contents of this page are
from "ELEMENTS OF FRASCA ROTARY ENGINE DESIGN*"
OF THE BASIC
ENGINE ELEMENTS AND OPERATION
*Copyright © 1998 by Joseph F. Frasca
To familiarize you with the
a brief discussion of the Frasca rotary engine, and its operating
along with a glossary of terms follows.
of this page
are from "ELEMENTS OF FRASCA ROTARY ENGINE DESIGN*"
© 1998 by
Joseph F. Frasca
COMPRESSION RATIO : is a VVC's
Chamber; i.e. working chamber) maximum to minimum volume ratio in the
undulation of a FRE (Frasca Rotary Engine).
It is also the maximum to minimum
of a VVC in the combustion undulation of a non-tuned FRE
DUMP PRESSURE: is the pressure
of the VVC immediately
before communication with exhaust porting.
The higher the dump pressures the
the noise generated by the sudden gas expansion in the exhaust system.
EXPANSION RATIO: is the maximum
volume ratio of a VVC in two cycle engines.
It is also said ratio in the
undulation of a tuned 4 cycle FRE.
FACE SURFACE: is the annular
of the engine casing.
FRE: Frasca Rotary Engine.
GAP: is the clearance between
edge at the rotor wave surface and the wave surface.
PGAP: is the clearance between
and its slot at the engine annular cavity and the clearance between
moving surfaces at the inner and outer circumference boundaries of the
PURGING: occurs in the engine
with an air intake(s)
(scoop) on its rotor which supplies fresh air to VVC in the FRE annular
cavity exhaust region(s). The fresh air cleans the VVC, completes
gas combustion and cools the VVC.
TUNED ENGINE: is 4 cycle FRE
that has a maximum
to minimum VVC volume ratio in the compression undulation that is
from said ratio in the combustion undulation.
In usual circumstances the ratio
will be larger
in the combustion undulation to permit lower dump pressures and
and increased power .
VVC: is Volume Varying Chamber.
The VVC are the FRE's working
WAVE SURFACE: is the annular
on the engine rotor.