Automated Redesign of the NASA P8 Hypersonic Inlet Using Numerical Optimization

Vijay Shukla, Andrew Gelsey, Mark Schwabacher, Donald Smith,
 and Doyle D. Knight

November 1995

The NASA P8 hypersonic inlet has been redesigned using an automated
methodology incorporating a 3-D Reynolds-averaged Navier-Stokes code,
a gradient-based optimizer and artificial intelligence methods.

The objective of the redesign is to cancel the cowl shock and the
additional cowl-generated compression at the centerbody by appropriate
contouring of the centerbody boundary.  The original P8 inlet,
designed in the early 1970s, was intended to achieve this same
objective, but detailed experimental measurements indicated that a
substantial reflected shock system was present.

We have obtained several different redesigns which achieve approximate
cancelation of the cowl shock and additional cowl-generated
compression.  The choice of the objective function, which is used to
drive the optimization, has a significant impact on the final design.
Several different formulations for the objective function have been
employed, and improvements of 60% to 80% have been achieved.