Nutating disk engine perspectives

[Stanley514]

Recently there was information that military is developing a nutating disk engine
http://en.wikipedia.org/wiki/Nutating_disc_engine"
which, as they hope, will have higher power density, than reciprocating engine.Also some people say,that this is low friction design.
Does anyone know what is pro and contra of this engine type and if it really does have low friction,could it be made of carbon fiber or ceramics,to work with no cooling and have greater efficiency?

 

[Curl]

I've seen this before. Personally I think the design is crap, there's no way it has "low friction" and the compression ratio sucks. Everyone makes stuff up about their design, like "more efficient, lighter, low friction" etc. Most of the time its garbage.

 

[Stanley514]

Do you know something about other types of engines which could be better than reciprocating?Especially those which have few moving parts and low friction?
As I see, one of main problems of reciprocating engine is unability to make it from ceramics or other heat resistant materials which are presently available.
What do you think about rotary pulse jet or rocket engine similar to this design?
http://conceptengine.tripod.com/conceptengine/id2.html"
Rocket engines have high efficiency,up to 70%.If we will enforce it to rotate around an
axle at optimal RPMs and produce electricity,will it be more efficient than gas turbine?
Or such design is nowhere close to reality?

 

[Curl]

I've seen the rotary pulse jet and its garbage. The efficiency on those is horrific. There are also about 30 rotary engines out there, most of them are also garbage.

I've seen probably 100+ unique designs of engines, both rotary and reciprocating. Most of them are trash, only a handful impressed me. For me the best design is the diesel and perhaps the two stroke diesel. Its probably the simplest design, everything else has problems with sealing/compression/friction, etc.

The truth is, there is no better way to get a volume change than a piston, its the easiest to seal and its linear and the friction only comes from piston rings which is low. Anything else will screw it up.