<DOC>
<DOCNO>
198
</DOCNO>
<TITLE>
investigation of a systematic group of naca 1 - series
cowlings with and without spinners .
</TITLE>
<AUTHOR>
nichols,m.r. and keith,a.l.
</AUTHOR>
<BIBLIO>
naca r950, 1949.
</BIBLIO>
<TEXT>
  an investigation has been conducted in the langley propellerresearch
tunnel to study cowling-spinner combinations based
on the naca 1-series nose inlets and to obtain systematic
design data for one family of approximately ellipsoidal spinners .
in the main part of the investigation, 11 of the related spinners
were tested in various combinations with 9 naca open-nose
cowlings, which were also tested without spinners .  the effects
of location and shape of the spinner, shape of the inner surface
of the cowling lip, and operation of a propeller having approximately
oval shanks were investigated briefly .  in addition, a
study was conducted to determine the correct procedure for
extrapolating design conditions determined from the low-speed
test data to the design conditions at the actual flight mach
number .
  the design conditions for the naca 1-series cowlings and
cowling-spinner combinations are presented in the form of
charts from which, for wide ranges of spinner proportions and
rates of internal flow, cowlings with near-maximum pressure
recovery can be selected for critical mach numbers ranging from
spinners and the effects of the spinners and the propeller on
the cowling design conditions are presented separately to
provide initial quantitative data for use in a general design
procedure through which naca 1-series cowlings can be
selected for use with spinners of other shapes .  by use of this
general design procedure, correlation curves established from
the test data, and derived compressible-flow equations relating
the inlet-velocity ratio to the surface pressures on the cowling
and spinner, naca 1-series cowlings and cowling-spinner
combinations can be designed for critical mach numbers as
high as 0.90 .
</TEXT>
</DOC>
