Wingtip Vortices Characterization with Perspective Upright Correction

Accurately predicting wingtip vortices is critical for future development of wake vortex surfing operations. Experimental methods such as wind tunnel tests are the most common and reliable approaches to visualize and characterize the trailing vortices, especially with the advancing Laser Doppler Anemometry (LDA) and Particle Image Velocimetry (PIV) techniques. However, the implementation of LDA or PIV with a single camera to get an upright and perpendicular view angle to the targeted plane can be expensive and time-consuming. To overcome the limitation, this paper proposes a novel methodology for perspective upright correction that allows adjustment of the slanted plane during post-processing. This method can be applied to any visualization effort involving a laser sheet and camera. In this paper the method is demonstrated for the characterization of wingtip vortices for NACA4412 with and without winglets, and the results obtained from the proposed methodology can be used for validation of numerical models to capture the vortex evolution downstream of the wing tips.