| 摘要 |
An improved nacelle is provided for housing an aircraft engine and reducing aerodynamic drag during aircraft operation. In one embodiment, the nacelle houses a gas turbine engine and forms the fan cowl 24 of a turbofan engine having a fan 16 and comprises a leading edge and a trailing edge, having a reference chord extending therebetween, and an outer surface which is continuous from the leading edge to the trailing edge. The outer surface includes a forward portion, an intermediate portion and an aft portion and has a profile defined by a varying thickness measured perpendicularly from the chord to the outer surface. The profile has a maximum thickness at the intersection of the forward and intermediate portions, which intersection is located greater than about 36% and probably at 56% of the chord from the leading edge, and is effective for increasing laminar flow over the nacelle for reducing aerodynamic drag. The flow is turbulent aft of the maximum thickness. <IMAGE> |
