Innodyn turbine?

[keepup]

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

[cjensen]

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.

[Juicegoose]

Thats awsome. I wonder what the fuel burn on that sucker is. Comparable or what?

[cjensen]

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.

[rv6ejguy]

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.

[airguy]

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!

[Kevin Horton]

Originally Posted by cjensen

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.

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.

[airguy]

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.

[Kevin Horton]

Originally Posted by airguy

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.

[airguy]

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.