Royce Wise wrote:

Paul, care to answer this post from another newsgroup?
Royce

"S. Ramirez" wrote:

<snip>

The only place a turbine makes any sense is up high, real high.  A turbine
makes no sense at the altitudes  we fly in small experimental airplanes.

...

I'd rather cruise along with a Lycoming (or maybe a Subaru?) and be able

to

fly past a few fuel pumps.

dd

<unsnip>

Does anyone know why a turbine is more efficient at higher altitudes than at
lower altitudes?  Just curious.

Thanks.

Simon Ramirez, Aerocanard Builder
Oviedo, FL USA

The specific fuel consumption does not change. Pounds of fuel burned
per pounds of thrust generated. Aero drag is
lower at high altitudes. Thrust falls off but not as fast as aero
drag falls off so the airplane goes faster. Thrust does not fall off
as fast as it would but for the ram effect. This  increases pressure
in the inlet at the higher speeds. Sort of like how a ram jet works 
to a minor extent.

Paul Lamar
 
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