Abstract: Visualization of aerodynamic effects on a three-dimensional
double-delta wing aircraft model was conducted using an optical pressure
measurement system, based on the Pressure Sensitive Paint (PSP) technique, and
in addition a laser-light sheet method. The combination of PSP technology with
the laser-light sheet method, provides a good understanding of the flow around
the wind tunnel model. In recent years, this novel PSP-technology has attracted
considerable attention in the aerospace community. The PSP technique can be
used to realize absolute pressure measurements on a surface of a model and in
addition to evaluate quantitative aerodynamic flow phenomena using a scientific
grade camera and image processing techniques. The PSP system was tested in the
Transonic Wind Tunnel of the German Aerospace Center in Göttingen (TWG)
under real flow conditions. Instantaneous pressure distributions are recorded
in almost real-time so that the recognition and analysis of the vortex dynamics
on the model surface is possible. Even the vortex breakdown process, as well as
the fine structured Kelvin-Helmholtz instabilities and secondary vortex
structures, can be detected by this measurement technique.