초록 ▼

An airfoil member having an upper surface contoured to create lift. The lower airfoil surface has a lower forward surface portion which, in a rearward direction, curves concavely into an expanded convexly curved lower surface belly portion. This enables a primary load carrying member (e.g. a spar) t

An airfoil member having an upper surface contoured to create lift. The lower airfoil surface has a lower forward surface portion which, in a rearward direction, curves concavely into an expanded convexly curved lower surface belly portion. This enables a primary load carrying member (e.g. a spar) to be located in the belly section and have a relatively greater depth, without unnecesary sacrifice of aerodynamic performance. In another embodiment, both the upper and lower surfaces of the airfoil are contoured with the expanded belly portion.

대표청구항 ▼

An airfoil having a leading edge, a trailing edge, an upper surface, a lower surface, a chord-wise axis and a spanwise axis, said airfoil comprising at a chord-wise location on said spanwise axis: a. a substantially uniterrupted upper skin member defining said upper surface and being aerodynamically

An airfoil having a leading edge, a trailing edge, an upper surface, a lower surface, a chord-wise axis and a spanwise axis, said airfoil comprising at a chord-wise location on said spanwise axis: a. a substantially uniterrupted upper skin member defining said upper surface and being aerodynamically contoured to form a flow pattern over the upper surface to produce an upward lift; b. a substantially uniterrupted lower skin member defining said lower surface, said lower skin member comprising: 1. a first forward lower surface portion extending rearwardly from said leading edge to a first inflection point; 2. a second transitional lower surface portion extending rearwardly from said first surface portion at said first inflection point to curve concavely downwardly to a second inflection point, said second inflection point being located rearwardly from said leading edge at a distance between one-quarter to four-tenths of a chord length of said airfoil at said chord-wise location; 3. a third belly lower surface portion extending rearwardly from said second lower surface portion at said second inflection point to curve convexly to form a downwardly expanded belly section of said airfoil; 4. a fourth trailing edge lower surface portion extending from said third lower surface portion to said trailing edge; c. said lower surface portions being contoured to form a flow pattern where flow along said first and second lower surface portions is at an average lower velocity, and flow along said third lower surface portion is at a relatively higher average velocity, in a manner that relatively greater lifting force is exerted at the first and second lower surface portions, and relatively less lifting force is exerted at the third lower surface portion; d. a primary load bearing structure located primarily in the belly section of the airfoil; whereby said airfoil is aerodynamically contoured to function effectively aerodynamically, and yet provide relatively greater airfoil thickness at said belly section to enable said primary load carrying structure to have a relatively large height dimension.