Influence of a Wing Tip Device Geometric Parameters in the Performance of a Wide-Body Model

Abstract

This paper presents the evaluation through Computational Fluid Dynamics (CFD) simulations of the performance of a wingtip device and its optimization using the Response Surface Methodology. First, an appropriate base methodology in the geometric modeling, meshing and CFD simulation processes was proposed and implemented. The base geometry evaluated was adopted from the NASA's high-speed Common Research Model (CRM). Several unstructured meshes were generated for the convergence analysis and case development of simulation models. The simulations were performed in ANSYS Fluent R23.1 and using the SST k-w RANS model. Lift, drag and pitching moment coefficients were evaluated at an angle of attack of 2.75° and a Mach number of 0.85. Numerical results of the convergence analysis and validation of base results indicated that a mesh between 20 and 25 million elements resulted as the proper size to evaluate forces and aerodynamic performance of the model and allowed the correct prediction and development of the flow and turbulence variables. Finally, an optimization of a wing tip device was performed by varying its geometric design parameters: angle of inclination, sweep angle and intensity of transition curvature. By applying the Response Surface methodology, the total drag effect was fitted to a polynomial model that combines the effects of the geometric parameters of the wingtip device. The best winglet model was obtained, which allowed a total drag of 12\% with respect to the CRM base model without wingtip device. In addition, it allowed us to obtain a better response with less intense and smoother visual of tip vortex generation.