2D and 3D gust response using a prescribed velocity method in viscous flows

Results are presented for the interaction between a wide body aircraft and a gust using the split velocity method, which has been extended to viscous flows. The method is first demonstrated for two dimensions on a NACA 0012 aerofoil before being extended to the 3D case. In both instances a series of 1-Cosine gusts were used to compare solutions between the split velocity method and, another prescribed velocity method, the field velocity method. The field velocity method is shown to be a simplification of the split velocity method, with the latter requiring extra source terms that account for the interaction of the aerofoil on the gust. It was found that the differences were small for longer wavelength gusts but at shorter wavelengths the gradients become larger and the split velocity method produces more accurate results.