Cycling Forums - View Single Post

01-18-2007, 06:48 PM

Michael Press writes:

>>> But how about this concept:

http://www.starrotor.com/Engine.htm

>> After gazing at hundreds of "miracle engine" articles over the
>> years, I've decided to ignore any reports that don't include tests
>> of working models. The only one of those hundreds of designs that
>> gained any traction was the Wankel, and it didn't set the world on
>> fire.

>> That page is way too full of phrases like "...is projected to
>> have...", "...should be...," "...is expected to be..."

> Can you can tell me why gas turbine engines are not practical? They
> have run well in races.

Their thermodynamic efficiency is relatively poor in comparison to the
reciprocating piston engine and the response time is miserable. They
are used effectively in power plants where they run at steady state at
their ideal speed. They did not even come close in railroad
applications where the C&O (for progress) built steam turbines and UP
(the big blow) gas turbine, although I don't know who paid the bill.

http://www.visi.com/~jweeks/centennial/index.html

Can you imagine starting from a traffic light from idle trying to get
up to speed in dense traffic. Aircraft are far better at that, their
propulsion being from a fan in the first place and then at close to
steady speed. The place where there is a cross-over is in helicopters.
They use mechanical power from the turbine to turn the rotor. That is
essential in any high altitude flying. I have not seen a piston
engine helicopter in the alps.

Jobst Brandt

01-18-2007, 06:48 PM	#29 (permalink)
jobst.brandt@stanfordalumni.org Guest Posts: n/a	Re: OT Interesting video Michael Press writes: >>> But how about this concept: http://www.starrotor.com/Engine.htm >> After gazing at hundreds of "miracle engine" articles over the >> years, I've decided to ignore any reports that don't include tests >> of working models. The only one of those hundreds of designs that >> gained any traction was the Wankel, and it didn't set the world on >> fire. >> That page is way too full of phrases like "...is projected to >> have...", "...should be...," "...is expected to be..." > Can you can tell me why gas turbine engines are not practical? They > have run well in races. Their thermodynamic efficiency is relatively poor in comparison to the reciprocating piston engine and the response time is miserable. They are used effectively in power plants where they run at steady state at their ideal speed. They did not even come close in railroad applications where the C&O (for progress) built steam turbines and UP (the big blow) gas turbine, although I don't know who paid the bill. http://www.visi.com/~jweeks/centennial/index.html Can you imagine starting from a traffic light from idle trying to get up to speed in dense traffic. Aircraft are far better at that, their propulsion being from a fan in the first place and then at close to steady speed. The place where there is a cross-over is in helicopters. They use mechanical power from the turbine to turn the rotor. That is essential in any high altitude flying. I have not seen a piston engine helicopter in the alps. Jobst Brandt