FOREBODY VORTEX CONTROL FOR WING ROCK SUPPRESSION

Static and free-to-roll tests were conducted in a water tunnel and a w ind tunnel with a configuration that consisted of a highly slender for ebody and 78-deg-sweep delta wings. The mechanisms governing the wing rock of this configuration are the interactions between the forebody a nd the wing vortices. Means of suppressing wing rock by controlling th e forebody vortices using small blowing jets were explored. Steady blo wing tangentially aft from leeward nozzles near the forebody tips was found to be capable of suppressing wing rock. The wing rock motion was attenuated at low blowing rates and eliminated at high blowing rates. At high blowing rates, however, significant vortex asymmetries were a lso induced. On the other hand, alternating pulsed blowing on the left and right sides of the forebody was demonstrated to potentially be an effective means of suppressing wing rock without creating, on a time- average basis, large flow asymmetries.