Performance and noise trade-offs on a civil airliner with over-the-wing engines

Community noise has become a major consideration in the design of new aircraft. The noise generated by the engines has decreased over the generations to the extent that a whole-airframe approach is required now to achieve further significant reductions. One option is to install the engines over the wings so the airframe reflects the fan noise away from on-the-ground observers. However, in addition to good noise shielding performance, the position of the engine also has to satisfy aerodynamic effciency criteria. We investigate the sensitivity of aerodynamic and acoustic performance metrics with respect to the positioning of the engine relative to the wing. More specifically, we trade drag computed via Reynolds-Averaged Navier Stokes simulations versus noise shielding performance, obtained experimentally through scale model tests conducted in an anechoic chamber. Surrogate models of both metrics are constructed, enabling their Pareto analysis on the specific case of a modified DLR F6 airframe geometry.