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US 5,957,662 AGranted
helicopter blade aerofoil
AssigneeAdvanced Technology Institute of Commuter-Helicopter, Ltd.
InventorsMakoto Aoki, Hiroki Nishimura, Eiichi Yamakawa
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AssigneeAdvanced Technology Institute of Commuter-Helicopter, Ltd.
InventorsMakoto Aoki, Hiroki Nishimura, Eiichi Yamakawa
Estimating the term…
In a helicopter blade aerofoil, upper and lower surfaces thereof are defined by the following coordinates, and the leading edge profile of the aerofoil is defined by the following leading edge radius and center of circle. Thus drag divergence Mach number Mdd and maximum lift coefficient Clmax can be increased and the level of noise can be reduced. ______________________________________ X/C Yup/C Ylow/C ______________________________________ 0.00000 0.00000 0.00000 0.00250 0.00781 -0.00558 0.00500 0.01131 -0.00765 0.00750 0.01423 -0.00874 0.01000 0.01660 -0.00964 0.01750 0.02224 -0.01156 0.02500 0.02658 -0.01276 0.50000 0.03585 -0.01568 0.07500 0.04128 -0.01758 0.10000 0.04480 -0.01901 0.15000 0.04893 -0.02113 0.20000 0.05095 -0.02306 0.25000 0.05181 -0.02492 0.30000 0.05200 -0.02647 0.35000 0.05179 -0.02760 0.40000 0.05129 -0.02821 0.45000 0.05038 -0.02827 0.50000 0.04888 -0.02775 0.55000 0.04673 -0.02662 0.60000 0.04393 -0.02491 0.65000 0.04037 -0.02268 0.70000 0.03592 -0.01996 0.75000 0.03052 -0.01682 0.80000 0.02430 -0.01337 0.85000 0.01751 -0.00974 0.90000 0.01046 -0.00597 0.95000 0.00407 -0.00236 1.00000 0.00207 -0.00079 ______________________________________ Leading edge radius r/C = 0.00844, Center of circle X/C = 0.00842, Y/C = 0.00064,
A helicopter blade aerofoil having coordinate values with .+-.3% errors of upper and lower surfaces on the basis of a reference aerofoil having a thickness to chord ratio of 8%, of which upper and lower surfaces are substantially defined by the following coordinates and of which leading edge profile is substantially defined by the following leading edge radius and center of a circle:
A helicopter blade aerofoil having coordinate values with .+-.3% errors of upper and lower surfaces on the basis of a reference aerofoil having a thickness to chord ratio of 5% to 11%, of which upper and lower surfaces are substantially defined by the following coordinates and of which a leading edge profile is substantially defined by the following leading edge radius and center of a circle:
Dependencies are inferred from the claim text.