Experimental analyses of droop, wingtips and fences on a BWB model

This work performs wind-tunnel tests to analyze the aerodynamics of wingtip devices and fences in a blended wing body aircraft (BWB). The Green aircraft concept has the BWB as a promising solution which optimally combines low-noise, fuel efficiency and consequently low-emission. This innovative approach has been consistently investigated by the Aircraft Laboratory of the São Carlos Engineering School - University of São Paulo. In previous developments, this laboratory showed the presence of cross flow on the external part of the body and an stronger vortex in the middle of the model. To avoid this undesirable effect, the first prototype has been improved by the addition of a droop and three fences. Additionally winglets and C-wings were considered in this research. Results show that wingtip devices improved the aerodynamic efficiency by the generation of an aerodynamic resultant force which has a component in the direction of the flight reducing the total drag. On the other hand, the fences showed improved efficiency at higher angles of attack.