<DOC>
<DOCNO>
1270
</DOCNO>
<TITLE>
supersonic inlet dynamics .
</TITLE>
<AUTHOR>
fraiser,h.r.
</AUTHOR>
<BIBLIO>
j. ae. scs. 1960, 429.
</BIBLIO>
<TEXT>
  an approximation of the differential equation for compressible
duct flow is presented .  the equation is linear and of the second
order .  the duct transfer function and response characteristics
are obtained by applying small-perturbation theory to the differential
equation .  the resulting equations describe duct
natural frequency as a function of duct areas and volumes, and
damping ratio as a function of the slope of the steady-state mass
flow, pressure-recovery curve .
  the calcualted response agrees, to a first approximation, with
measured response as obtained from tests of a fixed-geometry,
sugar-scoop inlet model with hypass for matching airflows .  testing
was done in the 10 x 10 and 8 x 6 ft. supersonic tunnels
at nasa lewis flight propulsion laboratory .  further agreement
was obtained during flight tests of the f8u-3 airplane .
</TEXT>
</DOC>
