In order to investigate the effects of vortex control by delfecting flaps on
the improvement of the aerodynamic performance of highly swept wings at large
incidence, comparison of experimental and numerical studies were conducted 
for a 74 deg. delta wing equipped with an apex flap and a leading-edge flap.
In the experimental study, flow visualization and force measurement were
employed, and in the numerical study the pseudocompressibility method was 
used to solve the 3-D incompressible Navier-Stokes equations. The flow
visualization and the numerical simulation show that two vortex systems 
generated on the apex flap and the leading-edge flap interact in the form of
mergence, and the downward deflection of the apex flap enhances the strength 
of and delays the breakdown of the primary vortex at large incidence.
The comparison of the aerodynamic characteristics illustrates that there are 
advantageous effects by deflecting flaps donward on the vortex control.