The Renesis theoretically displaces 1.3 liters or air per eccentric shaft revolution.

The piston engine displaces all of it's air in 2 complete revolutions. Using this number, the rotary displaces 2.6 liters of air.

The rotary however needs 3 complete revolutions of the eccentric shaft to displace all 6 chambers and this brings it to 3.9 liters. It does NOT displace 3.9 liters of air per revolution.

All of this assumes 100% volumetric effeciency.

*** MOD EDIT by Omicron***

Post removed for vulgarity and lack of content. Do NOT do it again, SurreyPuma.

that's enough of that mr. surreypuma. if you can't have a conversation without resorting to that kind of lanquage you will be banned. consider this a warning. again i suggest to you that you read the rest of the thread. you will find some of the answers you seek have already been given.

Excuse me, this sort of nonsense is not tolerated here. You have crossed the line.

You come in here calling people names and telling the they know nothing, yet you show your ignorance very early on in your misconstrued idea of the displacement of the Renesis. The Renesis displaces 1.3 L of air every revolution. I have posted graphs from pratical tests showing the actual mass flow rate of the Renesis, and it excedes 100% in at least 2 places on it RPM band. It has high volumetric / mass flow efficiency for a naturally aspirated engine.

Please show some respect to Richard, and the practical work he is doing.

Cheers,
Hymee.

PS - How fast does your text-book get you down the 1/4 mile, or round a circuit race track? I don't mind asking that cause I have the runs on the board on both.

And I know some very nice people who suffer from Cerabal Palsy ("Spastics") through no choice of their own. Your insult is offensive. Please withdraw your insults, and make some valuable contributions to this thread.

here we go agaiN! mods where are you?

dont let ppl like him speak for the rest of us. keep working at it and we await your final product. we leave it to pros like u. :)

Richard, very very interesting thread. I can't wait for more.

Im only pointing out facts and figures from an aircraft engineers point of view.
http://www.geocities.com/henry_yu_84/tc.html
http://www.fact-index.com/w/wr/wright_r_3350_32w.html

That's called turbocompounding. But you probably know that. I thought of it for my RX8 : a bit of a torque boost together with an FE improvement. Unfortunately, it would be at a price!
Why don't you develop your idea in another thread and let this one to axial S/C.

Bump? How about an update, Richard? I'm also curious on how you're thinking about plumbing this unit...

richard,
i'm back in town if you need more pictures hosted.

I bought the 8 for its unique engine. If I go with FI, I would like for it to be unique as well. I like the concept of axial flow. I don't see compresor stall as an issue since it is mechanicaly linked to an engine. The only time it might come into place would be at high engine rpm and low throttle position. A pressure releef valve would take care of that.

As far as turbine engines go, I have seen the increased fuel eficeincy in engines as they have gone from centrifugal to axial. The same should apply here.

Count me in for one.

John

p.s. I have not been able to see any photos on this thread.

Centrifugal flow compressors are shorter than the axial flow compressors and becasue of their spoke like design they can accelerate air faster and immediatley diffuse it into the direction of flow.
Advantages are of centrifugal comps. are :-
1) High px. rise per stage, compression ratios upto 15:1 possible.
2) Good effiency over a wide rotational speed range, this is from idle to full rpm.
3)Simplicity of manafacture, relatively low cost.
4)Low weight
5)Low inertia loads aids spool up.
Disadvantages are:-
1) Large frontal area for a give airflow. 2) More than 2 stages impractical

Axial flow flow compressors require a large amount of stages to gain a high pressure rise, unlike the centrifugal compressor which has very high compression ratio's the axial flow can only manage a pressure rise of about 1.25 per stage. To gain a large compression u will havbe to add more stages, hence why most turbines have up to 13 stages of compression.
Some advantages are:-
1) High peak efficiencies from RAM AIR, created by its straight through design (N/A to RX8)
2) High peak pressures attainable by addition of extra stages.
3) Small frontal area
Disadvantages
1) Difficulty in manafacture and costs.
2) Relative high weight
3)Low pressure rise per stage 1.25:1
4) High inertia.
5) Poor effiencies at low speeds

One question and one comment :

Q : Can you explain to me the main reasons the aero-engine industry moved from centrifugal to axial type compressors?

C : Considering the above disadvantages of axial compressors, Richard will gain the status of genius if or when he'll come up with a good automotive application for his axial compressor. He seems to know what he's talking about and I really hope he'll succeed.

PS : 1.25:1 pressure rise per stage. Give me 2 stages and I'll be happy!.

I certainly don't think the lower pressure rise per stage is an issue here...Richard has already stated his initial design was making too much boost.

jds

I have listed the advantages and disadvantages above, im sure u can work out why aerospace moved. Though some engines use both and some use just one type. Garrett TPE331 is two stage centrifugal, the TFE731 use's four stages of axial flow and then a centrifugal compressor to really increase the pressure. Even at low RPM the axial will have to be turning at quite high speed, this will obviously sap more power from the engine, more so than from a centrifugal type compressor.
Next point where the hell are u going to fit an axial flow compressor in the engine? Why do u think people use centrifugal compressors? Yes, they both do the same job but clearly the advantages of centrifugal are clear. If Richard can come up with a good idea ill take off my hat, but im sure it would have been looked at before, yes it would work im sure but not with sacrifice, theres no such thing as a free lunch, is there?

SurreyPuma, not trying to be a jerk or anything, but have you really been reading this thread? It HAS been tried before...by Richard...with success! Now, I don't believe its been on a rotary before, but we'll see soon enough (hopefully).

As for your size concerns, Richard showed some pictures of the unit he's working on and it didn't really look that big to me. Hey, maybe this will be a reason for one of those funky off-center hood bulges :-)

jds

Fair enough, maybe it will work but i can assure u somewhere down the line there wont be advantages, as i said there is no such thing as a free lunch, maybe it works but does it work on the track? Does it work efficiently? Lots of aircraft engines have been developed and how many are succesful? Why isnt this design used everywhere by people?

I'm just guessing here, but I believe you said yourself it was more complex and expensive to make. That could be a factor. I think Richard is using some proprietary designs as well, so maybe they've found a way to get around some of the inherent issues, because obviously you're right...there are pros and cons of every design choice. Maybe it will be the best thing since sliced bread but cost $20K for the kit :(

Richard, as a gesture of good will I'd be happy to accept a free sample :D

jds

I'm having some trouble posting here. I keep writing posts and then the thread doecn't remember me. So I'll be short. First does anyone know what happened to the pictures and downloads???

If someone out there wants to build a centrifugal blower please do. I'll support your effert and all your rights to do so. You just go right ahead and put up a few hundred thousand dollars a few years of your life and I'll cheer you on.
Now that is enough on that deal, I will not touch it again.

Let's test the thread, if it works I'll write another
RAP

really sorry to hear you've been losing posts Richard!! if it doesn't go through when you click "ok", try just backing up in your browswer and hopefully it'll remember all that you've typed. if not, before you post try "Ctrl-C" copying the whole thing, just in case.

i for one would hate to see frustration of wasted time keep you from posting more.

I believe the same question can be asked of the rotary engine.

Richard, sorry to hear you are losing posts... not that you need any advice, but perhaps you could type up your responses in a text file and copy/paste it over to the browser to be safe. I just don't want to miss any of your posts on account of flaky browser behavior. :)

Surrey, no one claimed this was a free lunch kind of thing. I, and at least a few others, see this as an interesting development for the RX. Richard has the experience of building these for automotive applications, You have related experience but how relevent is it going to prove to be. Richard isn't asking anyone to take his word that it will work. He's prototyping it right now to prove if it works and spending a good deal of his ( or at least his companys' ) money to do so.

I don't doubt you know a great deal about aircraft turbines and much of what you've posted I find interesting, I just think that it doesn't directly apply to most of what Richard is doing. I may be wrong but each stage should compound, so the compression isn't

1.25 X 4

but rather

1.25(1.25(1.25(1.25))).

( I hope my notation is correct algebra is way in the past for me ) Which would produce quite an adequate amount of boost. So I don't see a problem with the blower making enough boost. The picture of the 5 stage test unit is barely larger than a tissue box which is smaller than the smallest centrifugal blower for automotive use that I know of. You may be right but there are literally 1000 example that prove otherwise.

The bottom line is if Richard suceeds people will likely buy, If he fails then it's no loss for me someone else will find a way for FI on the Renesis.

*** MOD EDIT ***

Message deleted to prevent another flame war.

I enjoy Richard's approach to sizing the supercharger into something that is smaller than a WD-40 can. I mean, we all don't want to slap a big T66 turbocharger on to make big power gains. I wish I knew more about axial-flow supercharging, but there's not enough information out there that I can find. Any help? I wish you the best Richard :).

I'm not typing anymore until this thing gets fixed. It's probably at my end.
Lets see if a quick reply goes through.