초록 ▼

A rotary wing blade of limited taper ratio, comprising in succession along a reference radius: an inner zone; a forward-swept zone; and a back-swept zone. In addition, the beginning of the forward-swept zone lies in the range 0.47 to 0.65 times the reference radius R of the rotary wing. Furthermore

A rotary wing blade of limited taper ratio, comprising in succession along a reference radius: an inner zone; a forward-swept zone; and a back-swept zone. In addition, the beginning of the forward-swept zone lies in the range 0.47 to 0.65 times the reference radius R of the rotary wing. Furthermore, the leading edge of the blade at the reference radius presents an angle γ lying in the range-40�� and-65�� relative to the general axis of the blade.

대표청구항 ▼

What is claimed is: 1. A blade for a rotary wing which comprises in succession along a reference radius R: an inner zone; a forward-swept zone; and a back-swept zone; wherein the beginning of said forward-swept zone lies in the range 0.47 to 0.65 times said reference radius R, and wherein the leadi

What is claimed is: 1. A blade for a rotary wing which comprises in succession along a reference radius R: an inner zone; a forward-swept zone; and a back-swept zone; wherein the beginning of said forward-swept zone lies in the range 0.47 to 0.65 times said reference radius R, and wherein the leading edge of said blade at said reference radius R presents an angle γ lying in the range-40�� to-60�� relative to a general axis of said blade, wherein a taper ratio of said backswept zone lies in the range 1 to 2. 2. A blade according to claim 1, wherein the beginning of said back-swept zone lies in the range 0.75 to 0.90 times said reference radius R. 3. A blade according to claim 1, wherein said forwards-swept zone presents a sweep angle lying in the range 50�� to 10��. 4. A blade according to claim 1, wherein said back-swept zone presents a sweep angle lying in the range-15�� to-30��. 5. A blade according to claim 1, wherein said back-swept zone presents a chord that is constant and equal to the chord of the outermost section of said forward-swept zone. 6. A blade according to claim 1, further comprising an outer zone following said back-swept zone, said outermost zone presenting a taper ratio. 7. A blade according to claim 6, wherein the beginning of said outer zone lies in the range 0.92 to 0.97 times said reference radius R. 8. A blade according to claim 6, including at least one section presenting a thickness profile lying in the range 6% to 8%, said section being included in said outer zone. 9. A blade according to claim 1, including a dihedral-forming slope M at its outer tip. 10. A blade according to claim 9, wherein the angle of inclination 5 of said slope at said reference radius lies in the range 100 to 200. 11. A blade according to claim 1, wherein the beginning of said inner zone lies in the range 0.15 to 0.30 times said reference radius R. 12. A blade according to claim 1, wherein said reference radius lies in the range 5.0 m to 10.0 m. 13. A blade according to claim 1, including at least one segment having a thickness profile lying in the range 8% to 10%, said segment being situated at more than 75% of said reference radius R. 14. A blade according to claim 13, wherein said segment includes at least one section of thickness equal to 9%. 15. A blade according to claim 1, wherein said inner zone presents a chord that is constant. 16. A blade according to claim 15, wherein the chord of said inner zone lies in the range L to 1.1 times L, where L is given by: L(r) being the relationship defining how the chord varies along the span, RO being the radius at the beginning of the profiled portion, and R being the reference radius. 17. A blade for a rotary wing which comprises in succession along a reference radius R: an inner zone; a forward-swept zone; and a back-swept zone; the beginning of said forward-swept zone lying in the range 0.47 to 0.65 times said reference radius R, wherein the leading edge of said blade at said reference radius R presents an angle γ lying in the range-40�� to-60�� relative to a general axis of said blade and wherein said back-swept zone presents a chord that is constant and equal to the chord of the outermost section of said forward-swept zone. 18. A blade for a rotary wing which comprises in succession along a reference radius R: an inner zone; a forward-swept zone; and a back-swept zone; the beginning of said forward-swept zone lying in the range 0.47 to 0.65 times said reference radius R, wherein the leading edge of said blade at said reference radius R presents an angle γ lying in the range-40�� to-60�� relative to a general axis of said blade and wherein the chord of said inner zone lies in the range L to 1.1 times L, where L is given by: L(r) being the relationship defining how the chord varies along the span, R0 being the radius at the beginning of the profiled portion, and R being the reference radius. 19. A blade for a rotary wing which comprises in succession along a reference radius R: an inner zone; a forward-swept zone; and a back-swept zone; wherein the beginning of said forward-swept zone lies in the range 0.47 to 0.65 times said reference radius R, and wherein the leading edge of said blade at said reference radius R presents an angle γ lying in the range-40�� to '60�� relative to a general axis of said blade, wherein a taper ratio of said backswept zone lies in the range 1 to 2, and wherein said forwardswept zone presents a chord that is constant. 20. A blade according to claim 19, wherein said chord of said forward-swept zone is equal to the chord of said inner zone.