Over-wing integration of ultra-high bypass ratio engines: A coupled wing redesign and engine position study

A Review of Novel and Non-Conventional Propulsion Integrations for Next-Generation Aircraft

“…In that work [85], advanced simulation techniques based on CFD RANS solvers are applied to investigate and discuss three main aspects: (i) the need to reshape the wing design downstream of the propulsive unit integration, as the presence of an overwing assembly introduces significant losses of lift; (ii) the sensitivity of drag to the turbofan positioning, and the search for an optimal installation; and (iii) the comparison in terms of drag between the optimal overwing assembly and a canonical underwing reference layout. Regarding the first point, the study in [85] presents reshaping techniques useful for the recovery of the wing's lifting capability. In particular, the related discussion points out that a traditional approach in which the nacelle, pylon and wing are designed individually and then assembled, can no longer be applied in the case of overwing assembly, since the errors on the aerodynamic forces introduced by the interference would be non-negligible.…”

“…A specific discussion on an overwing pylon design process is reported in [84], where some design variables and constraints related to the overwing pylon design are generally addressed, providing a frame for further development. The problem of the strict coupling in the design of the wing and the propulsive unit for an overwing assembly of a UHBR turbofan is discussed in more detail in [85]. In that work [85], advanced simulation techniques based on CFD RANS solvers are applied to investigate and discuss three main aspects: (i) the need to reshape the wing design downstream of the propulsive unit integration, as the presence of an overwing assembly introduces significant losses of lift; (ii) the sensitivity of drag to the turbofan positioning, The problem of the strict coupling in the design of the wing and the propulsive unit for an overwing assembly of a UHBR turbofan is discussed in more detail in [85].…”

“…The problem of the strict coupling in the design of the wing and the propulsive unit for an overwing assembly of a UHBR turbofan is discussed in more detail in [85]. In that work [85], advanced simulation techniques based on CFD RANS solvers are applied to investigate and discuss three main aspects: (i) the need to reshape the wing design downstream of the propulsive unit integration, as the presence of an overwing assembly introduces significant losses of lift; (ii) the sensitivity of drag to the turbofan positioning, The problem of the strict coupling in the design of the wing and the propulsive unit for an overwing assembly of a UHBR turbofan is discussed in more detail in [85]. In that work [85], advanced simulation techniques based on CFD RANS solvers are applied to investigate and discuss three main aspects: (i) the need to reshape the wing design downstream of the propulsive unit integration, as the presence of an overwing assembly introduces significant losses of lift; (ii) the sensitivity of drag to the turbofan positioning, and the search for an optimal installation; and (iii) the comparison in terms of drag between the optimal overwing assembly and a canonical underwing reference layout.…”

“…Concerning the drag sensitivity to engine positioning, contrasting trends are observed between wing and nacelle, as already noted for underwing installations. However, the authors of [85] point out that interference effects may be larger in the overwing case. Engine positioning is a key factor in overall aircraft design processes, and incorrect positioning can introduce significant alterations to the optimum aerodynamic flow (see the Figure 12, adapted from [85]) resulting in increased drag.…”

“…However, the authors of [85] point out that interference effects may be larger in the overwing case. Engine positioning is a key factor in overall aircraft design processes, and incorrect positioning can introduce significant alterations to the optimum aerodynamic flow (see the Figure 12, adapted from [85]) resulting in increased drag. positioning can introduce significant alterations to the optimum aerodynamic flow (see the Figure 12, adapted from [85]) resulting in increased drag.…”