Why hasn't the internal combustion engine been replaced?

[dandrews02]

Why hasn't someone invented an engine capable of turning a driveshaft to replace the internal combustion engine?

We can do work in nano seconds and hold gigabytes of information in our palms, but we are still dependent on 1860's technology?
Enviormental concerns and oil issues aside, aren't we well past due for an engine upgrade?

[engineer_comp_geek]

Not only does it have to be more efficient than the internal combustion engine, but it either has to run on the same fuel or it has to be so much better that it's worth investing in the infrastructure required to make it practical for everyone.

That's a taller order than just building a better mousetrap.

[dolphinboy]

The laws of physics haven't changed much since 1860. You still have to figure out a way to safely generate enough energy to move a 2 ton object at 70 mph for many hours at a time.

Hydrogen fuel engines may be the wave of the future... but safely combusting, transporting and producing hydrogen isn't a walk in the park. For the record, there are alternatives to the IC engine, like electric motors or steam engines, but neither has the range or safety factors on an IC engine.

I recently bought a hybrid which uses fancy computers to figure out when to tax the engine and when to tax the batteries. At best it is more fuel efficient than a standard configuration. At worst it's heavier and has less performance than its standard counterpart... and costs $2K more to boot.

If you have a better engine idea we would all love to hear it!

[FatBaldGuy]

Talk about outdated technology, why are we still using wheels and axles? That idea's been around since the stone age.

[Philster]

Still using arabic letters to communicate over the internet....in 2006!?

Hey, gasoline is economical.

Believe it, or not.

The economy of a gas fueled world (and diesel of course)...there has yet to be a model to topple the economics of it all.

Forget technology. Think economics.

[awldune]

Originally Posted by Philster

Still using arabic letters to communicate over the internet....in 2006!?

Roman letters. Arabic numbers.

[spingears]

Originally Posted by dandrews02

Why hasn't someone invented an engine capable of turning a driveshaft to replace the internal combustion engine?

It is NOT for lack of trying. A great deal of effort & $ has been expended to create such a beast. To date the ICE is the best available whether gasoline or diesel oil.

Enviormental concerns and oil issues aside, aren't we well past due for an engine upgrade?

I agree we are well overdue.
Much effort has been put into the basic Stirling engine concept and the more general Hot Air Engine embodiment of the Stirling.
Hot air engines in general have major problems of introducing heat energy into and out of the engine and lack of means to control the speed.
Solve those two problems and you will have it 'made.'

Stirling engine Photos

Modern Repro of KYKO Stirling Fan
Hi-Tech Version of KYKO Stirling Fan

Links to Stirling Sources
More Stirling Links


Stirling Engines
Stirling Engineering

Some Stirling Theory

Note: Some of the links may be out of date or broken.
spingears Dec. 2005

You might get the idea I am interested it the overall subject of HAE's!

[Xema]

Originally Posted by dandrews02

Why hasn't someone invented an engine capable of turning a driveshaft to replace the internal combustion engine?

Someone has, as spingears notes. The Stirling engine was patented in 1816, so it's substantially older. But the IC engine rather soon established a lead that the Stirling engine hasn't managed to overcome.

One of the problems is that the IC engine is a moving target. Countless billions have been spent on its development, and it keeps improving.

What do you feel are the ICE shortcomings which the hypothetical new-technology engine will overcome?

[Patty O'Furniture]

What do you feel are the ICE shortcomings which the hypothetical new-technology engine will overcome?

More efficient conversion of energy into torque at the crankshaft.

[Xema]

Originally Posted by Patty O'Furniture

More efficient conversion of energy into torque at the crankshaft.

Modern ICEs can be very efficient. This site shows one that achieves thermal efficiency better than 50% - quite remarkable for a heat engine. (Admittedly, you're not going to see this in an SUV anytime soon.)

[kelly5078]

Too bad. I'd love to say my car has a Wartsila-Sulzer powerplant!

[Tuckerfan]

Don't forget that it would cost a bloody fortune to convert manufacturing plants over to the new engine, modify existing car designs to accept the new engine, train assembly line workers on how to put the engines together, train the service staff at dealerships, train the sales staff, edumicate the public on the new wonder engine, and get it certified by the Feds. Unless the replacement for the ICE is bloody phenominal, it's not worth the cost of switching.

[Philster]

Originally Posted by awldune

Roman letters. Arabic numbers.

So stvpid I am.

[633squadron]

Originally Posted by dandrews02

Why hasn't someone invented an engine capable of turning a driveshaft to replace the internal combustion engine?

We can do work in nano seconds and hold gigabytes of information in our palms, but we are still dependent on 1860's technology?
Enviormental concerns and oil issues aside, aren't we well past due for an engine upgrade?

Plenty of people have invented systems that replace the internal combustion engine. A lack of invention is not holding us back from better propulsion systems for cars, or even other methods of transportation. As others have pointed out in this thread, we have more problematic barriers to replacing the ICE and the automobile.

Even if someone came up with a four-wheel vehicle that looked exactly like a car, ran on water, and cost $50 to make, it would take a fair amount of time for everyone to replace their existing cars. With hydrogen fuel cell technology, the issue is nowhere near that simple, so I'm not holding my breath!

We can do calculations in nano seconds and hold gigabytes of information in our palms because we've driven down the cost of making automobiles, ICEs, and the fuel to run them. If we focused all our energies on changing over from ICEs to something else, we wouldn't have many of the things we take for granted that allow us to have the rest of modern technology.

There ain't no "intelligent design" in any of it. Stuff changes and improves somewhat over time, and then sticks in one place unchanging. Heck, we still have watches with faces and hands, that tell time in multiples of 60. If we can put a man on the moon, can't we come up with a decimal system of time (this is a rip-off from another SDMB thread that I'm now too lazy to go find)?!

Other examples of "why the heck are we still using...":

• Typewriter keyboards for input into computers
• For that matter QWERTY keyboard layouts
• Big, expensive, fragile, energy-gulping picture tubes for computer *output*
• A seemingly random sequence of digits to call someone on the phone
• A wheel to steer cars, instead of a little joystick
• Books made out of paper

[kanicbird]

Modern ICEs can be very efficient. This site shows one that achieves thermal efficiency better than 50% - quite remarkable for a heat engine.

To go into a bit of detail here a heat engine converts chemical energy to heat, and work is extracted from that heat.

Whenever you take useful energy from heat there are losses, you can never approach 100% efficiency this way, more like 50% max (using frictionless surfaces and massless pistions). In a light weight package, over a range of power, the IC engine does darn good, add to that the durability of it and it would be hard to find something to surpass it.

The big promise is an engine that can take chemical energy and convert it right into another non-heat energy. Like fuel cells can go from chemical to electrical. In theory this can approach 100%. For now these technologies are too expensive either in the engine manufacture, the fuel source or both.

[Raguleader]

Originally Posted by dolphinboy

The laws of physics haven't changed much since 1860. You still have to figure out a way to safely generate enough energy to move a 2 ton object at 70 mph for many hours at a time.

Hydrogen fuel engines may be the wave of the future... but safely combusting, transporting and producing hydrogen isn't a walk in the park. For the record, there are alternatives to the IC engine, like electric motors or steam engines, but neither has the range or safety factors on an IC engine.

I remember having it pointed out to me in a History of US Seapower class that all ships have been essentially using the same type of engine since the early 1800s. Whether it uses a paddlewheel or a screw, pistons or turbines, coal, diesel, jet fuel, or Uranium, practically all ships use steam engines. The only thing that changes are how you MAKE the steam, and what you DO with the steam (including some novel concepts, such as using the steam to physically toss airplanes off the end of the ship with a catapult)

And despite many great advances in technology, including buckles and velcro, the most modern militaries in the world still have their soldiers keep their boots on their feet with lengths of string tied in a knot.

[R. P. McMurphy]

I know a guy that works on the hydrogen car project for a major auto manufacturer. While explaining some of the techical problems he faces he made a few non-technical observations which I found interesting.

First, he said that gasoline is THE most efficient method of storing energy. It's cheap, available, transportable, relatively safe to handle, and packs a whole lot of potential energy in a small space. While gasoline is has its disadvantages, it is proving to be a formidable task to develop something that, on balance, is a improvement.

Second, hydrogen is difficult to store. It tends to just disappear. If you have a vehicle that can't be left for a month and still be able to run, you don't have a very reliable vehicle.

While it seems frustrating that the IC engine isn't in the museum of antiquities, there are aspects to it that are hard to beat. Hopefully, technical advances will eventually render it obsolete but if it doesn't become obsolete it won't be for lack of trying.

[Tuckerfan]

Originally Posted by Spartydog

First, he said that gasoline is THE most efficient method of storing energy. It's cheap, available, transportable, relatively safe to handle, and packs a whole lot of potential energy in a small space. While gasoline is has its disadvantages, it is proving to be a formidable task to develop something that, on balance, is a improvement.

Second, hydrogen is difficult to store. It tends to just disappear. If you have a vehicle that can't be left for a month and still be able to run, you don't have a very reliable vehicle.

Has he considered using aluminum to power the car instead of hydrogen?

[Padeye]

Originally Posted by 633squadron

[*]Big, expensive, fragile, energy-gulping picture tubes for computer *output*

Many of us have already abandonded CRT monitors but they still have potentially better color reproduction for editing photos.

[*]A wheel to steer cars, instead of a little joystick[/list]

Because it provides force and visual feedback on steering conditions and wheel position unlike many small stick fly by wire systems. Airbus learned this the hard way when a plane on a demonstration flight crashed just after takeoff. The pilot pulled back on the stick but the plane's computer was set to landing mode and ignored the control input but the pilot had no immediate indication of that. Well other than his plane crashing into a forest rather than climbing. For this reason Boeing's fly by wire system uses normal full size control yokes that the pilot has to physically move (and that the computer will move back if it is taking control) rather than mini side sticks that work by pressure.

[Tuckerfan]

Originally Posted by Padeye

Because it provides force and visual feedback on steering conditions and wheel position unlike many small stick fly by wire systems. Airbus learned this the hard way when a plane on a demonstration flight crashed just after takeoff. The pilot pulled back on the stick but the plane's computer was set to landing mode and ignored the control input but the pilot had no immediate indication of that. Well other than his plane crashing into a forest rather than climbing. For this reason Boeing's fly by wire system uses normal full size control yokes that the pilot has to physically move (and that the computer will move back if it is taking control) rather than mini side sticks that work by pressure.

You can see the video here. It's pretty danged funny, IMHO.

[DougC]

- - - Electric motors are better in theory than gasoline engines. Electric motors can operate from zero RPM and many types can operate in both directions of rotation. There have been "demonstrator" cars built that used a motor mounted inside the hub of each wheel, eliminating the need for any sort of mechanical transmission or driveline, and in that system it would even be possible to use the electric motor for either active or regenerative braking, eliminating the need for conventional brakes as well. The practical problem with electric motors is that nobody has yet found a really good way to store lots and lots of electricity without resorting to using a conventional combustion engine as a generator.
- As to why we still use piston engines for IC, it's because compared to what's available, piston engines have a fairly-wide RPM range that they can operate at, and their powerband can be spread over a fairly-wide part of that range, as well as easily be engineered to peak at some specific RPM if need be.
......Turbine engines can be more efficient, but because their compression and exhaust stages are "unsealed", only at one speed--their efficiency basically increases with RPM, so they are operated at very-near their top RPM limit, up around 95% is usually the duty RPM rating--and at lower speeds their fuel efficiency drops WAY off. They are essentially considered to be single-speed engines.
.......Rotary engines (as used in the RX-series of cars by Mazda motor company) are more efficient than piston engines by some measures but are also considerably more expensive to produce, and they have a few mechanical weaknesses unique to them. If rotary engines were better on all criteria, Mazda would be using them for all their cars.
~

[Bryan Ekers]

What's fire done for us lately? Unholy pagan stuff, it is.

[R. P. McMurphy]

Originally Posted by DougC

- - - Electric motors are better in theory than gasoline engines. . .
- As to why we still use piston . . .
......Turbine engines . . .
.......Rotary engines . . .

1.) Which is the reason for all of the work on the hybrid technology.

2.) Until we come up with something better.

3.) Chrysler tried to develop a turbine car. One huge problem was the amount of heat they give off. On a side note, when the military developed a tank with a turbine engine the heat signature made it a sitting duck for a technologically advanced enemy.

4.) Correct me if I'm wrong but I thought that a major limitation of the rotary was fuel economy. Performance was good but they sucked a lot of gas. Also the combustion chamber seals wore out which is a very expensive maintenance and repair consideration.

[Hoodoo Ulove]

Originally Posted by Spartydog

4.) Correct me if I'm wrong but I thought that a major limitation of the rotary was fuel economy.

Right. The combution chamber has a very high surface to volume ratio, thus greater heat losses. But don't say "was"; Mazda is selling them again.

[Tuckerfan]

Originally Posted by Spartydog

3.) Chrysler tried to develop a turbine car. One huge problem was the amount of heat they give off. On a side note, when the military developed a tank with a turbine engine the heat signature made it a sitting duck for a technologically advanced enemy.

Which Chrysler turbine car? The 1963 model? Or the 1981 model which was scheduled to go into production until the Feds ordered the program killed.

When the Corporation was in such dire straights, back in 1979, we all know what happened, or do we?

Chrysler got some loans from the US Government...that much is certain. That Chrysler (as a condition of those loans) had to sell off Chrysler Defense and the M1 turbine-powered tank program is somewhat lesser known, but still public knowledge.

What is known only to a priveleged few is that the government killed a dream of a lifetime for a group of 70 people at the Chrysler "skunkworks" in Highland Park.

Believe it or not, Chrysler was days away from making a production decision (one which Iacocca favored) on a rather unique vehicle....

1981 Chrysler New Yorker Turbine car (M-body)... the car was ready to be tooled according to the head of the program, Mr. George Scheckter, whom I met when I got to see and touch the 1963 Turbine Car again in 1989. There was no more design work to be accomplished, just tool and start production.

The Turbine Engine was a fifth generation (not a 3rd generation like the 1963 car) engine capable of 22mpg in the EPA test cycles. To really make this sink in, one of the prototypes is still in existence (at least it was in 1989), stored in the same building as the 1963 car, its tooling and all the remaining spare parts (enough to build 3 more of the '63 cars).

Your government thought it was too much of a risk and ordered the car cancelled as "too risky, from an economic standpoint." Just imagine what COULD have happened!

(emphasis in the original)

4.) Correct me if I'm wrong but I thought that a major limitation of the rotary was fuel economy. Performance was good but they sucked a lot of gas. Also the combustion chamber seals wore out which is a very expensive maintenance and repair consideration.

I think you're right about the fuel economy standpoint, but I also believe that Wankels tend to have higher emission levels as well.

[robby]

Originally Posted by Raguleader

I remember having it pointed out to me in a History of US Seapower class that all ships have been essentially using the same type of engine since the early 1800s. Whether it uses a paddlewheel or a screw, pistons or turbines, coal, diesel, jet fuel, or Uranium, practically all ships use steam engines. The only thing that changes are how you MAKE the steam, and what you DO with the steam (including some novel concepts, such as using the steam to physically toss airplanes off the end of the ship with a catapult)

There are indeed ships being used today still powered by steam. The nuclear submarine I was on had a steam plant. I'm sure there are still some fossil-fueled steam plants out there as well.

However, most new non-nuclear ships have nothing to do with steam. These include the common diesel power plants, and the fancy gas-turbine ships.