On the Control of a Leading-Edge Vortex & its Liftoff on a Cranked, Swept Back Wing

Abstract

This study examines flow over a cranked {\lambda}-wing model with a sweep of {\Lambda}=60{\deg} of the inboard leading edge (LE) that changed to {\Lambda}=30{\deg} outboard of the crank. The study focuses on the liftoff of the inboard Leading-Edge Vortex (LEV) and its influence over the flow on the outer wing. Stereoscopic Particle Image Velocimetry (SPIV) indicates that the flow is largely separated and dominated by strong outboard spanwise flow at {\alpha}=14{\deg}. The separation is mitigated by a small, steady supersonic jet that interacted with the lifted vortex and changed the pitch characteristic of the entire model. The use of Proper Orthogonal Decomposition (POD) revealed the unsteadiness of the separated structures that may cause wing flutter.