I'm afraid I'm not able even to soften a bolt, but I'm somehow imaginative,
close to fantasious.  Very early research published in SAE papers and other
places, has shown that a peripheral port with an square shape, corners more
or less rounded, is better than the usual circular intake port in peripheral
intake ported engines, the Norton motorcycle engines had a rectangular
peripheral intake port, or perhaps closer to oval; if the intersection
between intake duct or manifold and stator or epitrochoid surface is
streamlined, results are also improved, the more efficient shape for this is
a parabole, an square angle gives an efficiency of around 75%, if you just
add a slope, it can improve to 80% or more, and the parabole would give
nearly 99% efficiency, there are always losses because of drag and things
like.  An intersection in right angle does produce turbulent flow, with
losses in volumetric efficiency.  The improved results with a rectangular or
square shaped peripheral port seems having been more noticeable in high
speed, no big rpm fluctuations engines, that is the kind of use an aircraft
engine would have.

Theoretically, tilting the angle of the main intake duct line in a different
angle than perpendicular or parallel to the rotor long part of its surface,
considered for this also as a rectangle, may allow generating inside the
combustion chamber any desired degree of turbulence or swirl, that can be
adjusted to improve combustion.  Harry Ricardo attributed to this swirl some
of the advantages of his line of single sleeve-valve engines, that were
among the top in power, reliability and fuel economy of all reciprocating
aircraft engines of WWII.

However, it seems that turbulence inside the combustion chamber is a double
edged sword, too much may be close to detonation, may be, and the
determination of the right degree of turbulence within the combustion
process for every possible combination of rpm, throttle opening and other
settings in an engine intended for aircraft use may be expensive both in
terms of money and in time, and probably there are so many variables
involved, that evaluating all posible combinations is only at the reach of
big companies.

I beg your pardon, these comments are at a high school level, or even for
younger people, not for men seriously involved an experienced in the field
of aircraft RCEs, but it's the level of my comments in aaroncake.net and in
some articles in Wikipedia, so if you have the time and the envy for this,
I'll appreciate any feedback on these concepts.


Have a nice weekend, best regards, salut +

Jose Gros-Aymerich
Madrid, Spain

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