Global Warming hits the Eastcoast !

[martin griffith]

On Mon, 13 Feb 2006 13:47:50 -0700, in sci.electronics.design Jim

snippity doo dah

Will we want "IN" ?

But please accept Rich the <insert expletive of your choice> as a
permanent and irrevocable resident ;-)

...Jim Thompson

Well, maybe not, they will just want "OUT" of the US,


martin

 

[Pooh Bear]

Well, even that is somewhat higher than I recall, because the steam-turbine
example above is for one engaged in generating electricity.

However, my memory isn't that precise, and is getting less so, and
technology no doubt has improved. A turbine's practical efficiency isn't a
factor of theoretical heat cycles as much as it is a matter of how much heat
and erosion it can tolerate.

I came across that figure in a thread in another ng recently. Apparently up from
35% only a few years ago. There's been quite a lot of new generation built
recently in the UK using natural gas which may explain the improvement. It also
entertainly shows how short term thinking ( natural gas is cheap - so lets burn
it ) can blow up in your face !

In regard to gas turbines, I visited Pratt & Whitney's engine division
decades ago on a press junket, to hear them tell us how they'd raised the
operating temperature of a jet engine by roughly 100 degrees F, from 2,200
to 2,300 degrees. I remarked that didn't really sound very impressive. An
old P&W engineer sitting next to me said, "Son [I was much younger then
<g>]," there are men here who would sell their grandmothers for another
hundred degrees."

A friend of mine works in aeropsace design. I'm awed by the tricks they use to
cool those turbine blades. They would melt otherwise !

Graham

 

[carneyke]

Maybe you are right, but when they converted to the catalytic convertor
and raised the operating temperature, the engine compartment through
off much more heat. I guess you are right, putting it in a common sense
way (either the heat went up the tailpipe or given off by the engine
compartment). I didn't take High School Physics, went the electric shop
route with the other "sparkies". Made a damn good living at it too....

 

[Jim Thompson]

It actually was worse. The 1977 280Z had injection into the
(straight-6) manifold at multiple points with "air-door" control.

Instrumentation was a combination of a positive displacement flow
meter plus a calibrated float in the tank... a precursor to modern
"miles-to-go" systems... with a _discrete_logic_ "microprocessor"
doing all the data churning ;-)

...Jim Thompson

Sorry but I remembered poorly. Thinking about it, I was never below
55MPH, so it's possible with that manifold style injection the MPG got
better at lower speeds. But 65MPH was definitely better than 55MPH.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

Yellow Journalism now has a new definition... guess what it is?

 

[Ed Huntress]

It actually was worse. The 1977 280Z had injection into the
(straight-6) manifold at multiple points with "air-door" control.

Instrumentation was a combination of a positive displacement flow
meter plus a calibrated float in the tank... a precursor to modern
"miles-to-go" systems... with a _discrete_logic_ "microprocessor"
doing all the data churning ;-)

All else being equal, light cars typically get their best mileage at just
over 50 mph, and heavy ones somewhere between 45 and 50 mph. There are many
factors involved, including engine design.

The 280Z had a pretty advanced FI system -- yours might have been an early
Bosch L-Jetronic -- and it was fairly slick. Even so, though, to get peak
mileage at 65 mph, where drag has already become a significant factor,
speaks more to how lousy the system worked at lower speeds. <g> The
semi-sporty nature of that engine may have involved a lot of valve overlap
or large exhaust valves, both of which knock your low-rpm, low-load mileage
to hell.

In any case, even getting peak efficiency at 50 mph tells us not that the
car has high efficiency at higher speeds, but that the car has poor
efficiency at lower speeds, mostly for the reasons we've discussed.

 

[Ed Huntress]

Maybe you are right, but when they converted to the catalytic convertor
and raised the operating temperature, the engine compartment through
off much more heat. I guess you are right, putting it in a common sense
way (either the heat went up the tailpipe or given off by the engine
compartment). I didn't take High School Physics, went the electric shop
route with the other "sparkies". Made a damn good living at it too....

Well, that beats what's happened in *my* field lately. <g>

As a couple of people have intimated, the heat from the cat is just heat (or
unburned fuel) that would have gone straight out the tailpipe, without the
cat. It's true that today's engines burn more inside the engine and less
goes out as heat or as unburned hydrocarbons. But not that much as a
percentage, overall. Some of that which *doesn't* go out the tailpipe goes
off as waste heat from the cat (as you've identified) and some goes off in
engine cooling (as you've also identified). But some very small portion
winds up as power at the wheels -- where it then gets turned into heat of
friction. d

It all goes out as heat, one way or another, or as polluting, unburned
hydrocarbons or products of them (such as carbon monoxide, which will burn).
'Ain't no free lunch.

 

[Ken Smith]

On Sun, 12 Feb 2006 22:57:32 +0000, Ken Smith wrote:
[snipped global warming hysteria rants]

... we
have concluded that it is best to "play it safe".

First, who's "we"? Got a mouse in your pocket?

No, "we" means evereyone else but you. We are conspiring against you. I
thought you'd figured that out.


[...]

Is that an experiment we really want to undertake?

We are doomed to be part of the experiment no matter what we do. We will
either continue to make more and more CO2 or we will reduce it. Our cars
can average 15 MPG or 30. In either case we can't back up and try the
other way to see if it comes out different.

 

[Ken Smith]

25 years ago when every town sprayed for mosquitos you could camp /
hike / hunt anywhere without being infested with ticks. Then all
pesticide usage was stopped (early 1980's). Today the Northeast is
covered with ticks making most forested areas useless other than taking
pictures of or painting. I will admit the migratory bird hunting has
gotten better, although the deer are covered with ticks when you get
one. I am not advicating the use of pesticides but some things done in
the early 80's haven't worked out very well.

It depends on who you are. I'm sure the ticks like it a lot better.

DEET AKA N,N-diethyl-m-toluamide is your friend. It seems to work on
ticks along with the others that it is advertized to repell.

 

[Ken Smith]

Maybe, but it's a lot less sad than the scenario where the fanatics
install a global totaliarian dictator to shoot people who light a fire
or fart without permission.

Are you saying that Harry Whittington farted?

Now it makes sense.

 

[Ken Smith]

Grahm,
Hot is hot, no matter how you "analyze" it. Today's cars generate much
more heat and there is many more cars than 30 years ago. No science
involved Sherlock, just plain old common sense,

This is wrong. Todays cars use less gas partly because they make less
heat than those of the 70's

 

[Ken Smith]

Naaah! I find 340 HP and 333 ft-lb just right ;-)

So what kind of motorcycle is it?

 

[Ed Huntress]

Sorry but I remembered poorly. Thinking about it, I was never below
55MPH, so it's possible with that manifold style injection the MPG got
better at lower speeds. But 65MPH was definitely better than 55MPH.

It would be interesting to see how that worked out on a complete curve, but
there are so many factors involved in a car that has anything special about
it for performance that it wouldn't tell us much about the generalities.

My '58 Alfa Romeo with full-race Tom O'Brien motor would hardly run at all
below 40 mph. I think it sprayed raw gas out of the tailpipe at that speed.
<g>

 

[Rich Grise]

Gee, you must be coming from an awfully polite newsgroup. <g>

FWIW, most of the fuel you burn in your car goes out the tailpipe. A
super-efficient spark-ignition engine turns something like 24% of its fuel
into motive power (if my memory of this number is not accurate, someone
please correct me; I haven't looked it up for years). Of that, something
like 60% makes it to the drive wheels. So a spark-ignition-engined car, on a
good day, delivers somewhere around 15% of the thermal potential of the
fuel, as motive power to the wheels.

It doesn't get a lot better with other engine types. A large, efficient,
stationary diesel is good for something like 28% at the shaft. The number is
similar for a huge, stationary, multi-stage steam turbine. And, believe it
or not, also for a Stirling, running with helium or hydrogen for a working
fluid, at very high internal gas pressure and with a high-efficiency heat
exchanger at each end.

Sucks, doesn't it? And that's on a good day. d

Speaking of losing memory neurons, I seem to recall seeing a sort of
diagram, back in the '50's, when they had flat-head straight 6's, that
something like 2% of the potential power in the fuel actually got to the
wheels.

There were HUGE thermal losses, and friction, and yadda yadda yadda...

Thanks!
Rich

 

[Rich Grise]

Well, even that is somewhat higher than I recall, because the steam-turbine
example above is for one engaged in generating electricity.

However, my memory isn't that precise, and is getting less so, and
technology no doubt has improved. A turbine's practical efficiency isn't a
factor of theoretical heat cycles as much as it is a matter of how much heat
and erosion it can tolerate.

I came across that figure in a thread in another ng recently. Apparently up from
35% only a few years ago. There's been quite a lot of new generation built
recently in the UK using natural gas which may explain the improvement. It also
entertainly shows how short term thinking ( natural gas is cheap - so lets burn
it ) can blow up in your face !

In regard to gas turbines, I visited Pratt & Whitney's engine division
decades ago on a press junket, to hear them tell us how they'd raised the
operating temperature of a jet engine by roughly 100 degrees F, from 2,200
to 2,300 degrees. I remarked that didn't really sound very impressive. An
old P&W engineer sitting next to me said, "Son [I was much younger then
<g>]," there are men here who would sell their grandmothers for another
hundred degrees."

A friend of mine works in aeropsace design. I'm awed by the tricks they use to
cool those turbine blades. They would melt otherwise !

I was on a document coding project where somebody was suing somebody else
about inferior turbine blades. They're like, a single crystal of titanium
that's grown in a mold, and if you drop one on the floor, you have to
scrap it. I think maybe even if you touch it with bare fingers, you have
to scrap it. It seems a new jet engine is about $2,000,000.00, but an
overhaul, where they basically replace all of the turbine blades and
bearings, is only about $250,000.00. Or, was in the 1990's.

Cheers!
Rich

 

[Rich Grise]

Airbus quote 3 litres of fuel used per 100 pasenger km - approx
equivalent to ~ 50 UK mpg or ~ 40 US mpg. Better than a car with a
sole occupant at least.

Of course the long distance of many airline flights means a large
amount of fuel is used. Chances are most ppl would think twice about
the need to visit their their destination if they had to drive.

I've been on a couple of excruciatingly long overseas flights - like,
14 hours of cruising across the Pacific[1], and I wonder where the hell
they keep all of that fuel? The fuel lines on those engines are, like,
2" (5 cm) or so in diameter! (well, the ones I've seen on USAF fighter
jets.)

Thanks!
Rich
[1] I took along a copy of Frank Herbert's "Dune", and it turned out
that watching the ocean go by in the moonlight was measurably less boring,
and infinitely more comprehensible! ;-)

 

[Rich Grise]

I'd be willing to bet real money that you just pulled that number out of
your ass.

I'm not gonna take that bet, 'cause you'd win. ;-) Did you know that in
The Netherlands, that same expression translates to "sucked it out of your
thumb"? ;-P I explained to my coworker, a Hollandaise guy, ;-) that
sometimes it's "pulled it out of the air". ;-) He also taught me
"zaadvragende ogen". <leer, snort> ;-P

Cheers!
Rich
--- <- munged siggie thingie, to promulgate my campaign.
Elect Me President in 2008! I will:
A. Fire the IRS, and abolish the income tax
B. Legalize drugs
C. Stand down all military actions by the US that don't involve actual
military aggression against US territory
D. Declare World Peace I.

 

[Rich Grise]

While smoking pot ;-)

Does that disturb your delicate little puritan sensibilities?

Thanks!
Rich
--
Elect Me President in 2008! I will:
A. Fire the IRS, and abolish the income tax
B. Legalize drugs
C. Stand down all military actions by the US that don't involve actual
military aggression against US territory
D. Declare World Peace I.

 

[Michael A. Terrell]

Yeah, I am a little behind the times (Climate Change terminology being
in Vouge). On a serious note, this summer I read an article on
automobile registration in the USA. In 1975 (year I graduated from High
School) there were roughly 130 million cars registered. Today it is
around 280 million cars (I may be off on these numbers slightly).
Anyway, if you remember, cars ran at 160 degree F back then and today
they run at 200 degree F. They also have that hot little catalytic
converter. I truly believe, the doubling of cars (with catalytic
converters) and the 25 % increase in engine temperature must have some
effect on the atmosphere. I know this has been kicked around but the
article really opened my eyes to the heat generated by cars. I guess
this is a case of fixing one problem and creating another. Take Care
.....

200°F is NOT a 25% increase over 160°F. What a useless LUSER.
--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

 

[Michael A. Terrell]

=================================

Amongst the most polluting of energy hogs are aircraft engines.

Ban all motor vehicles and airliners and let the World slow down!

Great idea, Reg. We'll start with your neighborhood. No
electricity, no running water, no food deliveries, no sewage system. No
high speed transportation also means little or no medical care, The
world won't "Slow down", but billions of people will die. Maybe we
should ban morons first?


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

 

[Steve R.]

Don Klipstein wrote:
(snip)

Global warming does not necessarily imply less snow, since warmer air
holds more moisture than colder air, allowing it to deliver more snow.
Only when global warming brings a particular location above the freezing
point, does it imply rain instead of snow. Expect places that normally
have had dry, cold winters to have warmer winters with lots more snow.
Till it gets lots warmer.

My daffodils started blooming in January, here on the west coast of Canada!

Steve R.