Lets see if I can answer some of your questions. An Axial Flow compressor is the front section of your normal jet engine. The principal of it's operation is the same as a wing that lifts an airplane, causing a high pressure area under the blade. Then the air is stalled by a static blade that takes the energy out of the swirl and turns it into pressure. The operation is repeated in the next stage. This compounds the pressure rise since the next stage doesn't know it is starting with boosted pressure already.

Adiabatic efficiencies in the 93% range are normal for gas turbine engine compressors. This compares to 50% for roots, 65% for centrifugal. I don't claim to reach the numbers that jet engines do but we regularly get 85% from my blowers.

This translates to lower outlet temps and less drive power lost. We don't use intercoolers on our regular 7 psi street systems. The added cost and complication is just not worth the trade off. The added heat of this blower is not enough to need reduction.

The amount of air entering the engine is not necessary described by boost. It is necessarily to know the mass. There are mathematical means of deriving this but unless you really want all of those equations, I will not lay them on you.

I shouldn't say that because someone is going to scream they have to have them. But this way I don't have to type them out right now. If there is a way to get attachments in here that would be a better solution. I could just use some of my prior writings and people who don't want to bother with them don't have to open them. Someone please let me know on that one.

I have taken nzaizar up on his offer to produce some of my photos on here. I have sent a few and I'm sure he'll post them shortly. Basically I can tell you that this unit is smaller and lighter than other units on the market. It is about 5 inches in diameter and 10 inches long. This includes an internal planetary drive that brings the belt overdrive into line. It weighs about 11.5 Lbs.

By the way some of you might be familiar with my prior work. This was the axial flow supercharger for domestic V8's. Marketed under the name "Latham Axial Flow Supercharger". This was built from 1956 to 1965 in Florida. I bought the company in 1982 and redesigned it for modern engines and manufacturing. They were sold from 1983 to 1992.

Each time it was discontinued from production was due to manufacturing costs being out of reason. Now we have a new method that cuts them completely out of billet bar stock. When you get the pictures you will realize the complexity of this operation.

I am going to stop this post now and wait until you get the pictures. Really I'm stopping because I only type with one finger and get tired. I'm sure with all the fertile minds on this forum I will be getting lots of questions anyway.

 

Pics posted for Richard

 

This sounds very interesting. I'm in the market for a supercharger but right now I'm on the fence between waiting for the BRP Roots blower supercharger for the S2000 and the existing centrifugal blowers by Comptech/Vortech. This also sounds very interesting ... The one question I have is if you develop it, how long would it take to develop it for both the 2.0L engines and the 2.2L engines? Any approximate pricing information?

Also, what kind of power and when would you expect it? For example, a roots style blower makes power almost immediately but the gains are not as high as on a centrifugal. But with centrifugal you need to wait until you're in your powerband to really make power.

Just trying to get a feel for the advantages/disadvantages of this type of blower.

I couldn't get the link to work on rx8club.com so I'm sorry if many of these questions have already been answered there.

Thanks and I hope you decide to create a blower for our cars.

 

That's a nice piece of engineering. Small enough that you could fir it inline with a turbo system.

 

Subscribing.

 

This truly is another alternative to keep an eye on.
I just wish that http://www.rx8club.com/showthread.php?t=29778 was more cooperative.

 

What kind of pressure ratio do you get across each stage? And why multistage at all? For the kind of pressure ratio you are talking about, I really don't see any reason not to use a single stage compressor.

Frankly, I'm dubious about the device you have pictured here. There are a number of things that look wrong to me.

Edit: I guess it would be helpful if I listed some of them:

1) All stages seem to be identical, which implies they are actually producing only a very tiny pressure rise per stage. I guess that also fits with the idea of taking five stages to produce only a 1.5 PR. If the overall pressure ratio is 1.5 and there are five stages, then each stage has a pressure ratio of about 1.09.

2) Each stage of blades has tip clearance losses and friction and form drag losses. So do each stage of the stators. This is why you try to minimize the number of stages. (As well as to save weight and cost and size.)

3) It just doesn't look like there will be enough massflow, but I could be deceived by the scale of the pictures.

4) I don't see how that could possibly be cost-competitive with a single-stage centrifugal compressor.

5) Axial flow compressor efficiencies are very vulnerable to off-design operating points. This is why jet engines use variable geometry stators. I would think this design would be very vulnerable to robbing you of power in the "normal driving" engine speed range, even if it does increase power near its design point.

Just a few thoughts. Actual installed test data would answer all of them, of course. Do you have any of that? Since there are currently at least two proven supercharger kits for the S2000, you would have to have some sort of really big advantage to take any of the market. I can't see how you are likely to have any advantage at all, except maybe in marketing to people who think it looks cool.

 

Yes the rx8 server has been bad for two days now.

Mike, The compression is about 1.12 per stage. Now if you are familure with gas turbine technology you are used to more comp. We cannot utilize that design because we operate in a much wider rev band then they do. We have no choice, it must work with the host engine. The unit operates mostly in off design mode.
Also it must be machinable, these are made from solid bar stock. There has to be room for a tool.

Having said all that if you see so much wrong with my design maybe you should come to work for me. Just need to tell you I'm the only one working on these type parameters for an axial flow compressor. And I've been doing it for 20 years.

I don't want to come off defensive but there have been many very smart people look at my work. Not the least of them three Professors from major universitys.
I even showed it to Boeing engineers for suggestions.

As you can calculate we need four stages for this application. We also produce five stage for those inclined. These are nessasary to get a broad pressure curve. As you can imagine this is the only place such a compressor sees itself dumping into a positive displacment reciever. Then have it's inlet density changed by the throttle setting.

I know there will be more so someone tell me how to insert documents that I have already written


Ok so I"ll edit my answers. Your wrong about the stages being the same, look close. They are different in geomitry as well as size. As for tip clearances look closer, the stator is 0 clearance. Pat. Pend. I already gave you the pressure rise . Is that it. Yes there are dyno charts but no one will tell me how to post them.

 

FYI, I am a Boeing engineer. Before that I worked in the turbine aerodynamics group at GE Aircraft Engines. Like I said, actual test data would satisfy my concerns. There is enough different between this application and a real gas turbine engine that I might be misled by appearances.

 

My son is an engineer with Boeing also. The group I spoke with are at the Chatsworth facility. They are working on a design program, the name of which I forgot.
Did you notice I responded to your edit?
BTW there is not one blade design that repeats here not even rotor to stator.

I built units for large domestic cars that had repeating geometry. That was because they were investment cast and I couldn't afford that many molds.
In that case it took a lot more stages.

Oh yeh, the flow on the conpressor you see here flows 650 cfm. And makes 12 psi.
I can make whatever flow I want by changing the size of the blade. Within the confines of the envolope. I can make all the pressure i want by adding stages. I built a 6 inch dia blower with 7 stages that flowed 1800 CFM at 19 psi.