OT Interesting video - Page 5 - Cycling Mob: Road Cycling, Mountain Biking and More

01-19-2007, 05:56 AM

Paul Cassel wrote:
> Qui si parla Campagnolo wrote:
>
> >
> > At least it was a diesel truck, the real future of internal combustion
> > engines....
> >
> and source of our current nasty pollution.

Nope, new low sulfer diesel plus smaller, powerful, less expensive to
maintain PLUS diesel-hybrid.
'Our current nasty pollution' is from cars, gas cars, not a relativley
small portion of trucks with diesel PLUS bio-fuels, much easier with
diesel than gas-type.

01-19-2007, 05:59 AM

On Fri, 19 Jan 2007 10:17:04 +0100 (CET), "Bill Westphal"
<[Only registered and activated users can see links. ]> wrote:

>> A monolingual
>> person can get by without ever questioning form or sound and could be
>> imitating his closest peers.
>
>If he lives in a closet, or works at the factory by day and watches
>the idiot box by night. Or the Peter Principle has kicked in. OR he
>just doesn't give a ****. Some great (and ordinary) people just have
>a stunning gap somewhere. The trick is discerning whether the gap is
>from carelessness, or beyond the persons control. Some very smart
>people spendtheir lives fighting that gap, and lose. I think the key
>in this case is that it's just the one word, and has nothing to do
>with anything else.

And he could be better read than social - the common freshman issue of
coming out of high school with a vocabulary picked up from reading
with little feedback from peers on how to pronounce the words
properly. I can still revert to a horrible pronunciation of
'clandestine' without much encouragement.

I've seen my share of tech people that have more reading vocabulary
well into their adult lives than they use with any degree in
conversation. At least most don't intersperse "and, uh" throughout
their speech. If someone speaks in complete sentences, I'll cut them a
lot of slack. And correct them later clandestinely, clandestin, uh, in
private.

Curtis L. Russell
Odenton, MD (USA)
Just someone on two wheels...

01-19-2007, 07:07 AM

In article <1169214960.564613.42370@m58g2000cwm.googlegroups. com>,
"Qui si parla Campagnolo" <[Only registered and activated users can see links. ]> wrote:

> Paul Cassel wrote:
> > Qui si parla Campagnolo wrote:
> >
> > >
> > > At least it was a diesel truck, the real future of internal
> > > combustion engines....
> > >
> > and source of our current nasty pollution.
>
> Nope, new low sulfer diesel plus smaller, powerful, less expensive to
> maintain PLUS diesel-hybrid.

Ridden your bike behind a diesel truck lately? They still suck with
massive output of particulates. There are diesel designs that are very
efficient and clean-burning, but they are not in widespread use. The
University of Minnesota has a diesel development program that has
resulted in diesel engines with very low emissions. I spent a very
interesting hour talking with one of the lead engineers in that project
a couple of years ago.

[Only registered and activated users can see links. ]

> 'Our current nasty pollution' is from cars, gas cars, not a
> relativley small portion of trucks with diesel PLUS bio-fuels, much
> easier with diesel than gas-type.

You can't pinpoint current air quality problems from a single source or
even a single nation. There are lots of contributors. Cars. Trucks.
Coal fired powerplants. Industry.

At this point we are still buying into the illusion of "profit, profit
uber alles" as the mantra for our economic model.

01-19-2007, 10:13 AM

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.

I think you are thinking about a specific application - aircraft
engines. A well-built turbine should come out near twice the
efficiency of a diesel with the same output. But it would cost several
times as much to make.

If diesels were more efficient, we would not use turbines in power
plants, where even tiny efficiency advantages make significant profit
differences.

> 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.

A constant speed, high-RPM case could be made for turbine-electric
hybrids, but if it really would work, I would expect diesel-electric
locomotives to be replaced with turbine-electric.

Austin

> 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.

01-19-2007, 10:54 AM

"AustinMN" <[Only registered and activated users can see links. ]> wrote in message
news:1169230416.589306.95270@11g2000cwr.googlegrou ps.com...

> I think you are thinking about a specific application - aircraft
> engines. A well-built turbine should come out near twice the
> efficiency of a diesel with the same output. But it would cost several
> times as much to make.
>
> If diesels were more efficient, we would not use turbines in power
> plants, where even tiny efficiency advantages make significant profit
> differences.

Have you seen the efficiency of big diesels, as used in eg ships (the 2
stroke scavenging ones)? It's astonishingly high (55%?). Gas turbines plus
steam turbines in a combined cycle manage to beat it, but it's pretty close.

cheers,
clive

01-19-2007, 12:00 PM

Ryan Cousineau writes:

>>>>> But how about this concept:

[Only registered and activated users can see links. ]

>>>> 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.

>> 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.

>> The Wankel is dead!

> E pur si muove:

I don't understand your comment, "and also one moves"?

[Only registered and activated users can see links. ]

It will remain as a boutique experiment and appeal to those who seek to
be different. As a useful engine, it is dead for the reasons cited.
It has not made any advances in IC propulsion and remains a problem
that has not been solved.

Jobst Brandt

01-19-2007, 12:08 PM

[Only registered and activated users can see links. ] wrote:
>
>
> That article doesn't answer my question or say that these people are
> otherwise linguistically skilled. I wonder how many of them spoke
> more than one language. One who masters English and French, for
> instance, must have a keen ear for pronunciation. A monolingual
> person can get by without ever questioning form or sound and could be
> imitating his closest peers. I related the story of the young
> engineering officer who described an impact area as being strewn with
> "derbis" and had in all his life gotten away with it, possibly talking
> to people who knew neither what debris or derbis was.

One of my best friends in engineering school couldn't correctly
pronounce "aluminum." No matter how he tried, it came out "alunimum."
Amazingly, he got a job with Alcoa. I hope he eventually got it right
there!

> I found that so elegant a faux pas that ever since I usually say
> "derbis" among friends and family. I've mentioned that those who were
> among the highest GPA's in college were on occasion not gifted with
> great intelligence but rather good short term memory, persons I would
> not ask to explain a complex concept.

The guy I mentioned was definitely intelligent, and an excellent
problem solver.

Personally, I think memory (whether short or long term), logic, problem
solving, analysis, design or synthesis, artistic skills, auditory
skills etc. are all different aspects of intelligence. A person can
excel at many of them and definitely be considered "intelligent," but
still have deficits in others.

But regarding pronunciation, I think lots of Americans get by simply
because the country is mostly monolingual. As you say, they never need
to develop as much skill with their ears or their voice.

> Just because some great people
> have great leadership skills...

.... or, alternately, skill at standing in front of a microphone and
saying what they're told to say... ;-)

>... we should not expect them to be equally
> skilled in other areas.

Exactly. But that doesn't prevent "nucyooler" from sounding dumb!

- Frank Krygowski

01-19-2007, 12:52 PM

[Only registered and activated users can see links. ] wrote:
>> One of my best friends in engineering school couldn't correctly
> pronounce "aluminum."

and Americans can't spell aluminium!

(;-)

pk

01-19-2007, 01:04 PM

> Ryan Cousineau writes:
>>>>>> But how about this concept:
> [Only registered and activated users can see links. ]

[Only registered and activated users can see links. ] wrote:
>>> The Wankel is dead!

> Ryan Cousineau writes:
>> E pur si muove:
> [Only registered and activated users can see links. ]

[Only registered and activated users can see links. ] wrote:
> I don't understand your comment, "and also one moves"?
> It will remain as a boutique experiment and appeal to those who seek to
> be different. As a useful engine, it is dead for the reasons cited.
> It has not made any advances in IC propulsion and remains a problem
> that has not been solved.

He was paraphrasing Galileo Galilei who, after being convicted of heresy
for disputing that Earth was the fixed center of the universe, is said
to have muttered, "And yet it moves".

[Only registered and activated users can see links. ]

Cute but not exactly germaine to Wankel.
IIRC it's usually 'Eppur si muove' but I'm not an expert
--
Andrew Muzi
[Only registered and activated users can see links. ]
Open every day since 1 April, 1971

01-19-2007, 01:50 PM

Isn't the RX-8 a rotary engine? And I owned a RX-2..2 plugs per rotor,
btw, not one.
[Only registered and activated users can see links. ] wrote:
> Michael Press writes:
>
> >>> But how about this concept:
>
> [Only registered and activated users can see links. ]
>
> >> 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