The Future of the Combustion Engine
http://thekojonnamdishow.org/shows/2010-06-08/future-combustion-engine
Internal combustion engines power everything from cars to planes to lawnmowers. But despite more than a century of new technology, the basic design has barely changed. We explore the challenge of making an efficient engine, and why despite the current wave of "green technology," most experts believe we'll be using the combustion engine for decades to come.
Guests
Edward Tenner
Historian of technology and culture; author of Why Things Bite Back; author of Our Own Devices; senior research associate at the Smithsonian's Lemelson Center; blogger for theatlantic.com.
Levi Tillemann-Dick
CEO of IRIS Engines, Inc.
Comments
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New inventions have been developed not just through one particular breakthrough but when other sometimes disparate developments in technologies came together. As well the combustion engine, the fuels that are consumed in the engine, haven’t changed very much. Could your guests comment on the value of fuel additives, for example, that break the hydrocarbons of diesel fuel, and reduce emissions and how these additives can improve performance and engine reliability?
I disliked how ur guest minimized the question abou hemp by turning it into a joke. Hemp is completely different, an entirely different "animal," so to speak. Hemp has many uses and yes, Henry ford did use it for his engines but was then convinced by the oil companies to use gasoline instead because it was more profitable for them.
Hemp only contains less than 0.01% thc, the substance that gets u high, whereas marijuana, can contain upto 20% thc.
So, his mother wanted him to stay away from marijuana, NOT hemp.
It seems one of the big strengths of the IRIS engine design is that virtually any kind of fuel can be used to power it. But the fuels discussed on the show were all fuels that are currently used in the traditional ICEs. One of the main technical problems of the traditional ICEs is that they all require highly refined fuels that contain virtually no particulates or non-combustible fluids (like water). It is the requirement to highly refine biofuels like ehtanol and biodiesel that compromise their feasibility both energetically (lots of energy required to process & refine) and economically.
Micro gas turbine engines may also be as efficent as the IRIS engine but the extreme heat & pressures require the fuel to be even more highly refined than traditional ICEs because even tiny amounts of particulates tear the turbine blades apart pretty quickly. This is why very sophisticated metalurgy was needed to get jet engines to work.
Has the IRIS engine design been evaluated for its ability to accept less refined hydrocarbon & bio- fuels? Does the increased efficiency of the IRIS engine design depend on higher temperatures and pressures (meaning that fuel purity is likely to be critical) than traditional ICEs? I think the IRIS engine would be adopted a lot more quickly if it could accept cheaper, less refined fuels.
Looks like a modified two stroke to me - reed valves for intake. Fuel injected I assume? Lots of moving parts too. I would like to see a working model - how are you going to lubricate the surfaces of the corbons as they rub against each other. Same problem the Wankel on the Mazda RX-8 has (had?). how are the pivot points going to be lubricated? Dry sump lubrication I guess? I don't see the ICE going anyplace for sometime - agree that batteries are too problematic and costly. Hybrids scare me - too complex. I've been a big fan of diesels over the years..........love the fuel efficiency but not the pollutants. My two cents - love the innovative effort. Thanks for a great show Kojo.
As corporate average fuel economy (CAFE) standards increase and "global warming" threatens, car makers are hustling to downsize their cars and engines and optimize the combustion process to improve mpg and reduce CO2. But they've invested lots of money and planning in existing and future engine technology and manufacturing. As your guests acknowledged, that creates lots of organizational inertia that prevents the rapid adoption of new inventions from "outsiders" like IRIS. To overcome their own inertia, car makers around the world are now adding old technology to "new" engines to quickly improve the fuel economy of their high volume cars:
- Direct injection improves fuel atomization for more complete combustion.
- Turbocharging or supercharging, or both, improves volumetric efficiency.
- Variable valve actuation (VVA) improves control of air flow to better complement injected fuel flow.
- Smaller displacement---using a 4 cylinder instead of a V6; a V6 instead of a V8, with no sacrifice in power (or with less power but made more usable by a 6, 7, or 8 speed transmission).
- Lighter, but stronger, more durable materials to reduce engine weight.
Of course the car companies are also producing small numbers of hybrid vehicles, preparing to launch limited-range electric vehicles, and doing R&D on future technology such as fuel-cell cars as well as on current technology such as camshaft-driven variable valve actuation, which many engines now have.
How much further can the "conventional" internal combustion engine be optimized to make it more efficient but still usable? Hard to say. There's still room for thinking "outside the box," but not so far out, like IRIS, that you "re-invent the wheel."
One example of optimization is super critical (heated) fuel injection from Transonic Combustion, a seemingly incremental change that, instead, will make a huge improvement in fuel economy. (No wonder Don Runkle, ex-GM, and Bob Lutz, just retired from GM, are board members):
http://www.tscombustion.com/tscitechnology.html
Another example: LIM Technology, a startup engineering company in Glen Burnie, Maryland, invented a valve that makes a camless engine possible. The basic engine is designed like a uniflow Detroit Diesel 2-stroke, for high volumetric efficiency, but reversed, so air enters through valves at the top, and exits through ports in the lower cylinder wall. The rest is like a 4-stroke. Except for the valves.
Actuating an engine's valves without the limitations imposed by a camshaft has been the goal of variable valve system designers for years. A few (Valeo, FEV, Lotus) have succeeded but their solutions are either electro-hydraulic or electro-magnetic, with each conventional valve controlled by a large "box" on top of it. A LIM valve is actuated by the normal difference in air pressure between the intake manifold and cylinder as the piston moves up and down, aided by compressed air "injected" below the valve collar at exactly the right time to completely close the valve. Depending on the application, LIM valves will be controlled by one central "box" or by one small "box" per cylinder. LIM has built three running, prototype engines, and is now developing the controls for the air-actuated valves. Copy these links into your browser to see how LIM valves work:
- in any 4-stroke engine - http://limtechnology.com/pneumodromic.html
- in a LIM Uniflow 2-stroke diesel engine - http://limtechnology.com/newhead.htm
This link is to an article about the original LIM valve and engine by John Dinkel, former editor of Road & Track, in Auto Aficionado magazine:
http://limtechnology.com/uploads/LIM%20Technology%20Auto%20Aficionado%20...
LIM Technology needs funding for their final phase of R&D. The military's SBIR (Small Business Innovation & Research) and STTR (Small business Technology TRansfer) programs offer two-stage funding for qualified startups, the first stage is for R&D which private investors prefer to avoid ! Today LIM CEO Jeffrey Klein and Chief Engineer Konstantin Mikhailov are in Huntsville, Alabama, talking to the Army about engines for UAVs (unmanned aerial vehicles).
For more info email them at jklein@limtechnology.com , or call Jeffrey at (443) 858 8546 or Konstantin at (410) 760 8801.
Downsizing, boosting and everything else HondaTechEditor talked about seems to be pretty incremental in nature. Even Transonic doesn't seem to hold nearly as much promise as their initial results suggested. The car they used for the demo is a kit car that seats two people with unrealistic CD and frontal area. The engine is a small European TDI engine that doesn't provide vehicle performance that most consumers expect and demand. The engine has not demonstrated emissions compliance and with lean operation, it will not meet the NOx limits in most developed nations without expensive and bulky NOx aftertreatment that consumes a Urea water mixture that needs filling every few gasoline tanks. Because they are running compression ignition on gasoline, the pressure rise rates far exceed what OE's and their customers tolerate from an NVH perspective. All of these issues can be resolved but not without compromising on efficiency, which is more or less true for conventional engines. I think the concept has merit, but the benefits are much smaller than claimed and it isn't clear that they will justify the cost and complexity.
As for camless engines, there have been ways to do that for years. The added cost and complexity of the systems makes them a bad investment. Is a set of extra valves and ducts really better than a cam and if it is is the improvement worth the risks associated with novelty? At least the solenoid actuated versions offer incredibly simple VVLT, I don't see LIM even offering that.
I see the future of ICEs coming from real changes and improvements (steady-state microturbines for hybrids or IRIS-like innovations) not a new set of valves.
Sorry two GM guys on the board? Bob Lutz........gotta run in the opposite direction. The people that are trying bring us the Volt? With the 53 kwh genset that sucks fuel when the battery runs dry........sorry....