Investigating the accuracy of different fidelity numerical methods for modelling the aerodynamics of a box-wing aircraft

摘要

This paper deals with the aerodynamics of a box-wing (a type of closed-wing) aircraft. As demand for long-endurance long-range unmanned aircraft is still rising rapidly, closed-wing designs could provide a cheaper, smaller and more efficient solution. Current literature on the topic mostly omits the deeper aerodynamic analysis, and instead opts for low-fidelity methods. Research of this unconventional wing shape is important to design, build and maintain aircraft for higher range, endurance and lower price. Computational Fluid Dynamics (CFD) analysis with high resolution methods is carried out on a small test aircraft. The investigation starts from Reynolds-Averaged Navier–Stokes (RANS) simulations with Shear Stress Transport (SST) turbulence model, and continued with higher accuracy Large Eddy Simulation (LES) and Detached Eddy Simulation (DES) models. Adaptive meshing is used for increased accuracy and performance. Numerical results are then compared to wind tunnel tests. The lift coefficients calculated and measured were particularly well matched. Pressure and shear stress distributions around the wings produced very similar profiles with every model.udKeywords: RANS, DES, LES, box-wing, nonplanar wing, UAV