 2007, 06:54 PM]even in the turbo era, F1 cars used centrifugal compressors--and if anyone has a 'sky's-the-limit' budget, it's an F1 team.

 

"turbo era" - Turbochargers always use a centrifigual compressor.

I think it has more to do with entry and exit angles than how the boost is produced. With a centrifigual compressor boost increases exponentially with respect to RPM and with an axial flow compressor boost increase is linear with respect to RPM. An exhaust driven turbocharger produces more boost across the rev range and doesn't blow up the engine as long as the boost is never excessive, so I can't see any reason to think that the more conservative profile of an axial compressor could be harder on the engine in any way, as long as the engine isn't overboosted.

The axial flow compressor is more effecient than the cengrifigual compressor, all else being equal, but here either the input or output of the axial flow compressor has to turn 90-degrees, and for all I know that may offset the advantage in effeciency. It would be interesting to hear Richard Paul's thoughts on this, because I'm sure he understands it a heck of a lot better than me, and where I just have vague ideas, he's got hard facts.

 

[QUOTE=MinimumEntropy,Sep 28 2007, 06:54 PM]Axial compressors are best for HIGH flow with LOW compression.
Centrifugal compressors are best for LOW flow with HIGH compression.
A piston engine requires [relatively] LOW flow with HIGH compression.
Based on those [somewhat oversimplified] facts, which compressor design would you pick for your car engine's compressor?

This car application of an axial compressor sounds really cool; however, it also appears more of an engineering toy than a worthwhile winning racing technology.

To make an axial compressor work in an automotive application, you would have to de-engineer it to the point where it really isn't competitive against a good centrifugal design.

 

This is just a pipe dream.

 

Nobody is forcing you to read it.

 

 

Have you ever been involved in any kind of new product development?

I'd really rather deal with a company that takes the time to sort out their products than with a company that sorts out the problems after they've started selling product.

 

Be nice if they were to produce something before we run out of fossil fuels though.