OT Interesting video

Michael Press wrote:
In article
. com,
wrote:

Wayne Pein wrote:

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.

Well, let's see... just guessing, since I'm not an expert:

The main thing is probably just the expense of producing them and using
them in cars. Gas turbines need very sophisticated materials for
things like the turbine blades, which operate continuously at very high
temperatures and very high rpm.

Regarding the expense of using them, they are far from being a "drop
in" replacement for a piston engine, since their transmissions would
need much, much more gear reduction. (I don't know about their torque
curves offhand, but some adaptation may be necessary there, too.)
Their exhaust is, I think, much hotter, too.

The high temperatures and extreme rotation speeds might cause problems
in crashes, too, when hot shrapnel might be expected.

All these things mean designers are not working with familiar
territory. They'd be doing their best to anticipate problems, but they
might easily miss something that caused big problems later.

It's interesting to note that, even if you had something that was (say)
20% "better" than a standard piston engine and no more complex, it
would still be a hard sell if it were too "different." Car companies
the world over have billions invested in machine tools and production
lines to produce today's engines. They probably won't like to gamble
on replacing all that.


To tie this into bikes: One of America's technical experts on bikes is
Professor David Gordon Wilson of MIT. He's the lead author of the book
_Bicycling Science_ and former editor of the monthly technical journal
Human Power. And, in his professional life, he researches and teaches
courses in gas turbine design. (Or did - I guess he's retired now.)

See http://www.me.mit.edu/people/personal/dgwilson.htm

- Frank Krygowski

BTW, a lot of people laugh at 43 about his pronunciation of the word
"nuclear", and I did too (quietly) when I joined the nuclear navy and
noticed some highly educated people doing the same, until I figured
out that's the legitimate pronunciation on the east coast, or at least
in parts of it.... never thought I'd be defending him!


It is the same for alot of expressions too They are predominant in separate
regions of N. America. Course Bush is another region on his own.

do you say soda, soft drink, or pop?

sneeker, runner, _______ put your own.

I thought I knew English till an English person said glass ear for my
glacier. Long A.

Wayne Pein wrote:
Ken C. M. wrote:



Ask Chrysler they tried to get one to work in a prototype back in 70s
and it went nowhere fast.


The same fabulously competent Chrysler that had to be bailed out of
bankruptcy by the US gov't?

Wayne


Yeah that would be the one and only. I believe the cars name was going
to be very original the "Turbine". I saw a piece on the History Channel
about it, I nearly fell out of my chair laughing.

Ken
--
The bicycle is just as good company as most husbands and, when it gets
old and shabby, a woman can dispose of it and get a new one without
shocking the entire community. ~Ann Strong

On Thu, 18 Jan 2007 16:40:11 -0500, Ken C. M. wrote:

Michael Press wrote:

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

Ask Chrysler they tried to get one to work in a prototype back in 70s
and it went nowhere fast.

Turbines are actually less efficient and pollute more than modern diesels,
so they're a non-starter for car/truck use.

On top of that, they're expensive, run at too-high RPM, and have a narrow
RPM operating range. They're more suited for constant speed, high load
applications, like generators and aircraft/marine propellers.

Turbines are well suited for aircraft because of their light weight,
compact size, reliability, and relative efficiency. Light weight and
compact size makes for a smaller plane which requires less power, etc.

An Indy race car is a relatively constant speed, high load application,
where light weight and compact size are important too. Thus Granatelli's
effort in the 60s, which would have won if not for a broken fuel pump.

Matt O.

I was watching a new tv show "Living with Ed" (Begley) last sunday and
Ed visited Jay Leno who pointed at a car he is having built, a diesel
turbine, so he can run it on soy diesel.

http://www.jalopnik.com/cars/sema/th...car-211247.php

In article
,
Matt O'Toole wrote:

On Thu, 18 Jan 2007 16:40:11 -0500, Ken C. M. wrote:

Michael Press wrote:

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

Ask Chrysler they tried to get one to work in a prototype back in 70s
and it went nowhere fast.

Turbines are actually less efficient and pollute more than modern diesels,
so they're a non-starter for car/truck use.

On top of that, they're expensive, run at too-high RPM, and have a narrow
RPM operating range. They're more suited for constant speed, high load
applications, like generators and aircraft/marine propellers.

Turbines are well suited for aircraft because of their light weight,
compact size, reliability, and relative efficiency. Light weight and
compact size makes for a smaller plane which requires less power, etc.

An Indy race car is a relatively constant speed, high load application,
where light weight and compact size are important too. Thus Granatelli's
effort in the 60s, which would have won if not for a broken fuel pump.

Thanks.

--
Michael Press

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.

Interestingly, the Wankel first found real fertile soil at NSU in
Neckarsulm (from which the name arises) just north of Stuttgart where
I was working at the time. n R&D engineer came rolling in into our
shop at Porsche to demonstrate this new concept.

At the time I mentioned to the engineers to mark my words, that this
engine will not survive, to their utter amazement... and that of all
the others who wanted to believe in it. My thermodynamics Professor
had shown us running rotary prototypes in the lab from years past and
explained why they cannot work. They all have the same feet of clay
as they address only the mechanical part of the machine and fail to
see that this is a heat engine and thermodynamics its main focus.

Essentially one spark plug for multiple rotating combustion chambers
is what kills it. At the spark plug, temperatures in the 1000's degF
occur if the engine has any reasonable efficiency, while the intake
zone is below freezing (carburetor icing). Both areas remain a steady
state.

It's the reciprocation that makes it work. We use aluminum pistons in
a mundane engine block with steel valves that see temperatures from
freezing to flaming in one cycle. The average temperature when seen
through a boundary layer of gas is mundane. Meanwhile the Wankel
burns up! To make it work, compression had to be low giving poor
performance, requiring higher engine speed to make up for that poor
performance. The result is a short lived machine with poor fuel
economy.

When I read about propelling bicycles with the arms in a sprint or why
mechanical stress relieving doesn't work, I recall these engineering
moments where conventional thinking stymies understanding. You can be
sure that I found no takers at Porsche. Professor Kays at LSJU had it
right, although I believe his class failed to see the importance of
his lecture and that was years before Felix Wankel presented his
engine. That's often the way school is.

The Wankel is dead!

Jobst Brandt

Bill Westphal writes:

BTW, a lot of people laugh at 43 about his pronunciation of the word
"nuclear", and I did too (quietly) when I joined the nuclear navy and
noticed some highly educated people doing the same, until I figured
out that's the legitimate pronunciation on the east coast, or at least
in parts of it.... never thought I'd be defending him!

http://en.wikipedia.org/wiki/Alfa_class_submarine

That's interesting. What do these people say when they discuss
nucleation and that the nucleus of an atom does thus and so. It seems
to me to be much line the people who cannot say length or strength,
saying lenth and strenth instead. I'm nut sure they have the musical
ear to discern the difference.

Jobst Brandt

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

Bill Westphal writes:

BTW, a lot of people laugh at 43 about his pronunciation of the word
"nuclear", and I did too (quietly) when I joined the nuclear navy and
noticed some highly educated people doing the same, until I figured
out that's the legitimate pronunciation on the east coast, or at least
in parts of it.... never thought I'd be defending him!

http://en.wikipedia.org/wiki/Alfa_class_submarine

That's interesting. What do these people say when they discuss
nucleation and that the nucleus of an atom does thus and so. It seems
to me to be much like people who cannot say length or strength, saying
lenth and strenth instead. I'm not sure they have the musical ear to
discern the difference.

Jobst Brandt