Treffer: Validated Medium-Fidelity Aerodynamic Optimization of a Box Wing Aircraft

This study provides a comprehensive analysis with regards to a developed parametric optimization approach to increase the aerodynamic performance of a box-wing aircraft configuration. Aerodynamic analysis was incorporated through the ncompressible Vortex Lattice Method in XFLR5, alongside a secondary validation aerodynamic analysis in ANSYS Fluent as the high-fidelity tool with applied viscous and boundary layer effects. A comparison of the resulting planform when using NACA 4412 or 2412 was conducted to observe the effects of varying camber in the optimization process. Initial aerodynamic analysis in XFLR5 at subsonic conditions of 50 m/s and over a range of angles of attack was completed to observe the lift and drag characteristics. A convergence study modeling Richardsons Extrapolation (RE) as a variation of the Grid Convergence Index method verified the data from the selected panel densities of 792, 1440, and 2394 to be used for optimization. The optimization approach was developed in Python and utilized the Sequential Least Squares Quadratic Programming algorithm from the SciPy library. Selected design variables including the wingspan, root and tip chord, wing sweep, and wing height. These were constrained within a set of reasonable bounds and used as the basis of an aerodynamic optimization which sought to maximize the lift-to-drag ratio while limiting the drag coefficient. A second analysis in Fluent validated the optimized design parameters and their aerodynamic values in XFLR5. The results of this study demonstrated significant improvements in aerodynamic performance for both the NACA 4412 and NACA 2412 box wing configurations, highlighting the effectiveness of the developed approach and analysis of multi-fidelity optimization. For the NACA 4412 configuration, the optimized lift coefficient at 0- and 6-degrees angle of attack experienced an 8.52% and 9.06% increase. Given the same optimization approach, the NACA 2412 experienced a lower increase in lift coefficients. At 0- and 6-degrees angle of attack, ...