Nato avt-239 task group: On the use of active flow control (afc) on tailless aircraft models to affect their trim and control

Tests were carried out on a selected number of tailless aircraft planforms and swept-wings in order to understand their non-linear pitch characteristics. Although our task was to overcome the pitch– break on the SACCON (Stability And Control CONfiguration) model, we turned our attention to the universality of this problem and the means to control it. A small number of sweeping jet actuators were used for this purpose and they were most effective when located downstream of the local mid-chord of the wing prior to stall. It was realized that the location of the actuator, its orientation and the level of its momentum output are important parameters affecting the flow and the integral wing characteristics. Therefore, one may change these features by deploying either control surfaces, AFC or a combination of both, noting that there is a strong coupling among all the variables involved. CFD provided guidance to the location and orientation of the actuation and affirmed some of the observations made during the tests.