Genom

I remember as a little kid I was always fascinated with the Blackbird. Reading up on it the first time was an expeirnce. I still remember the single fact that stuck in my head the most for some reason was the plane leaked when it was on the ground. It wasnt until it was in the air going nice and fast that it would heat up and the body would seal properly.

Also, trying to understand the math for the engine spike when I was 9 was not fun :D

Richard Paul

iTrader: (5)

Are you kidding me, nobody can do the math on that spike

Also, the fuel leaks until they get the skins warmed up. They put a minimum amount in on the ground then warm it up and get air to air refueling. The plane grows 11 inches when hot.

The fuel is made with some sort of chemical that normally is used in insectaside. When they first produced it there was a summer when insecteside was in short supply. Then they built facilitys to produce enough. But when it first happened they couldn't say why there was no product because it was classified.

MPG > HP

Around 1995, on my way to work, I heard over the AM that the SR-71 was being retired an making it's last flight out of Burbank. I thot' what the heck I'll go check it out. Drove around kinda lost and saw a U2 take off, then ended up parking along San Fernando road by a bunch of others. Someone shouts "tally one!" and here come da Blackbird. Low and slow headed straight for my position at the end of a runway. Down over some buildings across the street, I could clearly make out the pilot, over my head and down, Down, DOWN!!! till his aft was about 8' off the tarmack. The he lights the burners with flames bout as long as the plane, then cooks off into the LA smog. Heard later that they set some sort of of West to East record, but never got the number. I've got that whole scene available for instant replay, including stop actions, in my minds eye, FOREVER!!! That's the top of my list, ahead of seeing the shuttle launch (once) and land (twice) and viewing a minuteman launch out of Vandenburg while on a commuter flight down from S.F. Oh, forgot the flight of P-51, Thunderbolt, P-38 and Corsair (musta been out of Chino Planes of Fame) comin in from right to left and buzzing the 405 N about 500 (edit, it was more like 200-250) feet off the deck, passing just in front of me ... but they ain't no indigo blue plane!!

d@id

guys guys .. aren't we suppose to talk bout the supercharger here ...

Gomez

Man, it's Richard's thread.....we'll talk about whatever he wants us to talk about!

This is just a more entertaining way of bumping the thread while we await the latest S/C developments......

Oh, and welcome to the show !

Regards, Gomez.

XeRo

we are talking about superchargers here....turbines aren't just for cars man...

rotarygod

Richard it was nice talking to you on the phone today.

I have a question about the gearing system on the supercharger. I need to see if I got this correct. If so it is pretty damn cool and now I like the supercharger more than ever.

I don't know how accurate my numbers are here so let's just use them as an example. You said the boost curve on yours is not like a centrifugal supercharger. This is only good news to me. I know that a centrifugal is geared so that it spins faster at a set ratio to the engine. Let's just say it is 3:1. It spins 3 times faster than the pulley. If I understand yours correctly you have reversed this ratio so that yours accelerates at 1/3 the pulley speed. This would mean that the your supercharger wouldn't spin in near as large of a speed range but actually be tailored to a smaller range. Is this correct or am I just confused? This would explain the fairly flat boost curve that yours will provide across the rpm range. Since it isn't a positive displacement supercharger I can't see any other way of getting boost down low than to design it to spin fairly quickly down low but not accelerate it's rate of spin at near the ratio of the engine. Combine this with a more efficient compressor and this would walk all over a centriugal supercharger at the same max boost level. This will also take far less power to spin than any positive displacement supercharger and is still more efficient. If I have interpreted this correctly, this is going to be one bad *** ****!

Am I confused or do I have it right?

zoom44

oh thats nice if correct. i hope you arent giving away one of his secrets!

rotarygod

I'm not entriely sure if I am correct or not. Near the beginning of the thread he did mention the gearing ratio but I'm not sure if I read it correctly or not.

He doesn't have any secrets! His name isn't "***** ***"!

zoom44

now check our pm's i gotta sign off and get some sleep!
long drive tomorrow

Richard Paul

iTrader: (5)

RG,
Your right about the curve, it goes sort of up a ramp. But it still has to get to where it can "fly". Meaning that it has to do some work on the air to get it speed up then defuse. So while it is better then the cent'l it isn't flat. Now most people are tought that it does not work at low speeds. While this is true in gas turbine practice and as Turbine pwr has said; they still have to start. That means that some work has to be going on. So in our application I take advantage of some "off design" design. And build in as much performance as possable at the off design point.

Now as far as what you said about gearing, I don't think I understand what you are talking about. It would be real nice to have a variable speed drive but alas that isn't going to happen. ZF several years ago made a small CVT (conatant velosity transmision). That could probably be made into a variable speed transmision with todays electronic controls and be a wonderfull thing. I just think it will cost a lot more then the blower.

At the moment my unit uses a 4 to 1 internal planetary gearset. Then depending on the engine peack rpm and it's air flow the pulley ratio is set to a small overdrive. Obviously with a 8500 rpm engine the od has to be less then on a 6000 engine.

I do see what you are saying as far as having a smaller overdrive that would make the curve smaller. But it doesn't make any difference as the portion of the field of operation will be the same,


Anyway it is hard to put in words. I'll show you some graphs. That'll help.
It is not all that bad as people think. There are some aero engineers who opin that it will just stall and surge. It doesn't do that. So why can't it perform at partial speed. yes at idle it will not make pressure like a pd unit. But it does do some work and at a point somewhere about 30% of the rev range the output (flywheel) will start to match and then pass the pd blowers. that is given a same peek boost pressure. I will show you a test like that when I see you.

rotarygod

Our plane lands at 1:33. I'll call you after we get to the hotel.

Ajax

wait, did i hear right, richard will be at 7stock? if so, i look forward to meeting you.

Richard Paul

iTrader: (5)

Sorry, not going at least not on sunday because I'm meeting with Hymee Sunday.
Saturday I'm not sure. My freinds are in from England doing a Donovan tour, Sat might be their only gig in LA. I'm meeting them tonight, just waiting to hear from RG. I guess we shall think about it after I catch up with rotarygod. Man that's a lot of rotorheads in one weekend. Don't know if I could take much more. They are liable to convince me to switch over to the dark side.

rxeightr

Little did you know what you were getting into with us

Tell Hymee I said 'Hey', and all you boys have fun this weekend.

p.s. It is actually called the right side

John Corbitt

The Gulfstream GV has CVT on their AC engine driven generators. They maintain 400hz +- .5 hz. That drove is obviously too expensive and large. I would think there is a smaller one that is not certified that would work It would then be able to maintain a constant pressure over a wide rpm range. I will ask our tech rep if there is a smaller one. Ours maintains 400hz from 58% to 100%


John

Ajax

richard, join us and we will rule the rotary as tuner and tunee!

Richard Paul

iTrader: (5)

John
That's always been a great thought but cost and size has kept it mute.
Hey John, you don't by chance hang out at Ocala airport??
If you do are you familure with Bobby Straman??
He probably has some WWl SE 5A biplanes. They were originaly built here by Tommy Davis of Aviaid fame. They were built entirly from scratch from original plans.
Bobby took them unfinished to Ocala about 20 years ago. When I was down in Palm Beach I never got up to try and see him.

Just wondered when I saw where you lived and had aircraft interest.


Hey Turbine, are you out there? I was wondering if you knew why on some small jets that have the engines on the rear of the hull the cowling is shaped with negative lift??
What would they be trying to overcome?

Gotta go now, Monza F1 qualifying. Fast, fast and Ferrari may not be up front. Oh my God in Italy if Ferrari doesn't win they don't even put the race on the front page. Well, once they did, it just headlined "Ferrari finishes second".

I just don't care I like speed. Cars, planes, boats or women if their fast I love 'em.

John Corbitt

I am based at the Ocala airport, I don't know Bobby Straman by name, but I will look him up once this huricane crap goes through. I also am from Palm Beach. My friends with hangers down there lost them in the last huricane, so we are getting all of our birds out of here. I will let you know on Bobby's status once I get back.

p.s. I just came back from Italy. I only saw 2 ferraries on the streets. Ironicly I aslo saw a 99 Corvette in Perugia and the only car that was in Venice was a Mazda 3 on display. I belive mazda was sponsoring a reggata. I would love to see a rotary in F1 but they say it has an "unfair competative advantage"

John

rotarygod

Richard, sorry I didn't get a chance to get together with you. I really needed more time out there. Just got busy. Turbine was at sevenstock. Met him. He's a cool guy.

Richard Paul

iTrader: (5)

RG, it is a pity I was looking foward to it. Hymee made though. We got a few hours together. As with most Ausie's he was a very personable guy. Somewher down the road I'm going to meet up with Turbine even if I have to go to Az.

Looks like everone got a lot from sevenstock. Good learning curve. I know they can't tell you everything but I would trust RB with what they did expose. As a FI producer I'm concerned with what you said on the other thread. Why do these seals even touch at all if the clearances are so wide??

You can tell that I do not have a good picture of the seal thing having never built one.
But don't try and clear it up with words I need the engine in front of me. Anyway I'll be following this carfully.

Hymee

iTrader: (1)

Yeah - Hymee was indeed very fortunate in metting up with Richard Paul at one of his manufacturing facilities. Very impressive. Somehow after a 12 hour flight and all the rest of it I managed to come across OK. Thanks for lunch - if I knew you was gunna pay I would have ordered up big :p

I should write up a more detailed story for y'all just as soon as I get on top of some of my work I am on while I'm here in the US.

Cheers,
Hymee.

Ajax

richard, remember how we talked about parts expanding? It turns out the seals actually expand under heat. Wonder how we missed that.

Richard Paul

iTrader: (5)

Hymee, since you brought it up I want to tell everyone that I only bought because you're the one who did all the traveling and NOT because you won that little tit we had about the gauge. People should know that we never got around to that topic.


Ajax, You can find a factor for expansion in any physics textbook. I use my Machinery's Handbook because it happens to be handy. I only know those for aluminum and steel in my head because that is something I use. You will find any material you want in these books. But you must know the material and the exact heat rise. You must know the size of the part. Remember it expands in all directions.

As a practical use for this information sometimes I make pulleys that have a large blower drive part and a smaller accesory drive part. In order to save having to machine a bunch of matirial off the small groove portion I make a blank of each set of grooves and bore a hole in the bigger portion. this hole is smaller then the part we are going to put into it. Knowing how much the part will expand we heat the out ring and freeze the inner part.

When the temp are stable you just drop the bigger part into the smaller hole. Which temporarly is bigger. When the temps become the same there is no way you can take them appart. Done right that is.

Anyway I do not have those books here. If I remember I will look up the possable materials tomorrow. I think someone said the seals were cast iron. I must say that CI has a low expansion rate. Even though I don't know exactly I think it is around .0006 per inch per 100 degrees F. I'll look it up tomorrow.

Ajax

There's 1 error in all of this logic: not all physics text books have these tables, lol. That was actually the first thing I did and that's when I remembered, I took physics for electrical engineers and we barely covered material science.. U know what you find in our books? lots of electromagnetic theory, magnetism laws, gauss law, faraday's law, ohm's rule (apparently it's not a law.. whatever, physics books are dumb :b)

But yes, a normal physics text book would display it (assuming i knew what the seals were actually made of). I guess i could look around and find out real fast. Maybe I'll do that.