As with all new engine proposals, it only becomes relevant after they can produce a working example at power outputs usable in the real world that meets all requirements.

Does this design solve the pollution problem associated with 2 stroke engines?
I thought the 2 stroke is a dying engine (except for chainsaws and unique applications) due to it's high pollution of burning oil mixed in the gas?

A very well-thought out engine concept that has inherently much lower friction than trational piston-crank 4-stroke cycle engine.

Coupled with the inherent variable compression mechanism and Kadenacy uniflow scavenging mechanism taking advantage of the inertia of the exhaust gas, along with the variable exhaust valve timing in the compression stroke in order to throttle the air intake charge without require a power-robbing negative-pressure throttle plate, partial-load efficiency will be much better than traditional gasoline engine and even diesel engine, given the much lower internal friction level.

Peak efficiency will probably be no more than about ~15-20% higher than of the best of current optimized 4-stroke cycle engine due entirely to reduction in friction, BUT, partial-load efficiency can easily DOUBLE the best of current engines, given the lower friction level, variable compression, and the extended time in the cycle for exhaust, scavenging, and combustion.

Conceptually, this engine operates similarly to the 2-stroke Detroit Diesel or Orbital 2-stroke GDI, but it has much improved scavenging mechanism, much improved flow, and even lower internal friction due to the use of one large annular piston replacing 2-3 smaller pistons having much larger side-wall surface subjected to friction loss. However, some oil loss from the piston rings to the intake air on the upward compression stroke may be inevitable, and unless this oil can be burned completely within one combustion cycle, higher HC emission may be possible. The longer combustion duration when the piston is at TDC may help in this respect.

The high heat in the combustion chamber may impair lubrication of the "Guillotine" exhaust valve sliding up and down on the inner surface of the cylinder head. Perhaps some advance tribology method may be required to overcome this issue.
Of course, more problems may surface during further development process, but so far, this concept looks very promising.

darwin,
No oil and gas mixing required here. Lubricating oil can be sprayed on the lower cylinder when the piston is near TDC.

Kerry,
If one can make a H2-ICE-HEV that can match the efficiency of electrical generation and transmission via the grid, then why bother with plug-in charging nitely and expensive and heavy battery?

Instead of burning the coal, natural gas or waste biomass to generate electricity, one will just need to convert these directly into H2 via gasification process at even higher efficiency than electrical generation. Then, if the FC-HEV or super-efficient ICE-HEV can utilize the H2 with an overall efficiency from-source-to-wheel higher than BEV, one can forget about low-cost battery development. A 1.5kwh of battery capacity per HEV will be all that will be needed.

What to do with solar and wind electricity? Just feed it directly to the grid, while conserving coal, natural gas, or waste biomass to generate H2. Do not make H2 from electricy using normal-temp electrolysis of water, because this is an expensive and inefficient way to produce H2. 4kg of H2 energy can be stored in mobile tanks 160-liter size at a BEV-equivalent capacity of 115 kwh, with the cost the storage tank of ~$2000 USD, for a range of 300 miles. Fuelcell costing too much? Possible! Now, do you see the beauty of a low-cost superefficient ICE? Try to calculate how much it would cost for a BEV with that much battery capacity?

GreyFalcon,
I have debunked Ulf Bossel's defamation of the Hydrogen Economy many times here in GCC.

His assumption is that H2 will be produced by room-temp electrolysis of water using electricity from either the grid or wind or solar. He is correct to say that H2 produced this way will give H2-Vehicle 1/2-1/3 the efficiency of electric BEV.

But, commercially, H2 is not produced by electrolysis of water. It is produced by steam reformation of natural gas with about 70% efficiency, or even higher when the resultant heat will be recycled into electricity production. Gasification of coal or waste biomass can produce H2 at comparable efficiency as from natural gas.
In contrast, a Combined-cycle natural gas power plant is rated at 55-60% efficiency. Coal-fired powerplants has 35-40% efficiency. Distributon of this electricity through the grid cost 8% of the energy in the electricity.
If the H2 is produced locally, distribution of the H2 locally within a 15-mile radius only cost 3% of the energy within the Hydrogen. If the H2-Vehicle is fueled right where the Hydrogen is produced within the city limit, the cost of distribution will be even less. Compression of the H2 will cost ~7-9% of the energy of the H2, but a substantial portion of this energy is recoverable to do useful work, for example, to run accessories in the vehicle. See theaircar.com website, in which a car is run entirely on compressed air.

Finally, a FCV like the latest Honda FCX was quoted by Honda to have 60% efficiency tank to wheel. A BEV is recognized to have about ~70% efficiency grid to wheel, factoring in losses in the charger, battery's internal resistance, heat production in power semiconductors and in the motor, requiring liquid cooling, and battery self-discharge.

So, for H2-V: 70% x 94% (distr+compressn)x60%= 39% source-to-wheel efficiency!
For BEV: 55% x 92%(distribution)x70%= 35% source-to-wheel efficiency! Note that coal-fired electricity will result in even lower overall efficiency for BEV, but I am a kind person.

What about wind and solar electricity? Don't bother to make H2 with them. Just feed them to the grid and save the coal or biomass for H2 generation. There will be plenty of waste biomass to serve as H2 source to meet all transportation need.
In the future, high-temp electrolysis for H2 production, having twice the electrical efficiency of normal temp can be used, using the waste heat from biomass or coal gasification, will make wind and solar electricity H2 equally efficient as BEV from renewable electricity.

Ben,
Good question. That's why a very efficient ICE but low cost, with peak efficiency approaching that of the Fuel Cell would be a great alternative. Don't dismiss the ICE as yet, that's the gist of this discussion. Development on the FC front is also promosing, with prediction that cost of the FC stack can be reduced to $4000 USD/vehicle eventually. GM and Honda have plan to put FCV in limited production by 2008.

Infrastructure for H2? Very simple. Put a gasification plant for every 10 x 10 =100 square miles of urban area, and then each vehicle will have to travel but 5-7 mile one-way trip to fuel up, initially. No need to put H2 into tankers to travel down the road. Definitely not a station every street corner like we have for gas station now, but such is a waste and not really necessary. When more H2 vehicle will show up, there will be sufficient commercial justification for additional pipelines to conduct H2 from these plants to the more local stations.

Honda has a device whereby you can make H2 from home from natural gas, if you happen to live too far away from a H2-filling station. This device also provide heat for your hot water and home heating also, I would presume, from the exothermic reaction of NG to H2 conversion, thus higher efficiency of conversion than calculated when waste heat can be utilized.

Expect that H2 will cost the same as gasoline now for an equivalent energy content, but H2-Vehicles can travel twice as far as gasoline vehicles, so you can bet that you'll pay 1/2 as much for energy cost to travel the same distance. This energy cost saving will pay for the higher initial cost of the H2-capable vehicles.

hydrogen powered turbines with high speed alternator/generators are the best bet. anyone with water and electricity can make their own fuel. my company will be developing hybrid turbogensets for vehicles in the next year or so, but 500 mile range systems will cost about $50k. roughly 80% efficient with a 90% efficient turbine, 95-99% efficient mechanical to electric conversion, and 96-98% efficient power conditioning. The main advance will be in ultra efficient liquid hydrogen and liquid oxygen production.