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Gas/Hybrid, Diesel, Diesel/Hybrid, Fuel Cell - where will it end? 13

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SomptingGuy

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May 25, 2005
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See title. An open question to all. What will we be driving in 10 years time? (I'll have added another 20k to my '87 Volvo, but that's another matter).
 
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I don't quite see the point of a hub motor:
* Much more unsprung mass.
* Electric motor will endure severe accelerations.
* Less space to accomodate brakes.
* 2 electric motors are heavier, more complex and less efficient than one.
* A gearbox is not really an option with a hub motor (an electric motor has an efficiency curve as well).
 
No halfshafts, no diff, no diff losses (15% worst case), better packaging.

But yes, there are disadvantages, not least the financial problem when you kerb a wheel.



Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
 
Hydrogen or air they are just batteries. the process to make hydrogen from electrolysis is 40% eficient, from methane 50%, why not skip it and go straight to electricty.

The air is almost 100% plastic so it gets great "mileage" but it won't ever be here for safety reasons.

Plug cars with nuclear plants will be the answer. Unless you need to go cross country. Then liquid fuels.
 
The enrgy density of air stored at 4500 psi in a reasonably safe cylinder is about the same as a lead acid battery.

So, if you can design a valid aircar, then you could design a valid electric car (except for the recharging problem).

Demonstrably people can't, using lead acids.

There is also an efficiency problem with the aircar.

If you charge it quickly then you'll heat the air in the tank. If you don't cool it down you reduce the range. If you do cool it down then you lose that energy.



Cheers

Greg Locock

SIG:please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
 
I can't quite figure out why Tata Motors are interested in this. All I can think of is that some non-engineering manager is trying to buy in some "green" credentials to an otherwise also-ran car company.

- Steve
 
I can see 5-10 years bringing diesel up another 10% market share in europe and maybe even 20% extra share in US. Then we will also have almost all new SI cars having fuel systems to cope with bio-fuel substitute in the dinofuel. This will pave the way for a greater subsector of the main industry that specialises in bio fuels, from production of fuel to production of engines. The cost is low for the consumer as relatively little needs to be changed and there is no huge marketability value compared to the prius etc.

The problem is the infrastructure will still be the one used by the dinofuel monopolies to supply the extra biofuel, so the price will be set by them. I predict that a smaller company (e.g. not BP or Esso) will see the market advantage of being able to supply higher concentrations of bio-fuels to an already converted market (in engine terms) at a lower price than normal pump fuel whilst beng able to use the 'green' marketing strategy. The trillions of dollars tied up in the remaining oil is enough to pay these people off of course.

Hydrogen will not make it. As suggested it is just an energy store and a poor one at that. Also there has been little mention of the devastation caused when a hydrogen cell ruptures during a collision in real life. The damaged area is in the order of 40x larger than a conventianally fuelled vehicle, i.e. the shop across the street from a car accident will be damaged!

The future is in highly efficient, small biofuel sipping SI(GDI) and CI engines with supercharging and energy recovery systems. These technologies can evolve from their already mature markets rather than being a huge upheaval like hydrogen or electric power would be. This will also keep the oil companies happy until their prices can no longer be tolerated. In the UK the price of a gallon of diesel is already at £5 ($10). I have been using rape oil from the supermarket as 50% of my fuel for almost 10 years now, and know plenty of people who do also. The market is there for anyone who takes the plunge into biofuels for real. Production of biofuel stock is still a risky issue as poorer countries will chop down rainforest to grow it and sell it back to us. There have been advances in other production areas, such as turning waste into fuel using genetically engineered bacteria.



 
I agree the Tata MDI Aircar tie-up is pretty odd. Tata do invest in advanced technologies, they are an interesting company in my opinion.

My guess is that it is a two way street - MDI get production expertise (sorely needed), development expertise (ditto) and vastly improved access to Indian manufacturing. Tata get a toe in the water if the aircar ever becomes a saleable product. If...

Cheers

Greg Locock

SIG:please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
 
Direct injection, due to higher pressures and greater efficiency. Diesel has that already, but gasoline/petrol engines can have it too, eg Mistubishi's GDI and Volkswagen's FSI. There is no reason that I see (other than cost and manufacturers sweating their carburtor engine assets) to go halfway and up the compression ratio to the point where the fuel compression ignites (HCCI) without upping the compression ratio further still and injecting it to stop it burning too soon.


I think we will see some form of energy recovery, a bit like KERS being introduced in formula one, but I don't know what form energy recovery will take on the streets.

My understanding of flywheels is that for a street car, a flywheel would have to be on the engine side of the gearbox, whereas for F1 it's being designed to go wheel-side. I estimate it can be used from about 75 MPH to 225 MPH. Below that you might not need it due to wheel spin from eight or nine hundred horsepower. On the street you'd want to use recycled energy at low speeds, eg in start stop traffic - that's very different.


Supercapacitors and electrc motors?
I don't know enough about it. The energy capacity of the top supercapacitors looks good on paper, but whether they can be made at those power densities at a low cost I don't know; I have my doubts.


If you recover energy with an air tank, can engine and exhaust heat be used to increase pressure and thus provide a form of waste heat recovery in a practical manner, and could something like that lie behind Tata's interest in the air car, rather than Tata thinking of the air tank as the prime mover?


Apart from that I just see incremental improvements:- more gears, electronic control of the gearbox being used instead of manual or mechanical control, aggressive shift logic, more use of economy overdrive ratios, dual clutches and similar, battery charging on braking only, engine off when stopped, more diesels, smaller engines, electric oil devices used as much as required where mechanical oil pumps etc follow engine speed, electronically controlled valves, ...


Basically, I envisage energy recovery and incremental improvements. Electronically controlled valves should allow real compression ratios to vary to avoid knock and oxygen sensors should allow AFRs to vary to adapt to different fuels, so I imagine we'll see cars that car run on a variety of fuels.

Even if there is a switch from one fuel (hydrocarbons) to another (hydrocarbon agrifuel mixtures, more carbohydrate), there would logically be a time of mixted fuel availability and so the logical choice of vehicle would be one that can accept multiple fuels, eg gasoline/petrol and ethanol, but once gasoline/petrol is direct injected at pressure where it will autoignite, the real difference between fuels is eroded, just like electronic control erodes the difference between manual and automatic gearboxes.

=

The Tesla, with its ability to go 200 miles downhill and a its otpional diesel generator to recharge it? Nah, I don't see that as the future. It's a milestone in the history books, marking a change in battery technology, but not much more than that. I do 600 mile journies at times. The solution for that with the Tesla would be to buy the optional diesel recharger and to recharge while driving to reduce stopage time. That would in my opinion make the Tesla a diesel. Yes, you can burn the diesel in a power station, and yes the power station could be coal powered or whatever. That makes the Tesla nevertheless a disel or cola powered car. It could be nuclear. But in my opinion, use the nuclear electricity for houses and take an oil power station out of service and use the oil for cars - it makes more sense than using the oil for homes and electricity for cars.

There will always be some guy living on a hill with a wind turbine or by a river with a waterwheel. I think everything including the Tesla should be developped. I just see those things as niche market rather than mainstream. But as life gets harder with the easy oil disappearing and population increasing, diversification will be more important and there will be more of a market for niche technologies.

The advent of automatic transmissions that will fit small cars will cause a change in American city driving habits. Where small cars were only available as manuals and rejected by the American public in the times of cheap oil, new small car automatics sales will explode in US cities in the years to come when oil starts to become expensive.

In many places a litre of the world's non replaceable oil still costs less than a litre of renewable organic milk. Although I love to quote that one, I think finally fuel here costs more than milk, but it is still an illustrative example.


 
In 10 years time, I believe will will still be driving vehicles fuelled mostly from petroleum. Biofuel use will increase, but will not make up the majority. CTL/BTL/GTL fuels will be blended in varying percentages to normal pump fuel in certain markets. EVs and FCEVs will be a small percentage of the market. A hydrogen infrastructure will still be far from widespread to be practical.

We will continue to rely on the internal combustion engine for a vast majority of vehicles. Hybridization in various degrees will become very commonplace, almost ubiquitous like fuel injection, air bags and ABS have. Plug-ins: see hybrid above. Compression ignition engines will capture a bigger share globally, but multi combustion mode engines (HCCI/CAI/PCCI) will begin to come on-stream. Engines will be substantially downsized from current norms, about 3/4 to 1/2 current displacements, and a large percentage will be force-inducted. V8s will still be around but fewer in marketshare percentage. V10s and V12s will be all but relegated to extreme niches.

In North America, automatic transmissions will feature more gears; 6 will be minimum from 4 today. 8 will become fairly common for more premium cars and we may see 10-speed automatics. Dual-clutch automated manuals will see lots of growth, but CVTs will increase weakly or remain stagnant. We already see 7-speed DC-transmissions, 8 will be quite likely. Manuals will still be around but marketshare-wise declining in percentage.

Vehicles themselves will not get significantly smaller, but there will be a wider spectrum between the largest and smallest on North American streets, with growth on the latter. Unfortunately, I don't see weight trends going down significantly; the trend is still for an increase, but this will flatten out and maybe (hopefully) reverse itself rather slowly.

I believe most of the fuel efficiency measures embraced in terms of largest user base will be in transit vehicles, trucks, and taxis.
 
Let's just say that that 150 mpg figure is more of a publicists delight than a scientifically grounded estimate.

Most Plug in hybrids will be plugged in at night. Most night time electricity is generated by base load generators - coal and nukular.

for details of their oh so technical proof of that figure.

Cheers

Greg Locock

SIG:please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
 
Silicon nanowire batteries currently being developed in laboratories hold the promise for a 10 fold improvement in energy density compared to current lithium batteries. The technology could be the breakthrough in batteries that the electric car & hybrid's need to be practical. Unfortunately, it probably is 10 years from production & may not prove practical in the long run. Of course, the power will still have to come from somewhere.
 
Energy density of hydrocarbon fuels (diesel, petrol, kerosene) is hugely superior to any currently viable battery technology, compressed gas, or hydrogen fuel.

A sensible mass or volume of diesel (ie a tankful) will get you 1000 km in most cars. And it takes 5 minutes to refill for another 1000. 60kg of batteries will get you to the shops and back.

Even with their low combustion efficiency characteristics, HC fuels are here to stay, even if they become even more expensive.

In UK, diesel now costs £1.10 per litre - that's about $8 per US gallon. And we still buy loads of it!

John
 
I didn't see any responses from Veg heads, i.e. burning salvaged vegetable oil in diesel engines. The research I have seen, although mostly from suppliers of conversion kits, indicates that you can generate the same power from veg. oil as diesel. The main problem seems to be cleaning up the oil and pre-heating before input into the engine. All of the systems that I have looked at and considered utilize a separate fuel system for the veg. oil; tank, lines, filter and pump. They start the engine with diesel, switch to veg. when its at the right temp. and then switch back to diesel at the end of the trip to purge the engine of veg. You do have to build your own refinery with a couple of drums and collect the oil from your favorite chinese restaurant. The biggest problem seems to be finding a car/truck with diesel engine. I'd like to run a pick-up truck but the only models with diesels are the F250's and Ram 2500's and these trucks just seem way to big for what I need. Any reports on what effect the veg. oil has on the engine?
thanks
 
Algae would be a good source for biodiesel as opposed to soybeans or canola. See this article:


Estimated required area to supply the USA:

"15,000 square miles (3.85 million hectares) of algae ponds would be needed to replace all petroleum transportation fuels with biodiesel"

That's a pretty large area, about four times the area of Connecticut, but still doable.
 
I can see it now: environmentalists manage to get the government to build huge algae ponds in wilderness areas and abandoned industrial centers around the US (a new use for New Orleans, and all the empty auto plants in Detroit?). The resulting super-swarms of mosquitos born out of these huge swaths of stagnant water spread out across the US and wipe out 90% of the population with West Nile.

There's always an unintended consequence - although that would allow the US to cut it's CO2 emissions. :)

Bob
 
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