SECTIONAL SHAPE ALONG FLUID FLOW OF AEROFOIL FOR OBTAINING LIFT FROM FLUID, VANE OF PROPELLER OR SCREW FOR OBTAINING THRUST FROM FLUID AND VANE OF FAN FOR MOVING FLUID, ETC.

摘要

PURPOSE:To obtain lift or thrust with high efficiency, by forming a sectional shape of various vanes along a fluid flow into a parabolic curve wherein a front surface of the vane against the fluid flow has a large curvature at its front side and a chord is directed to the inside, while a back surface has a small curvature at its front side. CONSTITUTION:A sectional shape of the above-captioned vanes along a fluid flow (aerofoil section) is formed into a parabolic curve such that a front surface 1 against the fluid flow has a large curvature at its front side and a chord is directed to the inside, while a back surface 2 has a small curvature at its front side and a chord is directed to the inside. A front end of the back surface 2 and a rear end of the front surface 1 are so arranged as to be tangential with the fluid flow, so that the fluid flow against the front surface 1 may be rapidly changed downwardly at the large curvature front portion. Then, a pressure wave of the fluid is sufficiently diffused at the small curvature portion so as not to be stayed at the rear end.