Aerodynamic Optimal Engine Integration for a Business Jet Configuration.

For a generic transport aircraft configuration with engines installed at the tail optimizations were performed with design parameters deforming the shape of fuselage tail, pylon and nacelle successively to assess the potential of each component. To perform the simulation based optimizations in an adequate time frame the Euler equations have been solved since comparisons with viscous flow calculations showed that transonic effects which were responsible for installation interference effects were predicted reasonably well. Finally the viscous drag of all optimized geometries, promising drag savings of nearly 5 drag counts from the inviscid calculations, were re-calculated solving the Reynolds-averaged Navier-Stokes (RANS) equations. While these final assessments also demonstrated drag savings, the predicted gain is smaller, which leads t