Re: [ihc] no IH content, but fun--

[Steven Stegmann <steve.stegmann@xxxxxxxxxxxxx>]

Ryan,

I sure wouldn't want something that complicated in a
car, let alone an airplane.  I agree completely.

It still is a fascinating engine.  BTW there were
several variants in the way the turbines were handled.
 I have some pix and will try to find a few minutes to
check out the differences.  Seems like there was one
with a mechanical supercharger and an exhaust turbine
connected to the output shaft.  Not sure about that.

Also, I'm sure that one could take a large truck
engine and put another exhaust turbine and capture
some work and gear it to the crankshaft.

What makes the Napier so amazing is not the combined
cycle, all sorts of these have been used.  They tried
to put it all into one casting so it would fit in an
aircraft.  Doing it with separate parts and piping
them together, like a commercial truck engine, would
be much easier.  And we now have compters to control
the whole mess, and they work.

Steve


--- Ryan Moore <baradium@domain.elided> wrote:

> I have a picture (that I believe is a bit better) of
> that engine on my
> computer.  I did a report on it once.
> 
> You have the description off, I'm afraid.
> 
> It's a12 cyl, horizontally opposed, direct injection
> diesel engine (I'm
> touching on the turbocharged part next).
> 
> The turbine and piston engine sections *are*
> mechanically connected through
> a very complex series of gears.  That turbine *also*
> provides the
> turbocharge for the diesel piston engine section.
> 
> You also saw *the* Napier Nomad.  There is only a
> single engine around, and
> that's it.  The rest were destroyed, they never
> actually did flight test one
> (came really close once, it was even fitted to an
> aircraft, but then they
> scrapped the program).
> 
> The Napier nomad has a thermal efficiency
> approaching 60 or 65%.  But if you
> saw the design layouts for the motor (I have), you'd
> understand why it
> failed.  One thing you don't want in an airplane is
> complexity.  The more
> complex something is, the more little things can
> break to mess the whole
> thing up.  That's one reason you don't see a lot of
> Wasp Majors floating
> around.
> 
> Although the Nomad was very efficient, they could
> not find a single buyer
> willing to run something so complex.
> 
> The Nomad also has provisions for an afterburner
> (although I think that was
> just an afterthought).  The Napier Nomad is *the*
> most complicated engine
> ever designed.  (I did research on other Napier
> engines at the same time).
> Very efficient, but not something you'd want to work
> on or be flying with,
> unfortunately.
> 
> One of the most interesting designs of a Napier
> motor in general (other than
> the nomad) is a 24 (or was it 48?) cyl "triangle"
> engine.  In this engine
> there are three crankshafts mated to one output in a
> triangle fashion.  The
> three crankshafts share three cylinders with two
> pistons per cylinder.  This
> engine is a prime mover engine for locomotives and I
> believe there may still
> be some in operation in Europe.  *very* fun to work
> on from what I found.
> 
> They also made 3 row inline engines... three
> crankshafts that were basically
> 3 long engines sharing the same block with a single
> output.  Supposed to be
> VERY fun to try to get running right.
> 
> Anyway, I can't find the links I have of them. 
> There's a book in our campus
> library that deals a lot into the Napier engines,
> that's where I saw the
> charts for the nomad.  Scary.
> 
> -Ryan
> 
> 
> ----- Original Message ----- 
> From: "Steven Stegmann"
> <steve.stegmann@domain.elided>
> To: "Greg Hermann" <bearbvd@domain.elided>;
> <jma@domain.elided>;
> <ihc@domain.elided>
> Sent: Tuesday, October 26, 2004 06:36
> Subject: RE: [ihc] no IH content, but fun--
> 
> 
> > Greg,
> >
> > Did you ever hear of the Napier Nomad diesel
> aircraft
> > engine.  I saw one at the Smithsonian Udvar-Hazey
> > center at Dulles Airport.
> >
> > Turbocharged diesel, with a second turbine whose
> > output was combined with the shaft drive to the
> > propeller.
> >
> > http://en.wikipedia.org/wiki/Napier_Nomad
> >
> > Steve
> 
> 
> 
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