Effects of a Movable Tip Strake on Wake Vortex Structure

Abstract

The impact of a tip-mounted strake, set at different deflection angles relative to the main-wing chord plane on the near-field wake vortex structure, and the associated lift-induced drag were investigated experimentally at Re = 191, 000. Force-balance aerodynamic forces were also obtained to supplement the wake vortex measurements. The results show that in addition to its substantial influence on the aerodynamic performance, the presence of the strake also led to an earlier completion of the rolling up of the tip vortex, compared with the baseline wing. The tip vortex had a reduced peak tangential velocity and core axial velocity but an increased core radius, compared with the baseline wing. These vortex core flow quantities increased with increasing strake angle δ. The core and total circulation increased above and remained below the baseline-wing value for δ > 5 deg and δ 5 deg.