Mature TL8 car engine?

[pawsplay]

http://www.msnbc.msn.com/id/42460541...e=home_oneline

"The Wave Disk Generator uses 60 percent of its fuel for propulsion; standard car engines use just 15 percent. As a result, the generator is 3.5 times more fuel efficient than typical combustion engines."

[Sunrunners_Fire]

Originally Posted by pawsplay

http://www.msnbc.msn.com/id/42460541...e=home_oneline

"The Wave Disk Generator uses 60 percent of its fuel for propulsion; standard car engines use just 15 percent. As a result, the generator is 3.5 times more fuel efficient than typical combustion engines."

Neat. I'd love one. Looking at the prototype's physical profile, I wonder if it would change the car's appearance ... something to put under the vehicle rather than in front of it?

[pawsplay]

Plus, Wave Disk Generator is a completely awesome name.

[Purple Haze]

Standard internal combustion engines do better than 30% efficiency. So this isn't doing more than 2x the efficiency.

Worse this is only suitable for hybred style cars so it will be charging batteries to drive electric motors which are at best 80% efficient. So we're down to about 1.5x.

Then hybreds only make economic sense to the consumer because they are heavily subsidized. The current generation of owners are going to get a rude supprise when it comes time to replace their batteries.

This will be a niche product at best.

[Langy]

Originally Posted by Purple Haze

Worse this is only suitable for hybred style cars so it will be charging batteries to drive electric motors which are at best 80% efficient. So we're down to about 1.5x.

Why is this only suitable for hybrids? Also, electric motors get about 90% efficiency, not 80%. Still, you're correct - it's 'only' going to give about 1.5 times the mileage of a gas engine with 30% efficiency. Mind you, most automobile engines have about 20% efficiency, not 30%. They've got a theoretical limit of 33%, but that's not going to be hit.

The reduction in weight would result in a much higher efficiency increase, too, by the way.

Then hybreds only make economic sense to the consumer because they are heavily subsidized. The current generation of owners are going to get a rude supprise when it comes time to replace their batteries.

This will be a niche product at best.

Yeah, that is one of the main problems with hybrids at this point in time. Still, gas prices are going up, and are only going to continue going up, so hybrids are still a good idea.

[Anthony]

A number of unspecified features of this engine; it's not as big an advance as it looks like. A large part of the reason for low efficiency for automobile engines is that they have to run at highly variable speeds and power levels, and have fairly high power density (automobile engine efficiency actually varies quite a bit depending on where you are in the cycle); a marine diesel (with much more lenient performance requirements) can achieve 50% efficiency, and commercial cogeneration systems can achieve 60%, though not in a design that's at all viable for a car.

One fairly common hybrid theoretical design is to connect a high efficiency constant speed engine to a generator and feed electricity into the drivetrain, or batteries under certain conditions; this is the principle behind the diesel-electric train. The comment about having no transmission or crankshaft tells me that this is the way this engine is intended to be used (there's a pretty good chance that a next-gen automobile will work this way). Whether this particular engine will prove viable depends on actual achievable efficiency, power density, and price, as compared to competing systems. The fact that it's currently being funded by the DOE as opposed to private industry tells us that the technology has a ways to go.

Originally Posted by Purple Haze

Standard internal combustion engines do better than 30% efficiency.

Maybe in a very limited range of speeds, but in regular operation efficiency is lower (though I'd still say 20%, not 15%). There's a reason city MPG is lower than highway MPG; low speed efficiency is kinda lousy.

Originally Posted by Langy

Why is this only suitable for hybrids?

It's highly probable that this engine doesn't have the range of speeds and torque required for an efficient conventional transmission.

[vierasmarius]

Originally Posted by pawsplay

Plus, Wave Disk Generator is a completely awesome name.

This on it's own is enough to make me want to use it as the standard biofuel engine for TL9 economy cars.

[starslayer]

Plus no video of the damned thing running, just him holding a CAM printed model- so as of right now it's a theroy only. The description for this device is somewhat similar to a jet turbine. Jet turbines are actually really fuel efficient, but they have stupid high tolerances, break easily, are only good at there ideal RPM, are costly to build, and require regular maintenance.

Another very big potential efficiency-boosting technology that people have been looking at is a sterling-engine wrapped around the ICE to extract the 'wasted' heat- the issue is what do you do with the extra energy? (since the engine must be hot before the sterling engine will engage you can't make it propel the vehicle because then it won't be able to move until the engine heats up, it could potentially charge batteries, but then what about a cold day, etc)

Jaguar and other companies are looking into turbine driven generators for electric propulsion now which may be functionally similar to this.

[Anthony]

Oh, I just checked. The Prius engine, at its peak efficiency (about 12 kW/20 horsepower) achieves 37%, and it beats 30% in the range of 5-45 kW. Figures according to Argonne National Laboratory (page 11-12). That's a more realistic comparison than a 1970s era engine (which did have 15% efficiency).

[Anaraxes]

The diagram looks something like a rotary engine, except instead of the driveshaft, they make it an electric generator.