초록 ▼

The invention relates to improvements to air propellers in so far as the profile of their blades is concerned. The law of evolution of the curvatures of the extrados 2 is the following: the curvature, maximum at the leading edge A, increases first of all rapidly to reach a value of about 4 at the po

The invention relates to improvements to air propellers in so far as the profile of their blades is concerned. The law of evolution of the curvatures of the extrados 2 is the following: the curvature, maximum at the leading edge A, increases first of all rapidly to reach a value of about 4 at the point B at about 4% of the length of the chord, and then decreases regularly to reach a substantially zero value at the trailing edge F. The law of evolution of the curvatures of intrados 3 is the following: the curvature, maximum at the leading edge A, decreases first of all rapidly to reach a value of about 8 at a point D at about 3.5% of the length of the chord, then decreases less rapidly to reach a zero value at a point E situated between 10% and 60% of the length of the chord, decreases further to a slightly negative value and then remains practically constant as far as the trailing edge F.

대표청구항 ▼

A propeller blade having a profile whose relative thickness is comprised between 3% and 25%, whose extrados has a convex shape between the leading edge and the trailing edge and whose intrados has a shape first of all convex on leaving the leading edge then concave on arriving at the trailing edge,

A propeller blade having a profile whose relative thickness is comprised between 3% and 25%, whose extrados has a convex shape between the leading edge and the trailing edge and whose intrados has a shape first of all convex on leaving the leading edge then concave on arriving at the trailing edge, characterized by the following values of the curvatures on the extrados: the curvature, maximum at the leading edge, decreases first of all rapidly to reach a value of about 4 at about 4% of the length of the chord and then decreases regularly to reach a substantially zero value at the trailing edge; and by the following values of the curvatures on the intrados the curvature, maximum at the leading edge, decreases first of all rapidly to reach a value of about 8 to about 3.5% of the length of the chord, then decreases less rapidly to reach a zero value at a point situated between 10% and 60% of the length of the chord, further decreases to a slightly negative value, and then remains practically constant as far as the trailing edge.