Software Testing: VSPAERO

Abstract

Purpose – Test the aerodynamic analysis code VSPAERO, which is part of OpenVSP from NASA. Apply VSPAERO to calculate the lift curve slope and the span efficiency factor of straight wings (for various aspect and taper ratios) as well as the induced drag of box wings (for various h/b-ratios) relative to their reference wing. --- Methodology – VSPAERO results are compared with results from analytical equations, wind tunnel measurements, and results produced with other aerodynamic codes. --- Findings – VSPAERO offers correct and reliable results, if the simulation is set up with care. The user must always keep an eye on model discretization and refinement, flow conditions, and number of iterations. The Vortex Lattice Method (VLM) and the panel method are best used for different purposes. The VLM shows shorter simulation time and produces reliable results. The panel method is more complicated to use. Numerical results are also good. In addition, the panel method can be used better to visualize flow phenomena. Hoerner's simple approach to induced drag estimation can be used to approximate results of the VLM and the panel method, if a simple correction factor is applied. --- Research Limitations – Most of the tests of VSPAERO have been done with a simple wing geometry, as such much simpler than a full aircraft geometry. --- Practical Implications – VSPAERO can be used with relative ease. It can also be used to show flow phenomena on full aircraft geometry. --- Originality – Repeating simple calculations done many times before does not sound original, but doing this with the relatively new software VSPAERO offering the VLM as well as the panel method seems to be original after all.