Geometry optimization studies on nonplanar wingtip devices for typical transport aircraft

Abstract

Abstract Wings are the main lift generating sources for an aerospace system. Wing design is a complex process that involves selection of many aerofoil design parameters, wing design requirements and considerations. The main focus in this study is to validate nonplanar wingtip design methodologies and make a numerical estimation and comparison of aerodynamic characteristics of non planar wing tip devices and the associated induced drag. Naturally the high pressure on the bottom surface of the wing causes streamlines from underneath the wing to wrap around the tip to the top, thereby equalizing the pressure difference at the tip. This creates the rotating flow commonly known as a wing tip vortex. The current study investigates and assesses the possibility of retrofitting a non planar wing tip device for the rectangular tapered wing configuration without adding any additional weight to the main wing structure. There are basically three case studies. The first one is a validation of predicted experimental data against numerical simulation using FLUENT® tool for classical NACA 23015 aerofoil. The second one involves taking into consideration possible mounting location of the nonplanar wingtip device on the main wing for smooth operation and gradual lift generation process. A third case study is comparison of ‘wing alone experimental data’ against ‘wing with nonplanar winglet’data computed using FLUENT® in three dimensional space. Additionally estimation of numerical optimum load distribution is done for one of the optimum nonplanar winglet geometry using MATLAB tool. Finally comparison of MATLAB results with experimental loading is done for clarity.