ABSTRACT
A high static pressure at the inlet face and minimal total pressure loss at the intake
entry are required for an efficient operation of the spiked supersonic jet engines. The
turning (Forebody) angles are optimized for a maximum total pressure recovery at the
intake entry for the design Mach number condition, so that the compression shocks fall
on the cowl lip. Non zero incidence angle changes the effective deflection angle up and
down the spike, so the combining effect of incidence and forebody angles is essential
for the intake performance. The present analysis investigates the pressure distribution
at the compressor face at different forebody-Incident combinations at different
supersonic fly speeds ranging from 1.8 to 2.2 Mach. The numerical analysis is carried
out under 2-D, steady and viscous flow assumptions. The external flow, which consists
of the set of waves, is solved analytically. CFD analysis using Control Volume
Formulation technique is applied to analyze the internal flow. In house program is built
to solve the governing sets of equations by using SIMPLE algorithm. The analyses are
carried out at incidence angles ranging from 0o to 10o and forebody angles ranging from
6o to 25o. The procedure has been verified by comparing with previous experimental
results. The results obtained have generally shown, that the pressure recovery
increases by the increasing of the wedge angle and decreases by increasing of
incidence angle. In some operating conditions, the combination of the three factors,
Mach no., the incidence, and the forebody angle results in a complicated mechanism
due to the presence of compression and expansion waves in the external part of the
intake simultaneously.