Hey Paul,

What do you think of designing the coolant and oil heat exchanger systems to
be somewhat self contained and modular?  I realize that cooling issues are
getting pretty well licked on the rotary, but I can't help but think things
could be even better..

What I envision is building the inlet scoop and diffuser to attach to one
side of the exchanger, and the outlet plenum and restictor flap attached to
the other side of the exchanger.  Attach this whole assembly directly to the
motor mount.  Where exposed to heat from the exhaust, the construction would
be of metal, but otherwise composite.  The rest of the cowl would be
designed to attach to the firewall, and ot the exchanger plenums.  Louvers
would be used to provide direct ventilation for the remaining engine
components, and to reduce problems related to heat soaking after shutdown.

A couple of the benefits are:

- Direct/idealized control of airflow to/through/from the heat exchangers,
allowing smaller, lighter, and more efficient installations

- Elimination of the "pressure cowl."  A pressure cowl mandates relatively
heavy, stiff sections in order to maintain effective sealing around the heat
exchangers.  The pressure cowl must contain (withstand) the dynamic pressure
associated with ram inlet air at flight speed times the total containing
area - significant forces involved.  Additionally, since the pressurized
section involves many penetrations for controls, structure, and
instrumentation, the sealing becomes piecemeal and complex.  If the critical
pressurized sections are contained around the heat exchangers, the rest of
the cowl becomes essentially a lightweight fairing around the engine.

Another idea I had was to design the exhaust system so that much of it is
external to the cowl..  Some people would think this is ugly, but I maintain
that proper design would make it adequately aerodynamic, lower the heat load
in the cowl, make inspections much easier, and thus represent an improvement
in efficiency and safety.  I have seen quite a number of artfully designed
and constructed motorcycle exhausts that i don't think would be the least
ugly were they mounted on an airplane..


Matt-

Good idea Matt. Good write up too.

Paul Lamar