Turbocompound engine

[GasSavers_Shrek]

I was wondering, has anybody/automaker tried to see if the turbocompound engine works
fyi: turbocompounding is basically putting an exhaust turbine on the snout of the crank and basically getting free horsepower (so far as i know) but don't know about fuel milage

[Sludgy]

A Wright radial aircraft engine was developed using turbocompounding. It was installed in some very big planes. There is a discussion on Wikipedia.

http://en.wikipedia.org/wiki/Wright_R-3350

Turbocompounding increases efficiency at full load, good for planes, but lousy for cars. Automobile engines rarely operate at full load. Part load efficiency in cars could suck, because a turbine would have to be sized for full exhaust, but mostly operate at a fraction of full load.

It might be cost effective to drive auxiliary systems like the alternator and water pumps using a small turbine downstram of the catalyst. It would have to be equipped with a byapss (wastegate) to allow full power without restriction.

[GasSavers_Pete]

Shrek,
Short answer is NO.
Commer in the UK in the 1960's did experiment with a Turbo Compounded two stroke diesel but found
a) it was too expensive
b) it gave no real world advantages and
c) it met with what might be termed "consumer resistance" (in other words the main target customers would not consider it.

Napier fitted their engines with T/C at various times during the 1940's and 1950's but came to the same conclusion Commer did.
Napier also found turbines more viable for the real world (they run on kerosene not 120+ octane AVGAS) and by the time the Nomad engine was sorted it was obsolete.

LJK Setright wrote several books on the topic if you can find them.

Peter.

[GasSavers_Pete]

Some of the titles for LJK Setright's books:
"Supercharging and turbocharging for maximum torque" , and
"Some unusual engines"

Peter.

[kamesama980]

What I read whilst researching a class project is that it works good for steady RPM, not-too-wildly-fluctuating load like a generator or other stationary engine. that being said, it's expensive and complex gearing-wise.

[GasSavers_Pete]

Yep , great for things like aircraft and marine engines where 90%+ of the operating time is at a constant speed and load but not the best option for variable load and speed applications like truck engines etc.

Aircraft and marine engines have a higher initial cost as well so the extra cost needed is usually viable given the operating parameters.

Servicing and maintenance requirements also play a part as the demands for keeping a T/C engine are greater than most car engines.

Napier's Nomad engine was both powerful and frugal but was an absolute pig to get running and required higher servicing talents and facilities than most aircraft operators were willing to invest in.

Commercially the Wright Cyclone engine won hands down.

Peter.

[trollbait]

It might work for a battery serial hybrid in a commercial truck.

[Sludgy]

Right on cue, Ricardo has announced electric turbocompounding.

http://www.ricardo.com/News--Media/P...ectrification/