What GA needs

"Andrew Sarangan" wrote in message
oups.com...
On Sep 10, 6:28 pm, "Capt. Geoffrey Thorpe" The Sea Hawk at wow way
d0t com wrote:
...
"Small Turbine" and "Gas mileage" - you only get one - the thermodynamics
just don't support both without real exotic materials.

Other than that, though...

--

I have heard that argument many times, but I have never seen that
thermodynamic argument presented. I just borrowed the book on Aircraft
Gas Turbine Engines from the library and plan to read it to find out
what the real story is. My suspicion is that the limitation is in the
materials, not thermodynamics. It may take a significant investment,

That's why I said "without real exotic materials"

The materials limit the maximum termperatures. The maximum temperatures
limit the maximum efficiency. Also "small" (and I assume "reasonable cost")
rule out regenerators to capture some of the waste heat (common on
stationary applications)

but if the military is also interested in similar things it won't be
that hard to find the R&D suppport. I've heard that small turbines are
of interest to the Air Force for potential use in UAVs. A UAV and a
small GA airplane are not that far apart. In fact, the predator is

True, but the military tends to care less about fuel cost and more about
being able to use the same fuel in everything so if you have fuel, you have
fuel.

There were a number of programs in the 60's for turbines and direct
injection piston engines that would run on "any fuel' that was available...

...
Having said that, I know of at least two companies working on small
turbines. One is Innodyn, and the other one is M-dot. The latter one I
believe has some DoD contracts to be build turbines for UAVs. I doubt
these companies would even exist if the basic physics is flawed.


Nothing wrong with the physics. Small turbines work. And for some
applications they have big adavantages. Fuel quantity per horsepower-hour,
however, isn't one of them.

--
Geoff
The Sea Hawk at Wow Way d0t Com
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