On Thu, 07 Jun 2007 10:26:40 GMT, Ron Hardin
wrote:

Brian Whatcott wrote:
But that back pressure slows the turbine, just as surely as going through the blades
backwards would. Equivalently, the compressor is doing more work the more you ignite
the fuel. What keeps the turbine from slowing to a stop and then everything just
blowing out both front and back?

If I arrange to share the motive power between compressing input air,
and accelerating exhaust air, the compressor is a load. and
accelerating the exhaust is a load.
The compressor does not normally stop if I supply energy as fuel.
And the exhaust does not normally stop if I keep supplying fuel.

The question is, though, why the combustion products don't just blow
out both ends. _All_ the turbine blades are compressors, from the point
of view of the gasses.


Ah, I see Ron's issue - thinking that a compressor blade is
functionally identical to a power turbine blade. Their curvatures are
different with respect to the airflow, in fact.

But I have spent too much time on this question

Regards

Brian W