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Innodyn turbine?

keepup

Active Member
In looking through the history of this particular section, I was surprised not to see a rant on these guys (http://www.innodyn.com). Well, I first took a look at them a couple of years ago and they haven't made much progress since then. It's also not a good sign when their latest updates were from 8 months ago. If they ever get these turbines in production it could be a compelling alternative with as reliable as turbines are. 255 HP, 188 lbs, $35k, multiple fuel compatibilities, and minimal maintenance, hmmmmm??? I'm wondering the effect on an aft center of gravity and whether the wings would have to be moved rearward? Their videos are pretty cool. Any opinions out there?

John
 
Hi John,

If you do a search on 'Innodyn' on the forum, it has been discussed at great length. Check the 'Alternative Engine' forum. LOTS of info on the board about Innodyn.

Regarding CG, the engine is placed WAY out front on an extended mount. Wings do not need to be moved with the weight so far out there.

There is a guy in your state that has/had one on his RV-8...first customer flown version...then it overheated and that was the last we all heard of it.:rolleyes:
 
They say 7gph/per 100hp. So, at 165hp, it burns 11.5gph, 185hp, it burns 13gph and so on...and that's ALL the time, from startup to shutdown.:rolleyes:
 
Not dead yet. A little bird told me new financing is on the way. I wish them well. It is the ultimate experimental development in engines.:)
 
That sure would be sweet - I'd put up with the fuel burn just for the cool factor of hearing the turbine spool up on the ramp and watching everyone's head swivel your direction!
 
They say 7gph/per 100hp. So, at 165hp, it burns 11.5gph, 185hp, it burns 13gph and so on...and that's ALL the time, from startup to shutdown.:rolleyes:
7 gph/per 100 hp implies a specific fuel consumption of about 0.47 lb/hr/hp, which is simply not credible for a small engine from a tiny company. I might believe 0.6 lb/hr/hp - i.e. fuel consumption about 30% higher than they claim.
 
That's their advertised fuel burn numbers, completely unsupported by outside 3rd party testing as of yet. Some comments have been publicly made (by people with unknown knowledge of the engine) that the fuel burn numbers are a bit optimistic. The company has said before that they will conduct open-to-the-public fuel burn testing with an independent lab at some point in the future after they finish tweaking the fuel controller, but it hasn't happened yet.
 
Some comments have been publicly made (by people with unknown knowledge of the engine) that the fuel burn numbers are a bit optimistic.
They are working with the same laws of physics as everyone else, and much smaller budgets. That suggests that they will likely do a bit worse than the long established manufacturers.

Have a look at the SFC info on military turbo-prop and civil turbo-prop engines. Note that the typical SFC gets worse as the engine gets smaller. As the engine gets smaller, the area to volume ratio goes up, and this makes it harder to achieve good efficiency.

I'll bet you a case of beer that a credible, independent test will not substantiate their claim of 7 US Gallon fuel burn per 100 hp within the next ten years (I wanted to say never, but then I could never claim on the bet).

It is wonderful to be hopeful, but anyone who wants to send them some money should have realistic expectations.
 
Actually, that SFC can be achieved quite easily - but not cheaply. The hotter you run the burner can and the first turbine stage, the more efficient the engine is. It's not an inherent physics limitation - it's a temperature and material limitation. Give me a machinable metal that's good for the tensile strength required at temperatures 200C higher than the current designs, and I'll take that bet.
 
What dissapoints me with the innodyn is the lack of a propeller control system (be it an electric pitch control integrated with the FADEC or a more conventional hydraulaic governor)... Surely this is a neccesary part of any turboprop engine...?

The only flying examples have used manual control (ie change power to the engine, then adjust pitch to suit) which has ended up with high pilot workload..

Cheers,
Matt
 
It's not an inherent physics limitation - it's a temperature and material limitation. Give me a machinable metal that's good for the tensile strength required at temperatures 200C higher than the current designs, and I'll take that bet.
I guess I consider material limitations as being due to the laws of physics. Do we agree that their claimed SFC appears to be wildly optimistic?
 
From the horse's mouth

7 gph/per 100 hp implies a specific fuel consumption of about 0.47 lb/hr/hp, which is simply not credible for a small engine from a tiny company. I might believe 0.6 lb/hr/hp - i.e. fuel consumption about 30% higher than they claim.

Here's an example of my real-world turbine fuel consumption. Using 1250 lbs. ft. of an available 1600, while spraying cotton, this figures to about 400 SHP of an available 680 SHP (max takeoff). My REAL fuel burn is a consistent 47 GPH of Jet-A. The math then figures 11.75 gal/100. I've been using this airplane and these numbers for around 8 years now. Kevin's correct concerning scaled down turbines becoming less efficient.

Also bear in mind that I'm at 328' ASL and work a few feet off the crop, so at my near-sea level altitude, the fuel burn is as great as it gets.

Regards,
 
I guess I consider material limitations as being due to the laws of physics. Do we agree that their claimed SFC appears to be wildly optimistic?

Yes, we agree - I would say it's probably 20%-30% optimistic.

Pierre's numbers I think are more realistic (at least for low-altitude work), and as pointed out these will only get worse as you scale down the engine. There would have to be either a significant advance in technology, or a significant amount of voodoo, inside the Innodyne turbine to get the fuel burns they are advertising. I won't entirely discount the technology, it has happened before, but I find it unlikely and will remain skeptical for now.
 
.47?!

0.47 spec is on the order of larger plant-based diesels, arguably some of the most efficient combustion devices on the planet. Not sure if they will be able to back that number up - if they do, they will be very rich . . . . and I'll fly one. Rick 90432
 
0.47 spec is on the order of larger plant-based diesels, arguably some of the most efficient combustion devices on the planet. Not sure if they will be able to back that number up - if they do, they will be very rich . . . . and I'll fly one. Rick 90432

.47 is about what an auto gasoline engine does for SFC these days at best power AFRs, stationary diesels are in the .27 range. I think a simple, uncooled, single spool small gas turbine like this will be hard pressed to get better than .6.
 
No reply, an news

I emailed them thru their message server, on their site and got zip response after two weeks? I am devastated. :rolleyes: There is nothing new on their site since April 2007?

What happened to the RV-8T? The innodyn RV-8 guy posted here a while back. Last word was the pilot who was going to do the initial flights was sick? Innodyn has it on their site, last posted Oct 2006.

Any news? Any one? Is it done, put a fork in it?
 
What happened to the RV-8T? The innodyn RV-8 guy posted here a while back. Last word was the pilot who was going to do the initial flights was sick? Innodyn has it on their site, last posted Oct 2006.

Any news? Any one? Is it done, put a fork in it?

this is the last post from him earlier this year.. :(

Last edited by Jim Benson : 01-04-2008 at 01:52 AM.
Jim Benson
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Join Date: Oct 2006
Location: Avon, CO
Posts: 2


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hello From the RV-8 Turbine guy
I was doing a google search on my name and found this thread. I had no idea there has been so much talk going on about my plane, RV-8T N333JB, albeit a year ago.

Here is the latest: The plane last flew in Dec. 06, it has a total of 8 flights. The test pilot and I were doing a ground test on the FADEC system and overheated the engine slightly. Innodyn said to send the engine back so they could look at it. So I FedEx'd back and have not seen the engine since. The inventor said he has rebuilt it and all is good but refuses to send it back. I would even pay for shipping. There is turmoil in the company as to who owns what and how things are going to be run.

I am hoping in the near future things can be worked out so I can get my engine back and we can resume flying and testing.

So we have started to build another RV-8. We are putting an IO-360 on it from Aero Sport Performance out of Kamloops, Canada. This one will also hae the Fast Back conversion. Should be flying in the next month or so. Meanwhile, the other plane sits in the hangar collecting dust.

I am going to give Innodyn this year to get everything worked out. If not we will put a piston on the thing and fly it.

I am bad about coming here to look to see what is going on. I have checked off to send me email notification when some one posts to this thread.

jim benson
 
Thanks for the update, Jim. Sorry to hear about your misfortune. I hope Innodyn comes through with the engine soon. Have you flown it enough to get an idea of whether the performance is in agreement with Innodyn's claims?

Thanks,
 
Thanks for the update

I am going to give Innodyn this year to get everything worked out. If not we will put a piston on the thing and fly it.

I am bad about coming here to look to see what is going on. I have checked off to send me email notification when some one posts to this thread.

jim benson
You sir are ONE very patient and understanding man. Even though there is criticism, we are ALL pulling for you Jim. I am just glad you are OK and its just money, it could be worse. Also even though the group has criticised the engine we are all secretly hoping we are wrong. Hope you don't have to sue. I hate to say it, but may be its a good thing he has not sent it back. You would be the only one really flying around. There was that RV-4T but have not heard or seen that in a long time either. Thanks for the update.
 
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