"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.

Umm...that's what he said: "...real exotic materials".


It may take a significant investment,
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
using the Rotax 914 engine which is a very popular GA engine. A small
turbine may sound far fetched now, but I am sure GPS also sounded far
fetched 20 years ago, but became commonplace after heavy military
investment.

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.

It's not the physics, it's the COST of those PHYSICS.