Eric Ruttan wrote:

Very interesting thought.  A Rotary converted to a diesel.  Why not just
mill up a higher compression rotor, slap in two of the VW TDI injection
systems (get the third injector for in cylinder diagnostics), or better

yet

the new High Tech VW PD TDI (2004 in the US, 2003 in Europe) systems and
save yourself the high pressure plumbing, and make a single rotor diesel
("Rational heat engine" is the name the designer gave it).  You could use
the TDI Brain.  There is about a dozen small company's hacking the TDI
Computer who could help you get it running.

A 75Hp single rotor diesel, made with off the shelf automotive parts,

would

about put rotax out of business I would think.

Very cool
Eric

Not that easy.
The problem is the higher the compression ratio the worse the shape of the
combustion chamber. Ten to one is about the practical limit. If you just
want to burn jet fuel no problem. Go for spark assisted direct injection
but don't expect diesel like BSFC's.

Paul Lamar

I haven?t read anything on a high compression rotary combustion chamber
shape.  What does it look like?  What is impractical about the higher
ratios?
As I understand it diesel BFSC's are a function of the BTU density AND the
high compression ratio.  At higher ratios we are able to extract more energy
out of the burn.  This was figured out a long time ago by hot-rodders.

Wasn't there a few compression ignition rotary's?  How'd they work without a
high compression ratio?

As you make the rotor depression shallower and shallower the combustion chamber
becomes a long rectangular flat volume. This quenches the fire due to excess
heat loss to the rotor and rotor housing. The ideal combustion chamber
shape is a sphere.

Rolls Royce built a compression ignition rotary wherein two rotors were
used in a compound arrangement. One rotor pre compressed the air for the second
rotor. I suspect it failed for the same reason a super charger or turbo
charger does not result in better BSFC. Too much heat loss.

Paul Lamar
 
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