<DOC>
<DOCNO>
1271
</DOCNO>
<TITLE>
theory of supersonic propeller aerodynamics .
</TITLE>
<AUTHOR>
ordway,d.e. and hale,r.w.
</AUTHOR>
<BIBLIO>
j. ae. scs. 1960, 437.
</BIBLIO>
<TEXT>
  a supersonic propeller with blades attached to an infinite cylinder
as a hub is studied .  the forward speed may be subsonic, but
the relative speed at each section is supersonic .  the lightly
loaded blades are represented by a surface distribution of appropriate
/modified/ sources in a fashion similar to ordinary
supersonic thin-wing theory .  these sources are found by approximating
the exact potential for a constant-strength compressible
source traveling along a helical path .  the usual relationship
between the source strength and boundary condition is
found,. and subsequently the source distribution is given, to the
appropriate order, in terms of the blade geometry .
  tip effects are considered by extending the theory of evvard
and krasilshchikova .  the present investigation, however, is
restricted to those planforms for which no vortex sheet appears
off the tip .  for points in the tip region, the potential is obtained
through the appropriate distribution of /modified/ sources in the
upwash region off the tip .  by transforming to a curvilinear, nonorthogonal
coordinate system coincident with the modified mach
lines described by the infinities of the potential, an integral equation
for the required source distribution in the upwash region is
derived .  without having to solve this equation, it is shown that
the potential for a point in the tip region can be obtained in terms
of an integration of known source distributions over the blade
surface only .
  the case of a twisted flat plate of particular planform is treated,
and a sample calculation is made of the pressure distribution at
selected radial positions within the noncommunicating portion
of the blade, as well as over the entire tip region .
  though this analysis is carried out explicitly for the supersonic
propeller, it could also be extended to calculate various rotary
derivatives for highspeed flight vehicles .
</TEXT>
</DOC>
