200 pound, 200 horsepower turbine?

[ekisbey]

I don't know if any of you have seen this or not... but I haven't seen it mentioned so I figured I'd toss it out. While the wife and I were looking into engines we came across this.

 

http://www.atpcoinc.com/Pages/Requests.html

 

Sounds like it's still in development. Nevertheless, the drool factor is off the chart.

[John Slade]

This looks a lot like the turbine I saw on Wayne Lanza'a booth at Sun & Fun last year, and the year before. I hope they come through with a reasonably priced product, and a two for the price of one intro deal. One of these on each wing of a Cozy would be interesting.

[ekisbey]

Just how fast are you planning on going?? That's as wild as the guy with the 13B and ducted fan installation on his Long EZ... Just out of curiosity, where would you fit two?

[John Slade]

>Just how fast are you planning on going??

With two of those things you could probably top 300kts. Of course, balance and flutter would be a big issue at those speeds but it would be "interesting". Actually I was thinking more about redundacy than increased speed.

 

>That's as wild as the guy with the 13B and ducted fan

Perry Mick's experiment is more about the ducted fan than it is about speed. I dont think he's got over 160kts yet. Unfortunately increased speed is what he needs to make the fan effective.

 

>Just out of curiosity, where would you fit two?

That's easy. In pods mounted on each end of the spar, just inboard of the aileron. One builder already built the structure for this - I think it was Charlie Airesman.

[Joe Cygan]

Group,

You would not want to put two of those engines on a Cozy.You would be burning around a total of 25 to 30 gallons of fuel an hour.Now you are defeating the whole purpose.You would not need two engines for redundancy because if done correctly one turbine is always more reliable than one horizontally apposed certified engine.The web site did not give any pricing information,at least that I saw.The price is probably in the low to high thirties for the engine alone.I could be wrong.

 

Joe Cygan

Cozy MKIV #1022

[ekisbey]

Actually, when looking at the numbers on the video and the table listed elsewhere on the site, a rate of fuel burn in excess of 10 GPH only seemed to occur at the high end RPM range of the engine. Now granted, even at a slow cruise you'd still burn between 10 and 20 with two engines... but imagine the thrust you'd have available to play with.

 

It's fun to imagine, but I wouldn't consider it seriously. At least, not on a cozy. Too complex, too heavy, too expensive.

 

Just how fast could a Cozy go, at least theoretically? How fast is the airframe rated to?

[Rui]

Anyone have any real idea how much such an engine would cost? Why do you say in the 30's?? If this is the case then I think they should change their name or risk false advertising charges. It is definitely not "affordable", at least not to me (and especially when you convert that to the monopoly money we use up here in the Great White North).

 

I do like the fact that it can burn Jet A. In my research into aircraft engines one thing is abundantly clear, 100LL is going the way of the dodo. It seems that the only reasonable alternatives are the newer diesels (which are also not "affordable") or the Mazda/Subaru auto conversions. If they made this available for 15-20K I think they would sell like hotcakes...

[Joe Cygan]

Gee Ekisbey,You got me all excited with those fuel burn numbers.I called the company myself and talked to Chuck the owner.At best,you might see four to seven gallons burned per hour during idle/taxi.The hard numbers per Chuck are about eleven to thirteen gallons per hour at cruise per single engine.The turbine engine itself is constructed from apu or gpu parts which is pretty typical for these little turbine engines.They designed there own fuel control for it. I myself have converted a Sunstrand APU engine on a past project and found a Fuel burn of 14.5.with a reduction of my own design.

 

Rui, Their statement is true,"affordable jet engine".Most USED certified turbine power plants are well over one hundred thousand dollars.So,the twenty-seven thousand dollar price tag for a put together turbine engine is very good,and remember at least another ten grand for a good prop.

[ekisbey]

Hmm, Okay. I was wrong with my guesstimates on fuel burn.

I should have mentioned that it was a hip-shot guess for two engines based on the numbers I saw in the video, thinking offhand that two engines = 1/2 the throttle setting on each to achieve the same power/thrust. Yeah, I know, I wasn't thinking it through.

 

I'm no expert on turbines, but it seemed to me that the fuel burn spiked quickly toward the upper RPMs, about the time it passed through 160 horsepower. 14 GPH doesn't seem *too* extravagant to me, considering it hit 11 gph at 160 horses and the damn thing will run on just about any fuel you put in it. Yes, you might at first expect a decreased range with the higher burn rate but you can't really determine that until you figure out how fast "cruise" with this engine really is, right?

 

I'm curious about how the thrust it generates compares with a conventional ICE of similar "horsepower." How would you determine the relevant fuel consumption of each engine needed to generate enough power to maintain 180 mph at a given altitude?

 

I'm gonna keep a close eye on these.

[Joe Cygan]

.....Remember,when you compare fuel burn to turbine VS reciprocating engines they all have different cycles to operate and believe me,I'm not an expert either.To understand the high fuel consumption on turbines you have to think of the "Brayton cycle".It basically describes the events that take place in a turbine engine as the fuel releases it's energy.The same events happen in four stroke reciprocating engines,intake,compression,combustion,and exhaust.The big difference here is that the turbine cycle happens continuously,thus more fuel.

 

Agreed,four-teen gallon per hour is not*too* extravagant FOR A SINGLE ENGINE!The reality with these small turbines is that they sip fuel all the time,taxi or cruise.You will find out that GPH rate will always remain high through the functioning operating ranges.So,you always think about it that way and you will always be fine when flight planning.If you are trying to figure out what a particular fuel burn for a certain altitude at a given airspeed is we'll,good luck.You have to factor in a lot of information.First of all you need an airplane for the study and a engine(that's the hard part).Than you have take in consideration pressure energy and ambient air,weight,wind ect.So,when you find out,let me know.Which brings me back to the fact that any small twin turbines will burn at least 24 to 28 gph and that's a lot of fuel/weight to carry on a small homebuilt.Keep it simple ,use one engine.

[Jim Sower]

I couldn't access the site, but I believe I've seen a similar one recently. IIRC the one I saw produced around 300 hp. Certainly in the case of jets and somewhat more modestly in the case of turboprops is altitude sensitivity. Turboprop would be a lot better at altitude (are we back to pressure again? ) The $27k is about the same as an O-540. Similar fuel burn, lighter weight, order of magnitude better reliability. Climb hard to 20k, cruise at 180 kias (about 270-300 true?). Perhaps you'd have to plumb a couple of external tanks. But 14 gph isn't all that bad if you're making upwards of 250 kts. MPG would be about the same as a rotary.

The bucks for engine and prop, at over $35k would kill me ... Jim S.

[ekisbey]

Well, who knows... Maybe the price will go down? <hopeful grin>

[Wayne Hicks]

Okay guys....

Put FOUR turbines on the dang thing! Besides the speed bucket built into the wings, the other more substantial limiting factor will be flutter. I don't personally know where the flutter speed boundaries are for our airfoils, ailerons, and elevators, but I'd be willing to bet they're not high enough to support flirting with the speeds to which these turbines might push our planes. There would be some substantial rework required for the foils.

 

Wayne Hicks

[Wayne Hicks]

Okay guys....

Put FOUR turbines on the dang thing! Besides the speed bucket built into the wings, the other more substantial limiting factor will be flutter. I don't personally know where the flutter speed boundaries are for our airfoils, ailerons, and elevators, but I'd be willing to bet they're not high enough to support flirting with the speeds to which these turbines might push our planes. There would be some substantial rework required for the foils.

 

Wayne Hicks

[ekisbey]

Speaking of turbines on canards, Beechcraft has a twin turboprop canard called the Starship. Anyone seen it?

[marbleturtle]

Speaking of flutter limits... Is there a Vne for the Cozy design? I haven't found one yet.

 

If you want to do 2 turbines, how about the design of those Venuzualianitian (?) guys with the twin engine compound counter-rotating prop?!?! That should be easy to duplicate with turbines!