In the Winter 2006 Issue of
The Szydlowski-Planiol S-39 Supercharger
Just
before the outbreak of World War II, an interesting variation of the centrifugal
supercharger was developed by the Turboméca Company in Paris for use on (in the
first instance) high-power aircraft engines in French Air Force pursuit
(fighter) aircraft. The supercharger was named after its inventors rather than
the company producing it and was thus called the Szydlowski-Planiol S-39 H 3.
Aero Engine Drawings by Frank Munger
The Impact of the Engine on the Airframe
Schedule Effects—German Jet Engine Development in WWII
Part 1: The Engines
Aircraft
engine development requires more time than does airframe development, usually
about 60 percent more. This truism is sometimes forgotten in the desire to
achieve program goals. Perhaps the most dramatic example of the consequence of
such forgetfulness occurred in Germany in World War II when the jet engine
not-so-quietly arrived on the scene. Two airframe companies experienced
particularly difficult effects of engine unavailability—Messerschmitt, with the
Me 262 fighter program ultimately being designed around four different engines,
and Horten, with the Ho 9 fighter flying-wing center-section having to be
revised five times to fit four different engines before it ever flew.
Gearing for Gearheads, Part 1
This
series of articles is an engineering-driven examination and appraisal of the
Rolls-Royce Merlin propeller speed reduction units (PSRUs). In order to recover
dimensions and details of the original Merlin gearsets by “reverse engineering”,
it was necessary to derive involute gear relations from basic principles.
Part 1 looks at production R-R Merlin PSRUs and extends this historical
examination to include Unlimited Racer efforts and hypothetical possibilities of
modified ratios. Particular threats facing these PSRUs in racing applications
are also explored.
Part 2 will include a description of the principles of involute spur
gearing and derivation of relations for the determination of critical dimensions
and performance factors. Also included is a look at prototypical gear failure,
its root causes and possible alleviation techniques.
Part 3 will include gearset dimensional specifics, calculated comparative
stresses and performance factors for several ratios with discussion and summary.
Table of Contents
