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[P]
(Nearly) Pollution-Free Transit

By jd in Technology
Fri Apr 06, 2001 at 08:38:01 AM EST
Tags: Science (all tags)
Science

Instead of the mindless bickering back and forth over whether Global Warming is real, I'm going to try an alternative track. Let's pretend that pollution is a serious problem, and try to tackle it. (Let's ignore, for the moment, what it's a problem -for-, as that simply gets us back to square one.)

As transit is one of the largest sources of pollution, I propose we discuss ways to reduce or eliminate such pollution. Below is one idea of mine to do just that...


The domestic car is probably one of the easiest offenders to tackle, so I'm going to start there.

First, nitrogen dioxide, which when released into the atmosphere, becomes nitric acid, is a simple enough one to cure. Nitrogen doesn't just spring into existance, after all. If it doesn't enter the system, it won't leave the system. But how to stop it from entering the system in the first place?

One way (and it's not necessarily the best or the most efficient for this purpose) is to simply have a charged mesh at the front of your air intake. The electrons around oxygen are much easier to displace than those around nitrogen, leaving the oxygen pairs charged and the nitrogen pairs uncharged.

Then, place a junction in the air intake, with one of the paths having a charged plate next to it. The charged air molecules (including the oxygen) will turn down that path, leaving the nitrogen and other uncharged particles to go the other way.

This would greatly enrich the oxygen to the engine and almost eliminate the nitrogen content, thereby eliminating any nitrogen-based waste products.

Then, there's the waste heat the engine is producing. That, in itself, isn't a problem. The problem is that that is energy you can't use, and therefore you end up burning additional fuel to make up for it.

Heat is a real problem, since it's a natural result of any exothermic reaction. (That's why it is -called- an exothermic reaction! :) However, both Classical Physics and Quantum Physics come to our rescue. (Phew!) In classical physics, you must always satisfy the conservation of momentum AND the conservation of energy, where momentum (M) and kinetic energy (ke) are defined as: M = m.v, ke = m.v^2 (where m = mass and v = velocity).

Because momentum is a function of velocity, whereas kinetic energy is a function of velocity squared, not all values are going to work. Some situations are simply impossible. All you have to do is make the engine a system where the "surplus" components needed to satisfy both equations are nearly zero. The better you can do that, the less waste heat you will produce.

Now, we get into the quantum physics. These systems are not continuous. They operate in fixed-size steps, called quanta (greek for 'enough'). The energies of any given region will be quantized and can never have any values outside of that. To ensure that we get the results we want, rather than some alternative solution to the classical equations, we must ensure that the solution we want satisfies the conditions imposed by quantum mechanics, and that ALL alternative solutions to the classical equations would violate these conditions.

Now, we move from the engine to the exhaust system, where turbulence and other chaotic effects reside. Grooved surfaces break up turbulence, and may improve the flow of air.

On the theme of air-flow, we now go onto aerodynamics. Near-vertical front & back, uneven underbody and sod all stream-lining. A brick would be only marginally worse. You need to push the air away without transferring 90% of your engine's output to it. If you have the car's sides deformable, and push the air left or right, you can meet all those requirements and improve handling AND performance, at the same time. ("Classical" aerodynamic aids rely on "ground effect" - read: sucking the car to the road. But this seriously throws all efficiency to the wind. On the other hand, using the air to "pull" a car to the left or right would not reduce efficiency, whilst still assisting the car in turning.)

Last, but by no means least, I'll tackle gearing. An engine is tuned to produce optimal performance within a particular rev band. (In racing, this band is extremely narrow.) The driver then uses the gears to keep the car, as far as possible, within that band and (ideally) at the point of peak performance. The more gears you have, and the closer they are together, the better you can do this, and the better the millage. (This is why manual cars, which have 4 or 5 gears, all do better than automatics, where 3 gears is normal. You just can't keep the car at it's optimal point, on only 3 gears.)

However, even 5 gears is a very small number. What you -really- need is a continuous gear ratio, with the car's engine at a fixed number of revs. Then you can tune the car to that spike, and you are always going to get the best out of the engine.

How to do that, though? Simple. The gear ratio is simply the ratio of the radii of the two wheels used for the gears. If one of those wheels is expanding/contracting, depending on the speed of its rotation, you'd have continuous gears. An overly-simplistic way to do this would be to have one "wheel" simply be wheel segments that are pulled together by some sort of spring. Inertia will force the segments apart, when you accelerate, and the restoring force of the spring would force the segments back closed, when you brake.

This is by no means a "perfect" car, and it is doubtful it would even work, as written above. But these ideas demonstrate that there are ways to improve the design of vehicles, at negligable cost or effort, in a way that would improve efficiency and reduce pollution.

At this point, I'd like to shut up and encourage others to contribute their own thoughts on how to improve vehicle design. (Comments on the above ideas are also welcome.)

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Poll
Improving transit is...
o Pointless. We'll invent teleportation soon. 2%
o Stupid. The earth is over-populated as it is. 3%
o Naive. It assumes that the "problem" is worth solving. 2%
o Already done. It's called "the train/tram/bus". 29%
o Intriguing. But hybrid and electric cars solve it anyway. 20%
o Impossible. Too much money is invested in inefficiency. 9%
o Fascinating. I've submitted my own design on how to do this. 11%
o Bizare. I'm off to feed my pet giant vampire bats. 19%

Votes: 81
Results | Other Polls

Related Links
o Also by jd


Display: Sort:
(Nearly) Pollution-Free Transit | 79 comments (72 topical, 7 editorial, 0 hidden)
You want pollution free transit? (4.20 / 10) (#1)
by Anonymous 242 on Fri Mar 30, 2001 at 03:47:47 PM EST

Walk or take a bicycle. Those options cost much less to insure, park, and maintain.

A Stray Thought... (3.75 / 4) (#8)
by Paradocis on Fri Mar 30, 2001 at 04:16:22 PM EST

Your post got me thinking: The energy from walking or riding a bike has to come from somewhere. Food. Eating also produces waste: methane, feces, etc. Theoretically, you're still polluting, it's just alot more efficient and smaller scale because there isn't the 2000+ lbs overhead of an automobile. If everyone were to tie a team of horses to their cars to have them pull it, I'd wager the pollution would be just as bad, if not worse.

(-8

Sorry, I couldn't resist...


-=<Paradocis>=-
+++++++++++++++++++++
"El sueño de la razon produce monstruos." -Goya
+++++++++++++++++++++


[ Parent ]
efficiency, though (3.00 / 1) (#11)
by fuzzrock on Fri Mar 30, 2001 at 04:24:24 PM EST

MY impression from classes was that the energy efficiency of organisms is way way higher than that of machines. Several orders of magnitude, maybe. Sure, we give off wastes, but a lot more of our intake goes to useful tasks than the intake of a car.

[ Parent ]
I'd have to see the numbers (none / 0) (#25)
by weirdling on Fri Mar 30, 2001 at 06:26:47 PM EST

First, a human on a bike can sustain an average of 15 MPH, or enough to get me to work in an hour. The car will be on the road 20 minutes. During this time, the human will pump out quite a volume of CO2 simply because he is running a higher metabolism. This is the parasite pollution, the pollution put out simply because the device is working. The car only puts out 20 minutes' worth of parasite pollution. Now, IIRC, humans average 100 calories/2.5 miles on flat land. Gasoline contains, it seems (nobody has KC/gallon on gas anywhere), about 30.2x10^3 KC/gallon. My car gets 25MPG on the trip, in other words, uses .6 gallons. The human on a bike would use 600 KC on the trip, and the car would use 18,420 KC. Now, my car generates 200 HP and achieves an average speed of 45 MPH on the trip, with a lot of starting and stopping. So, it seems the car is three times less efficient but three times faster, which means, for the speed, that it is much more efficient. In order to beat a human, you'd have to make just 75MPG on the same commute, and I had a motorbike that did that when I was in college.
Of course, humans suffer badly when they hit hills or have to start and stop, but that's another story...

I'm not doing this again; last time no one believed it.
[ Parent ]
CO2 from humans (5.00 / 4) (#27)
by Anonymous 6522 on Fri Mar 30, 2001 at 08:23:12 PM EST

The CO2 in your can exhaust is the result of burning things that have been underground and out of the environment for millions of years. It has been locked away for so long that it can be considered new to this environment, and thus pollution. Not to mention all the other stuff in the exhaust.

The CO2 that you exhale is the result of metabolizing things that were, in the recent past, plants. During photosynthesis these plants take your exhaled CO2 and turn it back into something that you can metabolize.

[ Parent ]

Carbon cycle. (5.00 / 1) (#38)
by physicsgod on Sat Mar 31, 2001 at 06:00:21 PM EST

We could easily get cars into the carbon cycle by changing fuels to something biological, i.e. ethanol.

--- "Those not wearing body armor are hereby advised to keep their arguments on-topic" Schlock Mercenary
[ Parent ]
Re: Carbon cycle (5.00 / 1) (#44)
by superflex on Mon Apr 02, 2001 at 11:06:50 AM EST

That would be very cool, but we'd probably want to start planting some more trees. Or stop cutting them down. Or both. Come to think of it, we should probably do that anyways...

Argonne National Labs has all kinds of info on using alternative fuels in transportation, including ethanol.

[ Parent ]

Efficiency problems (none / 0) (#58)
by weirdling on Tue Apr 03, 2001 at 12:36:34 PM EST

Ethanol and most other bio-mass fuels are only about 1% efficient at converting sunlight. Far better to try solar cells, but they, too, won't be efficient enough to drive our current economy. We are in a situation where a modern society needs more energy than sunlight incident to its area.

I'm not doing this again; last time no one believed it.
[ Parent ]
Three things (5.00 / 1) (#46)
by weirdling on Mon Apr 02, 2001 at 12:42:24 PM EST

First, the CO2 coming from fossil fuels at one time was in the atmosphere. The biosphere can handle it, obviously.
Second, the food humans consume is generated using fossil fuels to propel tractors and all manner of other farm implements.
Third, even supposing human power could address the transport issue, it cannot, of course, address heating, cooling, running computers, whathaveyou, so it isn't likely to make a huge difference, as only 6% of the world's budget of CO2 is made in cars.

I'm not doing this again; last time no one believed it.
[ Parent ]
CO2 (none / 0) (#51)
by Anonymous 6522 on Mon Apr 02, 2001 at 05:51:23 PM EST

1. Yes, at one time it was in the atmosphere, but it hasn't been there for a long time. The biosphere could handle it, but it just might make the planet a bit less comfortable and a bit harder for us to live here. It would change the environment.

2. That's not my point. The food we eat doesn't need to be made using tractors, etc. To me, they are in the same class as cars.

3. Again, not my point. I was just saying that your breath is not pollution, and your car's exhaust is, so you cannot compare the two as equals.

Anyway, theoretically we could power all the things you mention using human power. We'd just need alot of treadmills hooked up to generators.

[ Parent ]

Ok, let's analyse this (5.00 / 1) (#52)
by weirdling on Mon Apr 02, 2001 at 06:31:29 PM EST

A human puts out about three-quarters of a horsepower peak. Generally, about a third of a horsepower is sustainable, and that for limited time. So, a horsepower is around 700 watts, so that's around 233 watts. The limited time I referred to is around four hours, so we can expect your average human to make 933 watt-hours a day, or about 1 kwh. Now, a light bulb burning for a day, ten hours at 100 watts, is about what that human can power. Certainly, it cannot power the peak requirement of a transport vehicle such as a pickup, in the vicinity of 80hp for a small one. That would take 240 humans simply to get food to market in a timely manner. Getting it there more slowly is possible, but the amount of food that will be eaten by the transporters is hideous.
Now, to anyone who has done farming, this is directly applicable. The huge population densities evident in the modern world are precisely because of the scale of farming made possible by the number of tractors employed. Farming is an energy-intensive occupation. It takes a lot of energy to plow a field (80 HP for a six-bottom spade plow at 2 MPH), it takes a lot of energy to move stuff from here to there, it takes a lot of energy to maintain cattle, etc, in cold weather, a lot of energy to heat crops against freezing, a lot of energy to pump water to irrigate them.
If this land were put into production by hand-cultivation, the results would be disastrous. It would significantly reduce yield to not use modern fertilizer (energy intensive to produce), modern seed (energy intensive to research), modern plowing, planting, and cultivating (worker-intensive to do), and would result in, essentially, eating the profits. One man, by himself, with no animal aid, can produce enough food to feed perhaps a tenth of a person beyond what he and his family eats. One man, with modern equipment and processes, can feed thousands.
As to using animals, while humans do produce methane, they do it on nowhere near the scale that ruminants (cows, horses, pretty much anything that eats grass) do. So, with the latest study I've seen indicating that methane is much more to be feared, it seems that using animal power is potentially worse for the atmosphere.

I'm not doing this again; last time no one believed it.
[ Parent ]
That last line... (4.00 / 1) (#56)
by Anonymous 6522 on Tue Apr 03, 2001 at 11:53:04 AM EST

...was ment as a lame joke. I realize that there is no way to produce the power we use now with people running to power generators.

***lame joke alert***

Yeah, the amount of food that would be eaten by people taking food to market would be hideous compaired to the amount of food eaten by the pickup truck.

[ Parent ]

Oh, yeah (5.00 / 1) (#53)
by weirdling on Mon Apr 02, 2001 at 06:35:40 PM EST

CO2 is CO2 and the source shouldn't be considered. That CO2 put out by humans is primarily from plant sources does not negate the amount of CO2 put out by machines which are creating the food, and also points out a primary flaw in most anti-CO2 rants, which is to say that planting more trees is never considered. Such a simple, straightforward solution, already underway for other reasons here in the US, is being ignored in favor of draconian behavior modification.

I'm not doing this again; last time no one believed it.
[ Parent ]
For Gosh Sakes (none / 0) (#57)
by Anonymous 6522 on Tue Apr 03, 2001 at 12:10:36 PM EST

Where would we put that many trees?

That the CO2 put out by humans is primarily from plant sources does not negate the amount of CO2 put out by the machines which are creating the food, yes, but the exhaust from the machines can be considered new CO2 to this environment. That CO2 will result in environmental chages, be it global warming or something else.

[ Parent ]

Time to Work (4.00 / 1) (#32)
by paulT on Sat Mar 31, 2001 at 09:34:21 AM EST

While a car can be a fast commuter vehicle a lot depends on the how much traffic there is. For example I have gone to work in the downtown of my city in my car during rush hour, in my car at 4 AM, on foot, and on my bike. My car during rush hour is around 30 minutes and and is much more if you count finding a parking space and the 5 or 10 minute walk from there to work. At 4 AM the trip is about 5 minutes and I can park in front of the building. The walk is about 40 minutes. On my bike the ride is about 15 minutes and I can park in front of the building.

I also I ride all over the city and have found I can get pretty much anywhere in less than hour regardless of the time of day and level of traffic. I do have to grant that the city I live in, Edmonton, Alberta, Canada, has an abundance of wide easily ridable streets.

All that said cars have their place. We have ours for trips to the mountains (up to 20 times a year) and trips in the city where a bike would be impractical due to time constraints or weather.

My wife commutes by bike in the winter but it does take a special breed to ride a bicycle in a blizzard. I winter commute by public transit which take me about 25 minutes to get to work.<br
The bottom line for me is the car is generally a very poor commuter vehicle compared to the available alternatives.



--
"Outside of a dog, a book is probably man's best friend; inside of a dog, it's too dark to read." - Groucho Marx
[ Parent ]
more on bike commuting (1.00 / 1) (#75)
by persimmon on Fri Apr 06, 2001 at 08:59:57 PM EST

Living in a household where I don't have a car, I'd concur that cars do have their place. It's a much smaller place than most people give it, though. I go to school, to the library, off for errands, grocery shopping, and most other places on my bike.

Obviously you're not going to go delivering furniture or moving your friend's apartment on a bike, but most trips don't require the transportation of more than a person and some smallish objects. Bikes can be outfitted as safe commuter vehicles with visibility devices and carrying devices at a much lower cost than a second vehicle, and the lower traffic in bike paths and lanes often means a faster commute. My dad has a 3-mile commute to the University, and it takes about 10 minutes longer by car than bike, counting parking time for both. It's a lot more fun on a bike, too.

But then, I'm a hereditary bike nazi, and I live in a small city. Not everyone has the luxury.
--
It's funny because it's a blancmange!
[ Parent ]
Ahem, maybe I'm going mad but.... (none / 0) (#61)
by eWulf on Fri Apr 06, 2001 at 09:05:28 AM EST

18,420 \ 600 = 30.7 times less efficient. I don't know what speed has got to do with it either. Sorry.

[ Parent ]
you forget (2.00 / 4) (#17)
by jeanlucpikachu on Fri Mar 30, 2001 at 05:21:05 PM EST

if there's long distances to go, walking or bike riding would be invaluable to many of the fatasses riding in their SUVs. How many fat peasants do you see in China? (chinese are bike happy, many more bikes than cars...)

--
Peace,
Capt. Jean-Luc Pikachu AIM: jeanlucpikachu
[ Parent ]
Pollutants (4.16 / 6) (#2)
by ucblockhead on Fri Mar 30, 2001 at 03:52:15 PM EST

If you are going to mention "Global Warming", then you have to treat CO2 as a pollutant. That makes you task much, much harder.

But anyway, a better solution is to take a more radical step, such as burning hydrogen or methane rather than gasoline. Gas is a very dirty fuel.

Also, electric cars have their uses, though you've got to bear in mind that these only move the problem. This is also true for things like hydrogen burning cars. If you use electricity to get hydrogen from water, and then burn this, giving only water as an exhaust, you still are not "non-polluting" if the electricity used was generated by a coal-burning plant.


-----------------------
This is k5. We're all tools - duxup

/in theory/ electricity can be made non-polluting (4.33 / 3) (#5)
by Anonymous 242 on Fri Mar 30, 2001 at 04:04:06 PM EST

Aside from solar and wind power, geothermal power and whatever they call the method that uses the differential between surface water and the deep water in the ocean can be made pollution free. Although that last (which is also the most promising) does create fresh water which could well be considered a pollutant when the power plant is in the ocean.

I do agree with your points though. One has to be careful to not just push the problem out to the suburbs with the big coal-burning plants.

I think the biggest part of the problem is people not living close to where they work and do their shopping and what not. Driving an SUV ten or twenty miles to the closest (or best) grocery store takes a heck of a lot more energy than walking over wagon in tow. I can only imagine how much cleaner the air would be here in Cincinnati without bumper to bumper traffic on the freeway during morning and evening rush hour.

Of course to change that portion of the problem would mean that USAians would need to change their suburban lifestyles. That change is almost inconcevably difficult to push through this side of an extreme environmental emergency.

[ Parent ]

Uh, problem (none / 0) (#22)
by weirdling on Fri Mar 30, 2001 at 06:02:37 PM EST

First, it is easily demonstrable that renewable energy systems do not work. I've included a simple analysis at the bottom of the page. Of course, the ocean is huge, but using the ocean to generate thermo-electric energy will result in creating a situation where the depths of the ocean are warmer, creating an unknown thermic pollution factor, which will alter weather patterns as well as kill off fish. Just a thought.

<-- begin analysis -->
Any sufficiently advanced society gets to this point of being screwed. We do use an enormous amount of power in the US. At the rate of consumption of the civilised world, which is where this experiment would have to be conducted because the third world can't even feed itself, it is physically impossible to use land both for living and production of solar energy.
Essentially, the sun averages 1kW/M^2 worldwide. Much of this is equatorial, because the change of the angle of incidence results in a greater area being in between the same two rays from the sun. In other words, if one takes two rays say 1 degree apart, these rays have a certain quanta of radiative energy, and that quanta will strike a smaller area if it goes to the equator than towards the poles.
I haven't been able to find the exact numbers, but it seems that a good estimate is around 300W/M^2 in daylight.
The area of the US is 9.63x10^12 M^2. That comes out to a six-hour average max (twilight and dawn are low-energy times) of 6x300x9.63x10^12 WH, or 1.73x10^16 WH.
Now, the energy usage of the US totals 7.24x10^16 BTUs. This includes everything; transportation, industry, and living energy. Source: http://www.eia.doe.gov/emeu/aer/eh1999/eh1999.html

Now, convert that to watt-hours and you have 2.12x10^16 watt-hours. In the US, anyway, there simply isn't enough light incident to the ground to supply power.
Of course, we could float solar panels in the oceans, in space, etc., but all of these are frought with engineering and environmental difficulties.
Actually, the situation is much worse, because the solar energy system described here is electric, and it is only around 10% efficient at *converting* power, so we have 1.73x10^15 WH to play with initially, which we will store and retrieve at 60% efficiency (miraculously high), transmit down lines with 50% losses, and result in terminus usage in the 60% efficiency area, resulting in just 3.12x10^14 WH.
Of course, our average efficiency on fossil fuel usage is around 20%, so we can cut our needs to: 4.24x10^15 WH, which is only 1,359% more than we have.
This isn't even dealing with the horrendous cost and engineering problems with solar power and electrical means of transportation that require transmitted power.
<-- end analysis -->

I'm not doing this again; last time no one believed it.
[ Parent ]
handwaving (none / 0) (#36)
by physicsgod on Sat Mar 31, 2001 at 05:44:36 PM EST

Why do you dismiss Solar Power Sattelites with a curt "engineering and enviromental difficulties"?

AFAIK the only engineering problem is getting that much mass that far into space to be cost effective. In other words we know how to do it, it's just that nobody wants to pony up the dough.

And as far as enviromental effects, the only effect I can think of is the shading effect of the actual collectors, and if that's not negligible they can be engineered around. (placing the collector in solar orbit with distribution sats in geosych"

--- "Those not wearing body armor are hereby advised to keep their arguments on-topic" Schlock Mercenary
[ Parent ]
The cost would be enormous (none / 0) (#47)
by weirdling on Mon Apr 02, 2001 at 12:50:38 PM EST

The idea of solar collector sats is a possibility; best to put them in Lagrange points; that way they do not interfere with the weather patterns on earth. However, power transmission is frightfully difficult. Best idea so far has enormous microwave power beams which are hideously inefficient and have the tendency to fry birds &c. in the atmosphere. If one transmits enough power to make it worthwhile into a small enough beam to make it practical, one runs a terrible chance of burning up anything that gets near the beam, as the air in the beam itself will be very hot. This will likely alter weather patterns all by itself. Essentially, you're pointing a multi-gigawatt beam at the earth, which, considering that your average home microwave oven is in the 1.5 killowatt range, is enough to fricasse a bird in seconds.
Other transmission systems are possible; for instance, you could make a sufficiently dense energy storage system, launch it to the sattelite, charge it, and bring it back down, but it would have to bring with it a multiple of the energy required to get it into orbit to be feasible economically.
Lasers et al have essentially the same problems as microwave: tend to fry things too easily for the energy they create.
A wire attatched to the earth and some sattelite could be used as a power-transmission wire once the problem of finding a wire of sufficient strength to withstand the stresses but light enough to not fall under its own weight is solved.
Far easier to put a nuclear plant on earth and engineer for low environmental impact. Waste heat can be dealt with by putting mylar mirrors in space to reduce the light incident to earth, and these mirrors can be moved around and restructured to increase/decrease effectiveness, making a thermostat for earth.

I'm not doing this again; last time no one believed it.
[ Parent ]
On the fence (4.83 / 6) (#4)
by jabber on Fri Mar 30, 2001 at 04:03:13 PM EST

Then, place a junction in the air intake, with one of the paths having a charged plate next to it. The charged air molecules (including the oxygen) will turn down that path, leaving the nitrogen and other uncharged particles to go the other way.
Do you have any idea of the energy needed to make this happen? I don't, but I'd be willing to bet that the additional power would increase the work done by the engine to a point that would eliminate the benefits. TANSTAAFL

Then, there's the waste heat the engine is producing. That, in itself, isn't a problem. The problem is that that is energy you can't use, and therefore you end up burning additional fuel to make up for it.

Heat is a real problem, since it's a natural result of any exothermic reaction.

So is it, or is it not a problem? What's heat got to do, got to do with it? What's heat, but a by-product of combustion? Do you propose to solve the 'wasted heat' problem on the quantum level? How does that scale to a Cummins Diesel engine?

If you have the car's sides deformable, and push the air left or right, you can meet all those requirements and improve handling AND performance, at the same time.
Jell-O cars? What are you driving? An old Volvo or an 83 Dodge Aries? Read this and note the aerodynamic drag coefficient value in the table on page 1.

Gearing? IIRC, the Subaru XT used a belt-type transmission for continually variable gearing, much like a snowmobile (yes, there is prior art here, don't file the patent just yet). In fact, yes, it did. I remember because I was once stranded for 5 hours on the side of the road with a friend, when his belt broke at a remarkably bad time of day, err, night.

I'm all for the continual improvement of automotive technology, but you're stating the obvious here. There are design engineers, some with decades of experience under their belt, who do this for a living. I really don't think that a grass-roots call to arms is going to accomplish anything at all.

[TINK5C] |"Is K5 my kapusta intellectual teddy bear?"| "Yes"

Variable gear-ratio drive trains (none / 0) (#40)
by Miniluv on Sun Apr 01, 2001 at 04:47:13 AM EST

Honda also did it, with the Civic. They've put it in production for several single year runs, and are continuing to refine the process.

The major advantage is, of course, the increased gas mileage. However it is not a universally applicable solution because internal combustion engines are used for a variety of purposes. Horsepower output versus torque output as an example. Diesel engines create more torque per horsepower than unleaded engines, which is why large load carrying vehicles, i.e. trucks of various natures, tend to use diesel engines.

The variable ratio drive train reduces torque dramatically, for reasons I cannot quite remember. I do know that it has to do with the redistribution of torque from a bell curve to a flat linear distribution. This redistribution is highly undesirable for certain applications.

"Its like someone opened my mouth and stuck a fistful of herbs in it." - Tamio Kageyama, Iron Chef 'Battle Eggplant'
[ Parent ]

I can think of a reason it would be undesirable... (4.00 / 1) (#54)
by nstenz on Tue Apr 03, 2001 at 12:42:46 AM EST

The variable ratio drive train reduces torque dramatically, for reasons I cannot quite remember. I do know that it has to do with the redistribution of torque from a bell curve to a flat linear distribution. This redistribution is highly undesirable for certain applications.

We have a go-kart around here somewhere, and our neighbors up the road have one as well. Ours is a bigger off-road type thing with an 8 HP engine and a torque converter. Its acceleration seems to be fairly linear.

However, our neighbors' go-kart has a 5 HP engine and a clutch. Its slow to take off because the clutch has to catch- I never liked cluthes on go-karts for that reason. However, as it accelerates, it starts to go like a bat out of hell...

It IS like the difference between a diesel truck and a sports car. I'm guessing the CVTs wouldn't wind out as fast? Engineers try to gear cars so the gearing will be lowest when the engine is at a lower RPM, near the fattest part of the torque curve (for a 'good' engine, IMHO). As the car speeds up, the engine produces less torque. Where do you set the 'gears'? The most efficient setting is certainly not the fastest... It can't be; just like perfectly efficient compression on gas is 14.7, but a normal passenger car will average ~8-12, depending on how much air is being shoved into the cylinders (of course, that's because more effiencent combustion than that would melt the pistons, but nevermind).

I'm done babbling now.



[ Parent ]
Re: On the fence (none / 0) (#72)
by BigNachos on Fri Apr 06, 2001 at 03:36:48 PM EST

Ah, it's nice to see that someone else also realizes that this article is a bunch of bullshit...

Automobiles have been refining the same basic technology (internal combustion engines) for over a hundred years. By now, they're pretty damn good.

If you want to significantly change the emissions or efficiency of an auto, you need to drastically change the design. Get rid of the couple thousand pounds of metal and come up with a completely new way to produce mechanical energy. Then you'll be getting somewhere...

[ Parent ]
continuous gearing (4.00 / 3) (#9)
by Michael Leuchtenburg on Fri Mar 30, 2001 at 04:18:09 PM EST

There are actually several continuous gearing systems in existance today, but none of them are efficient enough yet to make any gain over traditionally geared engines.

[ #k5: dyfrgi ]
[ TINK5C ]
And what about IT? (1.25 / 4) (#10)
by fuzzrock on Fri Mar 30, 2001 at 04:22:08 PM EST

As I recall, the consensus around IT is that IT is going to be some kind of transport device...

But this brings up a more serious question, alluded to in the poll and in some earlier questions - why restrict ourselves to refining relatively conventional cars? IT is rumored to be a transport device utterly unlike cars, why can't we think of some too? Bikes with electric motors! Scooters that keep you warm! Something?

The released it (none / 0) (#48)
by retinaburn on Mon Apr 02, 2001 at 01:13:23 PM EST

Its a hydrogen powered scooter apparently. They have a few different configuration ideas on how it will evenually look.

I think that we are a young species that often fucks with things we don't know how to unfuck. -- Tycho


[ Parent ]
You are not an engineer are you? (4.60 / 5) (#12)
by MrAcheson on Fri Mar 30, 2001 at 04:29:05 PM EST

Some of your stuff has been done before. Subaru used to have a transmission called the ECVT, or Electronic Continuously Variable Transmission. They put it on the Justy and some of their other smaller cars. I'm not sure if they still offer it or not. IIRC it worked pretty well.

As for your aerodynamics, you have never taken fluid mechanics have you? Do realize that turbulence actually reduces drag? You actually want to trip the turbulent boundary layer in order to reduce the size of the cars wake by prolonging the distance until boundary layer separation. This reduces the cavitation the car creates which is a major source of drag. This reduces the cars effective drag coefficient. Also grooved surfaces do not "break up turbulence" they create it. You cannot "break up turbulence", turbulence is by its very nature chaotic and "broken up" in ever smaller length scales.

In general you want laminar flow for pipe fluid flow because requires the least amount of pressure head for the flow rate. However with exterior flow you actually want a little turbulence for the reason sighted above because of boundary layer effects you don't have to worry about in pipes.

Also, in general, non symmetric bodies produce both drag and lift. In the case of a car the "lift" is actually a downward force used to improve handling and stability. It holds the car to the road. This is a good thing as it improves energy transmission from the car to the road.

In short, keep in mind you really can't get something for nothing. You are going to produce waste heat in every engine because of Entropy. Try to minimize it but it will always be there. You want a solid safety cage around a cars occupants or they will not survive a crash. Flexibile cars are not necessarily good.


These opinions do not represent those of the US Army, DoD, or US Government.


Ugghh. (none / 0) (#13)
by MrAcheson on Fri Mar 30, 2001 at 04:33:30 PM EST

Ewww. It should be cited not "sighted." God I made a lot of writing mistakes. Me engineer no write good. :)


These opinions do not represent those of the US Army, DoD, or US Government.


[ Parent ]
Tripping the boundry layer.. (4.00 / 1) (#62)
by Zukov on Fri Apr 06, 2001 at 09:33:10 AM EST

Is what lets otters and seals swim so fast, IIRC. The hair on their bodies trips the boundry layer to be turbulent, greatly reducing drag.

There is a classic strobe picture of two bowling balls being dropped in to a giant fish tank. One ball is smooth, the other has sand glued to the front. The bowling ball with sand glued to it's front has a smaller wake, thus a lower drag.

¿ëë±È¶ ±Hæñ ¥ØÜ (§^Ð

Yes, I have just bumbled upon Gnome Character Map. Please ! me.
[ Parent ]

Re: Tripping the boundry layer (4.00 / 1) (#73)
by BigNachos on Fri Apr 06, 2001 at 03:45:25 PM EST

This is also the same reason golf balls are dimpled...

[ Parent ]
Significantly laminar flow ground vehicles (none / 0) (#65)
by kod on Fri Apr 06, 2001 at 11:55:55 AM EST

Significantly laminar flow ground vehicles are possible and provide very desirable benefits. Check out Matt Weaver.

This level of boundary layer control might not be possible with a car, but who said cars were desirable?

[ Parent ]

Bicycles (none / 0) (#71)
by MrAcheson on Fri Apr 06, 2001 at 03:18:43 PM EST

Laminar flow is better if boundary layer separation is not a problem. I believe the overall drag it causes is lower but don't quote me on it because I haven't done the math. So basically if you can have a nice smooth shaped body with no place for separation then laminar flow is better (the typical symmetric air foil for instance). However a car isn't shaped like this so turbulent flow is probably the better choice.


These opinions do not represent those of the US Army, DoD, or US Government.


[ Parent ]
Re: Bicycles (none / 0) (#74)
by BigNachos on Fri Apr 06, 2001 at 03:54:27 PM EST

Laminar flow is always better. The advantage to turbulent flow in some cases is that it can allow the flow to re-attach to the surface more easily, and hence become laminar again. It's difficult to explain without diagrams. Check your fluids textbook.

[ Parent ]
"Always" and "Except" (5.00 / 1) (#78)
by MrAcheson on Sun Apr 08, 2001 at 10:22:57 PM EST

I checked my fluids textbook. Laminar flow is better when you don't have to worry about boundary layer separation because of the low reynolds number or the shape of the body in question. Turbulent flow is, in general, better if you do because it prolongs boundary layer separation and reduces drag caused by cavitation, etc. Therefore laminar is not "always better". Never say "always" in engineering or science as it often results in mistaken generalization of complex ideas. There is almost always an exception.


These opinions do not represent those of the US Army, DoD, or US Government.


[ Parent ]
I have one thing to say... (2.50 / 4) (#14)
by slambo on Fri Mar 30, 2001 at 04:36:31 PM EST

One way ... is to simply have a charged mesh at the front of your air intake.
Just what we need. Another filter to replace.

However, of all the proposals, this is by far the simplest to implement and can be (somewhat) easily retrofitted to existing vehicles, especially if it's incorporated into the existing air filters.
--
Sean Lamb
"A day without laughter is a day wasted." -- Groucho Marx

braking is the biggest problem (4.40 / 5) (#16)
by SEAL on Fri Mar 30, 2001 at 05:20:33 PM EST

I've mentioned this in other threads, but braking is a huge waste of energy. Brakes reduce the vehicle's kinetic energy by using friction, and this energy is dissapated as heat.

That means that you can never exceed 50% energy efficiency in a car using this type of braking.

Regenerative braking is the concept of moving that kinetic energy back into a storage system for reuse. AFS-Trinity is working on flywheel systems which can do exactly this type of job. They can charge quickly, and don't have problems with fade like chemical batteries. They also weigh a lot less.

If hybrid cars like this become the norm, you will see a large increase in gas mileage, and the corresponding reduction in pollution.

Best regards,

SEAL

It's only after we've lost everything that we're free to do anything.

You mean shipstones (none / 0) (#41)
by Miniluv on Sun Apr 01, 2001 at 05:00:19 AM EST

Whee, somebody really is implementing my absolute favorite bullshit Heinlein technology.

Being the particularly anal retentive reader that I am, I'll recall the portion of Moon Is A Harsh Mistress when he broached this idea. The problem was long distance travel in a vacuum to reach one lunar colony from another. The solution was capsules travelling in a ballistic arc just under the surface of the planet.

The basic idea was that some sort of device stored power for the intial launch and acceleration to ballistic speed. This energy is transformed from chemical (potential) to kinetic in the form of a ballistic capsule. At the other end you transform that kinetic energy into something when you slow down, and gee, why not transform it back into potential energy in some chemical form? Obviously there were no exact details, this is fiction with a political twist not Arthur C Clarke, but this sounds like the exact concept.

I'm sure Heinlein ripped it off from somewhere, but it's still really cool that people are bothering to follow up on the idea.

"Its like someone opened my mouth and stuck a fistful of herbs in it." - Tamio Kageyama, Iron Chef 'Battle Eggplant'
[ Parent ]

Sub-surface travel and regenerative braking (4.00 / 1) (#42)
by whatnotever on Sun Apr 01, 2001 at 09:51:38 PM EST

Wait a minute. I seem to recall something similar that makes a little more sense. At least I think this is somewhat different.

If you simply have a straight tunnel from point A to point B, then gravity will do all of your work for you, as the first half will be completely "downhill" and the second half just the equivalent "uphill." You only have to provide energy equal to that lost to friction. A push to begin with will help you get to your destination faster. Technically, it doesn't have to be a straight line, it could be any path that lies entirely beneath the starting altitude... I'm not sure what you mean by "ballistic arc" in this case, because any old arc would do.

In any case, regenerative braking is in use in "real" cars (Honda Insight and Toyota Prius) right now.

[ Parent ]
Ballistic arc (none / 0) (#43)
by Miniluv on Sun Apr 01, 2001 at 10:57:35 PM EST

My understanding of the concept, which he used in more than just Harsh Mistress actually, was that you could travel the distance much quick if you computed an arc where gravity would accelerate you to terminal velocity early in the descent and you could travel at that speed for almost half the distance.

The energy expenditure, which was regenerated in the braking process, was used for the acceleration against gravity in the first stage.

"Its like someone opened my mouth and stuck a fistful of herbs in it." - Tamio Kageyama, Iron Chef 'Battle Eggplant'
[ Parent ]

Ballistic arc (none / 0) (#64)
by bloy on Fri Apr 06, 2001 at 11:37:14 AM EST

I always understood that bit of MiaHM to mean that the capsules were accelerated to oribtal velocity for a radius just under the surface of the moon.

Shipstones, BTW, are from Friday.

(Nope. no anal-retentive readers here)

[ Parent ]

Flywheels (none / 0) (#67)
by ttfkam on Fri Apr 06, 2001 at 12:41:08 PM EST

My father worked on a flywheel project at his job years ago. When at speed, it had a slower speed and when you slowed down, the energy of braking was applied to the flywheel, speeding it up. Then when you started going, the energy from the flywheel was used to get the car moving again. It performed wonderfully! Well... Except when you wanted to turn a corner.

In vehicles with flywheels, the flywheel acts as a large gyroscope. Now think of the size of the gyroscopes we all played with as children -- using them as tops. When you picked one up, keeping it steady was easy. By try to lean it one side or change it's direction...

But who knows. Maybe it'll find application in transcontinental vehicles that move great distances in a straight line.

If I'm made in God's image then God needs to lay off the corn chips and onion dip. Get some exercise, God! - Tatarigami
[ Parent ]
Re: Flywheels (none / 0) (#79)
by SEAL on Wed Apr 11, 2001 at 04:10:31 PM EST

Well, remember that precession occurs with any rotational torque. A single prop plane will show this when its tail lifts off the ground. It must counter with the rudder a bit.

As far as a car is concerned, what happens is the car motion becomes a wear & tear issue for the flywheel bearings as they counter this. Mechanical bearing systems have serious problems here, as well as heat, which translates into lost efficiency.

The newer magnetic bearing solutions seem to be the route most teams are going. AFS has already produced a prototype car a couple years ago. The main thing holding these back right now is safety. You need your flywheel and containment to be predictable in the event of a failure. Otherwise you could expose people to a variety of Bad Things(tm). Shock, shrapnel, launching the car itself up in the air or rolling it, etc.

- SEAL

It's only after we've lost everything that we're free to do anything.
[ Parent ]
Physics (4.33 / 3) (#18)
by typo on Fri Mar 30, 2001 at 05:31:25 PM EST

Ke is actualy 1/2 m v^2

As for the peak performance of the engine you miss the main point. Internal combustion engines have such limitations but electric ones don't.

That's why some mixed electric/combustion cars don't connect the combustion engine to the wheels but instead put it running at peak performance producing electricity to feed the electric engine.

If we're into cool ideas of how to tackle the clean energy problem why not go for the true inovative solutions like cold fusion, solar powering, fuel cells....etc

All of which will probably mean designing electric cars instead of your half assed "deform the car for curving aproach" which (if I got it right) will not work since without enough down force to stick the car to the road you're only goine to make it spin around itself instead of actualy performing the curve.

Social problems require social solutions (4.60 / 10) (#19)
by Estanislao Martínez on Fri Mar 30, 2001 at 05:40:20 PM EST

Whatever the technical merits to your ideas may be, technical solutions to social problems, in the general case, suck horribly. If we're just going to talk about transporting people while producing less pollution, well, the lower the vehicle to person ratio, the more pollution generated (keeping vehicle type constant). So the first obvious solution is, duh, public transport.

Your whole attitude about the problem of pollution, that of looking for a technical solution, just fails to address the root causes of the problem. Pollution has much more to do with urban planning and socialization than with particular transportation technologies. After all, how did workers end up living in suburban areas 20-60 miles away from their workplaces, each one with her own car (which transports only her; her spouse has a separate car), driving 2+ hours each day on roads horribly crowded with people doing exactly the same thing?

Have you ever noticed the direction which cars have evolved over the course of time? Roomier interiors, air conditioning, radio, CD changers, reclinable seats, etc. "Modern" industrial civilizations have take the car, and each year, try to make it more and more like a house, because every yeard we end up spending more and more time inside our cars, as the economy "grows" and suburbia sprawls further, the roads get more and more crowded, and we spend more and more time inside our cars. The technology reflects the society that created it. If people only had to drive infrequently 15 min. spans in uncrowded roads, accompanied with others in the car, do you think cars would be designed the same way?

Is this a naturally given state of affairs? Hell no. This arose because of the actions of people, and can be reversed by the same means.

It is relatively easy to look at a technological artifact like a car in input/output terms, and think of ways to optimize the I/O relations so as to make a small reduction in some perceived problem. It is much tougher to look at the artifact in its social context, and redefine the social context so as to make the old problem simply disappear

--em

Not necessarily (none / 0) (#20)
by weirdling on Fri Mar 30, 2001 at 05:50:58 PM EST

It does not follow that reducing the number of occupants per vehicle must needs increase inefficiency. Particularly in the case of your average bus deadheading out to get someone, driving back, stopping at every streetcorner to pick up someone or drop someone off, normally averagine perhaps ten or twelve passengers for the total trip. When you add it all up, the personal car is not so bad of an idea. Even better is the motorcycle.

I'm not doing this again; last time no one believed it.
[ Parent ]
You, sir, are obviously not paying attention... (1.00 / 2) (#24)
by trhurler on Fri Mar 30, 2001 at 06:15:19 PM EST

to the real world. You will NEVER get US citizens out of their cars. Why? Because they're convenient and they're a great ego boost, and also because driving across town is a whole lot faster than being on a bus or a train that stops every two seconds.

Given this FACT of reality, which you cannot change no matter how hard you dream about it, what can be done? Well, first off, fuel cell powered cars are looming on the horizon, and they produce water vapor as emissions. They're cleaner than the human body itself by a large margin. Second, we can recognize that cars are not the major polluter in the US; coal plants are. Worry about the big dogs first. And third, we can quit letting daydreamers like you try to set policy, because that'll never work and it is a huge waste of money.

--
'God dammit, your posts make me hard.' --LilDebbie

[ Parent ]
Your words betray you. (none / 0) (#26)
by Estanislao Martínez on Fri Mar 30, 2001 at 07:00:43 PM EST

You will NEVER get US citizens out of their cars. Why? Because they're convenient [...]

The convenience comes about not because of facts of nature, but because of the way US society strctures temporal, spatial and economic relations.

[...] and they're a great ego boost,

Sure, *you* had to point that out, didn't you?

Anyway, whether cars are an ego boost or not has to do with socialization.

[...] and also because driving across town is a whole lot faster than being on a bus or a train that stops every two seconds.

The importance of "speed" is cultural, too. Try telling this argument to a believing Amish. "With a car, you can travel many many miles very quickly!" "But why would I want to?"

Given this FACT of reality, which you cannot change no matter how hard you dream about it, what can be done?

I was unaware of the fact that I was proposing "dreaming" as an effective course of action. Thank you very much for revealing to me what I have said.

--em
[ Parent ]

Freedom (none / 0) (#33)
by paulT on Sat Mar 31, 2001 at 10:00:55 AM EST

You seem to be thinking US citizens are somehow hard wired with these behaviours and lack the individual free will to make decisions about their behaviour. The suggestion that somehow the people of the US are going to remain as they are for the rest of eternity is just weird and makes me wonder what the point of "freedoms" in the constitution is.

On a practical note, the decision of people to rely on the car has a lot to do with where people are and where people are going. I drive when it is impractical to go by another means. I live in a community where most of the necessities of life (food, clothing, my bank, a drugstore, used bookstores, new bookstores, record stores, a bakery, and live music) are all within a 10 minute walk. My work is a 15 minute bike ride away. Suburban neighbourhoods are built with an assumption you will be driving and all those things I would normally walk to are too far away to walk conveniently or require a trip on a freeway.

The point is: people use cars because they need to. They need to because of the way our cities are built. If we build our cities more intelligently people will drive less. Behaviour can be changed, we do have free will, and we can make decisions. What's the point of living in a "free" country otherwise?

--
Typing a word a in ALL CAPS does not make it true.



--
"Outside of a dog, a book is probably man's best friend; inside of a dog, it's too dark to read." - Groucho Marx
[ Parent ]
Well combine cars and trains then. Like this... (3.00 / 1) (#60)
by NKJensen on Wed Apr 04, 2001 at 06:57:02 AM EST

This project aims at combining cars and trains or at least to take the best of two worlds.
--
From Denmark. I like it, I live there. France is another great place.
[ Parent ]
shouldn't we work from both ends? (4.00 / 1) (#28)
by SEAL on Fri Mar 30, 2001 at 08:25:27 PM EST

I don't deny that there are social problems to be solved, but that is no reason to shy away from technology. The research and development work that is done to increase the efficiency of cars can also be applied towards public transportation.

Say we completely switched over to mass-transit systems, and no one owned a car. The mass-transit system itself would still benefit from the technology.

For example, much of our knowledge of aerodynamics has been applied towards high speed commuter trains. Another example would be military research on nuclear and conventional steam power plants which has increased efficiency and been retroactively applied to commercial plants.

- SEAL

It's only after we've lost everything that we're free to do anything.
[ Parent ]
What you really want to minimize is... (none / 0) (#59)
by ucblockhead on Tue Apr 03, 2001 at 04:58:44 PM EST

Not the vehicle/person ratio but the vehicle mile travelled/person. Getting people into buses, sharing rides and the like is only one possible way. Also important is designing cities so that people don't have as far to go. Changing a person's commute from 30 miles to 10 miles cuts pollution more than getting two people to carpool 30 miles. And it tends to be more attractive to the individual.

Really, the solution lies not in technical fixes (as you say), but in my mind, it doesn't lie in public transit schemes either. Public transit tends to have problems because of the lack of freedom involved and the inconvenience that must be put up with on the part of the users.

This is usually ignored by those pushing public transit, but its really an important factor. I personally ride San Francisco's Bay Area Rapid Transit system every day, and it's great, but using it entails sacrifices. Less freedom of movement at work. Being at the mercy of schedules.

No, where the solution lies is in the suburban sprawl you mention. Get rid of that. That's the root of the problem. This is especially true because public transit systems have an extremely hard time dealing with the distances between things in suburban areas.


-----------------------
This is k5. We're all tools - duxup
[ Parent ]

Hmm... (4.63 / 11) (#23)
by trhurler on Fri Mar 30, 2001 at 06:09:43 PM EST

This is an area of interest to me. Unfortunately, there are some serious misconceptions going around among physics types about the actual way a car works:)

First of all, the "classical" aerodynamics you talk about, ie generating downforce, are generally quite a good thing in the cars that have them. This increases the force of friction, but it also increases the surface area of the tires that is held against the road at any given time, reducing the odds of the tires simply slipping across the surface if part of one hits a rock or something. Without that, you're going to lose bigtime, although I grant that most cars don't have or need much downforce just for puttering around town.

Secondly, the "deformable sides" thing you're talking about is all well and good, except that it is going to be prohibitively expensive to manufacture and your car is going to have to look like a slightly amorphous vertical wedge to make it work, which precludes putting the engine or any useful cargo in the front. In addition, at normal commuter speeds, you aren't going to get enough assist from the wind to matter much; the nice part about that is, you also won't get enough loss to wind resistance to matter much, although obviously it will be there. Better designs today already reduce aerodynamic drag to very low levels anyway, and they're cheap to produce.

Third, continuously variable transmissions do not achieve what you're hoping for, because of two factors. The first is that you can't hold the car at a constant rpm and get much gain; the transmission needed to withstand the strain of accelerating the car directly in this fashion is too heavy and too mechanically lossy to really help you much. The second is that when you go to design one that always keeps the car in the power band and shifts along a continuous transmission, which is better, you run into all the difficulties of automatic transmissions: the current location in the power band simply is not the only measure of when to shift for optimal fuel economy. Also needed are such things as, are you going to slow down soon, are you going to accelerate, are you going up or down an incline, and so on. Drivers know these things; machines do not.

Fourth, the whole point of a muffler is to create turbulence to break up soundwaves; you do not want smooth airflow.

Fifth, your nitrogen reduction system has two major problems. First of all, oxygen enrichment won't help the engine if there isn't enough oxygen; you're going to need a forced induction system to keep enough oxygen flowing through your more complicated intake, and that's going to sap power off the engine, reducing fuel economy. This is particularly true because the charged particle path must be the path of greatest resistance to keep the nitrogen from just accidentally "wandering" in. The second problem is that the grid itself is going to reduce airflow, meaning you're going to need either a bigger intake or a more robust forced induction system; the former screws up your previously mentioned vertical wedge shape, and the latter screws up your fuel economy.

By the way, the deformable sides and so on isn't as big a win as you'd hope; a large part of the waste heat you're producing is purely a product of the internal combustion engine's design, and cannot be mitigated by reducing the load on the driveshaft, which is what you're trying to do. Blowing up hydrocarbons and then using the gases produced to move a piston while ignoring the heat is wasteful, but that's how the design works, and you can't trade heat for gas volume in the way you're trying.

All that said, I do kind of like the idea of deformable bodies... but it wouldn't be cheap, and it'd probably be used to enhance downforce on race cars:)

--
'God dammit, your posts make me hard.' --LilDebbie

A few things to clear up (4.20 / 5) (#29)
by DoubleEdd on Fri Mar 30, 2001 at 09:16:04 PM EST

Aside from what has already been posted it's worth pointing out the following:

One way (and it's not necessarily the best or the most efficient for this purpose) is to simply have a charged mesh at the front of your air intake. The electrons around oxygen are much easier to displace than those around nitrogen, leaving the oxygen pairs charged and the nitrogen pairs uncharged.
Then, place a junction in the air intake, with one of the paths having a charged plate next to it. The charged air molecules (including the oxygen) will turn down that path, leaving the nitrogen and other uncharged particles to go the other way.

Its not at all obvious that this is practical. It isn't clear that you supply a sufficient charge to enough molecules of oxygen, and it isn't clear that these ions floating around in the airstream are going to experience a sufficient force to get them to travel many mean free paths (possibly losing their charge on the way) and taking an entirely different route. You need a lot of air to supply an engine, and I doubt this'd make an appreciable difference. You are far better off carrying purified oxygen with you, then you get screwed by the ridiculous level of danger that presents. I could be wrong on all that though - I'm not an expert on that, I'm pretty much just guessing based on the fact that I've never heard of anyone seperating gases that way.

In this next bit, I'm not sure what you are getting at, but I'll see what can be done:

Then, there's the waste heat the engine is producing. That, in itself, isn't a problem. The problem is that that is energy you can't use, and therefore you end up burning additional fuel to make up for it.
However, both Classical Physics and Quantum Physics come to our rescue. (Phew!) In classical physics, you must always satisfy the conservation of momentum AND the conservation of energy, where momentum (M) and kinetic energy (ke) are defined as: M = m.v, ke = m.v^2 (where m = mass and v = velocity).
Well, as someone already said, you missed the 0.5 in your KE, but that doesn't really matter. Thats just being pedantic
Because momentum is a function of velocity, whereas kinetic energy is a function of velocity squared, not all values are going to work. Some situations are simply impossible. All you have to do is make the engine a system where the "surplus" components needed to satisfy both equations are nearly zero. The better you can do that, the less waste heat you will produce.

In my experience this is a pretty inconvenient way to think about how to make an engine more efficient. See what I have to say below.

Now, we get into the quantum physics. These systems are not continuous. They operate in fixed-size steps, called quanta (greek for 'enough'). The energies of any given region will be quantized and can never have any values outside of that. To ensure that we get the results we want, rather than some alternative solution to the classical equations, we must ensure that the solution we want satisfies the conditions imposed by quantum mechanics, and that ALL alternative solutions to the classical equations would violate these conditions.

Quanta is greek for 'packets'. It is true that the energy of any given region is quantized, but for a 1 litre engine cylinder the spacing between energy levels is TINY. And when I say TINY I mean mind-bogglingly tiny. This is why Thermodynamics, that wonder of 19th Century Physics that came out of the Industrial Revolution is blooming marvellous at handling engine efficiencies despite ignoring Quantum Mechanics. You really don't need to dirty your hands with this - you can get away with some chemistry (which admittedly is more quantum mechanical) and a healthy dose of thermodynamics. Anyway, even taking your approach it isn't clear how to proceed on to making a more efficient engine. I think the internal combustion engine as it stands is pretty close to optimal efficiency, and with catalytic converters has about as low emissions as you are likely to get. You really need to start looking into new types of engines if you want to cut down on pollution.

Don't waste your time on exhaust turbulence. By then the energy has already effectively left the engine.

Streamlining - modern cars are designed to be streamlined. They aren't bricks. Take a look at one and you'll see the curves.

Basically we don't want to be squeezing out the last percent or two of efficiency out of petrol engines. We don't want to be cutting the pollution pouring out of our petrol exhausts by those last fractions. We want to be thinking of something that doesn't run on petrol at all (and I'm not talking herbal tea, like some nutty guy a few years back ;-) )

Quanta is all Greek to You! (4.33 / 3) (#34)
by The Cunctator on Sat Mar 31, 2001 at 11:19:48 AM EST

quanta (greek for 'enough')
No!
Quanta is greek for 'packets'.
No! Quantum, quanta is Latin. Quanta is the nominative plural of second-declension neuter word quantum. The etymology: [L., neut. of quantus how much, how great.]

It's been used in a legal sense to mean "a sum, an amount" since the 17th century.

Einstein was the first to use the word in its modern physical sense: energiequanta, in his famous 1905 photoelectric effect paper.

[ Parent ]

Funny.... (none / 0) (#39)
by DoubleEdd on Sat Mar 31, 2001 at 08:46:13 PM EST

Fancy that. I go and double check what I thought (ie that it was a referal to an amount or portion (which is what I meant by packet, rather than the brown paper thing you put food in!) ) and I find it in a Latin dictionary and THEN go and post it as a Greek word. Sometimes I'm really not with it....

[ Parent ]
Transportation Pollution (3.33 / 3) (#30)
by _Quinn on Fri Mar 30, 2001 at 09:23:37 PM EST

   More efficient cars will help, as will progressive tightening of emission controls (some states still don't have regular emissions testing!), but as others have noted, we don't need a better solution, we need a different problem.

   Industrial and commercial transport would benefit from a better (faster, larger) rail network; my understanding is that most of it's carried by trucks now. This is probably just a matter of spending the (very large) amounts of money to get it done.

   Personal transport, however, is more polluting (IIRC), and less susceptible to economies of scale. (That is, I'd think enough industrial and commercial transport is over long enough distances that it could be economical to spend a great deal of money on a very good long-range transportation system.) The destinations and trip lengths and transportation needs vary too widely for a (known to me) system other than the personal automobile. However, I think if you look at where people go, it's typically home, work, or some places close to either end-point or conveniently along the way, or shopping.

   We can safely ignore activities `close to home;' the only way to cut down on car use there is to encourage (tax breaks?) developments of say, grocery stores, closer to residential areas, and the car is already there. (I assume you can't convince most people to become more crowded.) However, what about things done close to work? What's the factor requiring people to use cars from work to go there? (Supposing, for the nonce, that people wouldn't otherwise mind taking mass transit; with enough money (subsidies for cheap passes, faster and larger networks), we can assume we make this attractive.) Is it just hauling the stuff you buy all the way home? (Should we be investigating (personal) hauler-bots?)

   Going to places like the mall is an interesting opportunity for the mass-transit equivalent of the local-area network. I'd think people would want (a) to get on/off near their home and (b) go directly to the mall, without wasting time picking anyone else up. (Emphasis here on making it to the mall as fast or faster (cheap or cheaper) than a car. Same condition -- hauling things around -- may apply, so the local-area transporter must address this as well.) The difference here is scale; a system going to downtown NY has a potential ridership in the millions; a system centered around the BigMallOfTheSuburbs has a potential ridership of thousands. (Another note: when I say network, I mean it. None of this random irritation about changing how you pay for public transit because you switch types or systems. As an example, the bus system and the subway system should both have those card-reader things installed at every entry, and not require you do go through them until you exit the system.)

   Quite frankly, I have no idea; the best thing I've been able to come up with is same-day delivery for /everything/, so you don't have to haul stuff around... and that doesn't address all the issues.

-_Quinn
Reality Maintenance Group, Silver City Construction Co., Ltd.
Bzzt! Sorry, wrong answer (3.16 / 6) (#35)
by khallow on Sat Mar 31, 2001 at 04:54:52 PM EST

The domestic car is probably one of the easiest offenders to tackle, so I'm going to start there.

Unfortunately, this isn't the case. Historically, distributed sources like automobiles, wood fires, gas-powered leaf blowers, etc. have been some of the hardest pollution sources to regulate. It's the different between regulating a few hundred "point sources" and a few million distributed ones. That's one of the reasons that electric cars may actually be extremely beneficial. Because they replace the distributed nightmare with a bunch of point source electric plants.

A true pollution-free method of transportation is telecommuting. Think about it. If you don't make the trip, then you don't pollute.


Stating the obvious since 1969.

Take a physics class. (1.80 / 5) (#37)
by physicsgod on Sat Mar 31, 2001 at 05:57:33 PM EST

You are WAY over your head.

Others seem to have a good job discussing the quantum, continuous gearing, and aerodynamics, so I'll take apart the comment that made me stop readig the first time.

Heat. An internal combustion engine is a heat engine, which means the heat you're complaining about is the reason the whole damn thing works in the first place.

Now you could get away from heat engines entirely, but then you're in the realm of fuel cells and the like, and they have their own special problems that can wait until you can tell your Hamiltonian from your Lagrangian.

--- "Those not wearing body armor are hereby advised to keep their arguments on-topic" Schlock Mercenary
I agree (none / 0) (#49)
by georgeha on Mon Apr 02, 2001 at 01:45:03 PM EST

which is why I'm voting this down, I think the submitter needs a better grasp of thermodynamics, physics and aerodynamics before approaching from a technical standpoint.

[ Parent ]
A thought... (2.50 / 4) (#45)
by Signal 11 on Mon Apr 02, 2001 at 12:07:37 PM EST

You may be simply moving the pollution to another area - manufacturing. How much in the way of pollutants are released by manufacturing pollution-free cars? Just a thought...


--
Society needs therapy. It's having
trouble accepting itself.
Vehicle maintanance (3.40 / 5) (#50)
by dyskordus on Mon Apr 02, 2001 at 04:39:20 PM EST

Pollution problems could be reduced if more people would properly maintain their vehicles.

In areas where cars have to go through emissions tests before they are licensed, people generally only have their cars tuned up if they do not pass the test.

IANAM (I Am Not A Mechanic), but I have often worked on friends and family member's cars that would not pass emissions tests. I have often discovered air filters so filthy that they were black, and horribly fouled spark plugs. After replacing these, and possibly a few sensors (oxygen, water temp, etc), these people were amazed with the improved gas milage and power.

None of these things are difficult to do. I cannot understand why, in a society so vehicle dependant as the U.S. does not teach this sort of thing in school or make basic vehicle maintainance skills a requirement for a driver's license.


"Reality is less than television."-Brian Oblivion.

72 m.p.h. under human power (4.50 / 2) (#63)
by kod on Fri Apr 06, 2001 at 11:29:32 AM EST

Speed 101

Human Powered Vehicle Assoc.

Your comment that a brick would only be marginally worse is inaccurate in many cases - quite a few cars actually have Cd > 1.0, meaning it'd be easier to push a brick through the air.

Cars are intentionally 'engineered' to be big, heavy, inefficient (see SUV's), and in many cases, non-streamlined (see racing cars). If you want to see some truly revolutionary vehicle design, check out the guys that are going 1/10 the speed of sound using at best 1 hp.

Hybrid car (none / 0) (#66)
by ttfkam on Fri Apr 06, 2001 at 12:29:57 PM EST

Gas engines are better for higher speeds. Electric motors are better for lower speeds. The idle of a gas engine at lower speeds tends to push economy down (why most are most efficient at 40MPH). Electric motors become less efficient the higher the draw. But they do not idle at low speeds.

A large battery keeps a store of energy for stop-and-go, low speed, and supplemental power. The engine keeps a relatively constant RPM with the battery give and taking slack for minor variations. The engine, when underused, recharges the battery.

Couple this with a Continuously Variable Transmission where you can think of a large, slightly conical drum with a belt that "slips" up and down to arbitrary points for a free range instead of fixed gear points.

Have coasting and braking act in such a way that the electric motor gets driven by the momentum of the car itself. This turns the motor into a generator, thus charging the battery.

Put four doors on it, make it look and act like a normal car, and make it affordable. Hell, I'd buy it. Oh THAT's right, I already did.

2001 Toyota Prius.

I only have one complaint; It doesn't have cruise control. But I still giggle at stop lights when there is no engine running...

If I'm made in God's image then God needs to lay off the corn chips and onion dip. Get some exercise, God! - Tatarigami
Wrong, Wrong, Wrong (4.00 / 1) (#68)
by celtichack on Fri Apr 06, 2001 at 02:18:15 PM EST

Not to burst your bubble but, the single largest source of pollution is farming! Cars don't even add a double digit percentage to worldwide polution (sorry I don't recall the precise number). Secondly, take a physics class or too beyond Physics 101. Then take an aerodynamics class. Then take an engineering class. Lastly make sure you have the right knowledge before posting an open letter to the world. Sorry, but as has been noted, you have made numerous errors on numerous fronts. You do have the right spirit though, and with some knowledge accumulation you may come up with a workable solution to some polution problems.

You want less pollution? (none / 0) (#69)
by cr0sh on Fri Apr 06, 2001 at 02:52:08 PM EST

Then I have one name for you:

Paolo Soleri

Discuss...

Arco's! (5.00 / 1) (#76)
by Tr3534 on Sat Apr 07, 2001 at 11:14:19 PM EST

Wow. Someone actually mentioned the classic idea of the arcology?
I thought that all died out years ago when SimCity 2000 was no longer
an up to date simulation.

Nice to see the project is still continuing. Really, though, arco's will
not be built by going for a full-sized one as a first. Your going to need
to start with small projects, such as an apartment building with shops,
offices, and small scale workshops along with the residental bits. Things
that can't contain themselves first.

Sigmentation Fault: Post Dumped.
[ Parent ]
Which... (5.00 / 1) (#77)
by cr0sh on Sun Apr 08, 2001 at 03:50:09 PM EST

...is essentially what Arcosanti is, at the present moment. A quick perusal of the web site will give you that much overview.

The whole concept really involves living in a large volumetric space, in harmony with the surrounding land and with the people near you. Since in the end it would essentially be a large beehive like apartment-type complex, quite a few social attitudes would have to change - the largest being the concept of land ownership.

At the present point in time, arcologies should be the way we build cities, but social attitudes aren't allowing for it. Even whe people decry loosing the beauty of the environment they are in (look at Arizona's Prop 202 from last year), when it comes to idea that jobs will go away, it is "fsck the environment - sprawl is it!" - rather than thinking, "Gee, if we go vertical, we will still have jobs, be able to house as many people, and still have the environment to play in and admire"...

Until the attitude changes, arcologies will be just another idea. Sadly, the attitude won't change until we have devoured all possible livable land, paved everything over, poisoned the air and water with a ton of polutants from our vehicles (which would be unecessary in an arcology), and are generally misirable. Unfortunately, by that time arcologies will spring up looking more unplanned - a large-scale tenament type structure (think Cabrini Green massively scaled up), but none of the ground will be returned to a native state, instead becoming the "inner-city", in a literal sense.

I come to think of it as a combo of what was portrayed in "5th Element" and "Blade Runner", with a fair amount of leaning toward BR.

Humans are that selfish...

[ Parent ]

this one? (4.00 / 1) (#70)
by Manish on Fri Apr 06, 2001 at 02:55:24 PM EST

Hi jd, are you the same one who posted this at ShouldExist?
Manish.
(Nearly) Pollution-Free Transit | 79 comments (72 topical, 7 editorial, 0 hidden)
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