Forebody vortex control for wing rock suppression

Abstract

Static and free-to-roll tests were conducted in a water tunnel and a wind tunnel with a configuration that consisted of a highly slender forebody and 78-deg-sweep delta wings. The mechanisms governing the wing rock of this configuration are the interactions between the forebody and the wing vortices. Means of suppressing wing rock by controlling the forebody vortices using small blowing jets were explored. Steady blowing 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 also 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.