Helicopter blade aerofoil
AssigneeAdvanced Technology Institute of Commuter-Helicopter, Ltd.
InventorsMakoto Aoki, Hiroki Nishimura, Eiichi Yamakawa
Life of this patent
Estimating the term…
Abstract
The coordinates defining the upper surface, lower surface, leading edge configuration and center of circle for a helicopter blade airfoil are given to increase maximum lift coefficient and lift-to-drag ratio, and to reduce noise level.
Claims4
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 10%, 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:
- ______________________________________ X/C Yup/C Ylow/C ______________________________________ 0.00000 0.00000 0.00000 0.00100 0.00604 -0.00438 0.00250 0.00953 -0.00691 0.00500 0.01349 -0.00900 0.00750 0.01676 -0.01027 0.01000 0.01962 -0.01120 0.01750 0.02660 -0.01308 0.02500 0.03207 -0.01447 0.05000 0.04468 -0.01740 0.07500 0.05284 -0.01938 0.10000 0.05830 -0.02086 0.15000 0.06430 -0.02358 0.20006 0.06676 -0.02631 0.25000 0.06762 -0.02888 0.30000 0.06762 -0.03101 0.35000 0.06715 -0.03256 0.40000 0.06624 -0.03350 0.45000 0.06456 -0.03400 0.50000 0.06197 -0.03392 0.55000 0.05849 -0.03319 0.60000 0.05415 -0.03179 0.65000 0.04895 -0.02966 0.70000 0.04287 -0.02670 0.75000 0.03598 -0.02291 0.80000 0.02846 -0.01841 0.85000 0.02057 -0.01399 0.90000 0.01259 -0.00802 0.95000 0.00527 -0.00299 1.00000 0.00231 -0.00094 ______________________________________
- Leading edge radius r/C=0.0159,
- Center of circle X/C=0.0159, Y/C=0.0005,
- where X is a distance from the leading edge to a trailing edge along a chord line, C is a length of the aerofoil in the chord direction, Yup is a distance from the chord line to the upper surface, Ylow is a distance from the chord line to the lower surface, and r is the leading edge radius.
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 10%, 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:
- ______________________________________ X/C Yup/C Ylow/C ______________________________________ 0.00000 0.00000 0.00000 0.00100 0.00514 -0.00575 0.00250 0.00862 -0.00786 0.00500 0.01274 -0.01020 0.00750 0.01615 -0.01135 0.01000 0.01913 -0.01218 0.01750 0.02639 -0.01374 0.02500 0.03208 -0.01484 0.05000 0.04525 -0.01716 0.07500 0.05382 -0.01862 0.10000 0.05954 -0.01980 0.15000 0.06576 -0.02207 0.20000 0.06822 -0.02470 0.25000 0.06903 -0.02729 0.30000 0.06895 -0.02948 0.35000 0.06841 -0.03110 0.40000 0.06744 -0.03211 0.45000 0.06568 -0.03270 0.50000 0.06301 -0.03272 0.55000 0.05943 -0.03211 0.60000 0.05498 -0.03083 0.65000 0.04968 -0.02883 0.70000 0.04349 -0.02601 0.75000 0.03649 -0.02235 0.80000 0.02886 -0.01799 0.85000 0.02087 -0.01309 0.90000 0.01279 -0.00784 0.95000 0.00538 -0.00291 1.00000 0.00236 -0.00095 ______________________________________
- Leading edge radius r/C=0.0162
- Center of circle X/C=0.0162, Y/C=-0.0006,
- where X is a distance from the leading edge to a trailing edge along a chord line, C is a length of the aerofoil in the chord direction, Yup is a distance from the chord line to the upper surface, Ylow is a distance from the chord line to the lower surface, and r is the leading edge radius.
Dependencies are inferred from the claim text.