An Experimental Investigation Of Wingtip Vortices Generated By A Reverse Delta Wing Of Different Wing Configurations

Download or read book An Experimental Investigation of Wingtip Vortices Generated by a Reverse Delta Wing of Different Wing Configurations written by Mengyizhe He and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "The reverse delta wing (RDW) planform is uniquely seen on the Lippisch-type wing-in-ground effect vehicles that have emerged as a new and sustainable mode of commercial sea travel in the last decade, yet public archives of RDWs are rarely seen and relevant academic studies are scarce. This study investigates wingtip vortices generated by different RDW configurations outside ground effect (GE) as to expand knowledge about RDWs and to establish potential benchmark data for future studies in GE. Flow measurements of 16" in chord 65 ̊-sweep RDW models were obtained using a seven-hole pressure probe at low subsonic speeds and a Reynolds number of 3.3x10^5. Major attention was paid to the streamwise evolution and characteristics of the tip vortices at the angle of attack of 16 ̊. The various wing models were configured with, separately and jointly, trailing-apex cropping, anhedral and winglets. Gurney flaplike strips were also examined as a lift augmentation and passive flow control device. In addition, the lift and drag forces of each configuration were measured via a force balance to supplement the flow-field data. The cropping had a minimal impact on the RDW vortices and aerodynamic forces while the anhedral engendered faster-rotating vortices and minimized lift-induced drag. The side-edge strips enhanced the vortex strength and wing lift, but also drag. The winglets generated a co-rotating vortex pair but kept the vortex strength mostly intact. Lift based on the total vortex circulation underestimated the experimental values by 1.5-11.3%, suggesting that the RDW vortex strength can represent majority of the actual lift. Lastly, induced drag computed using the vorticity flow field constituted 17.6-27.5% of the total drag." --