Method and device for decreasing the flow resistance on wings particularly aerofoils and blades of turbomachines exposed to gas flux such as air

Claim 1

A device for use with fluid flow engines comprising: a foil member (2) with a root (5) and a tip (7), said member having a fluid flow foil cross sectional configuration with upper and lower surfaces and a chord line (11) connecting leading (4) and trailing edges; at least one blade (1, 1a) arranged on the upper surface of said foil member adjacent the leading edge thereof, said blade having a fluid flow cross sectional configuration with a chord line (10, 10a) connecting leading and trailing edges, said blade having one end (12) integrally mounted in said root (5) of said foil member (2) so that said blade extends at an angle from said leading edge (4) of said foil member to form a gap (6, 6a) between the other end (9, 9a) of said blade and the tip (7) of said foil member, said gap diverging in a direction away from said root of said foil member, said blade being formed such that the position of the chord line (10, 10a) of said blade changes with respect to the chord line (11) of said foil member between the region proximate said one end (12) of said blade and the region proximate said other end (9, 9a) of said blade, said fluid flow cross section of said blade having a greater camber proximate said one end than said other end said chord line (10, 10a) of said blade converging with the chord line (11) of said foil member toward said leading edge (4) in the region proximate to said one end (12) of said blade and diverging in the region proximate said other end (9, 9a) of said blade, said other end (9, 9a) of said blade (1, 1a) terminating coextensively with the tip (7) of said foil member (2), said blade (1, 1a) being shaped in conformity with said leading edge (4) of said foil member and said other end (9, 9a) of said blade being above said tip (7) of said foil member (2) wherein said foil member and blade are negatively swept.

Claim 2

A device for use with fluid flow engines comprising: a foil member (2) with a root (5) and a tip (7), said member having a fluid flow foil cross sectional configuration with upper and lower surfaces and a chord line (11) connecting leading (4) and trailing edges; at least one blade (1, 1a) arranged on the upper surface of said foil member adjacent the leading edge thereof, said blade having a fluid flow cross sectional configuration with a chord line (10, 10a) connecting leading and trailing edges, said blade having one end (12) integrally mounted in said root (5) of said foil member (2) so that said blade extends at an angle from said leading edge (4) of said foil member to form a gap (6, 6a) between the other end (9, 9a) of said blade and the tip (7) of said foil member, said gap diverging in a direction away from said root of said foil member, said blade being formed such that the position of the chord line (10, 10a) of said blade changes with respect to the chord line (11) of said foil member between the region proximate said one end (12) of said blade and the region proximate said other end (9, 9a) of said blade, said fluid flow cross section of said blade having a greater camber proximate said one end than said other end said chord line (10, 10a) of said blade converging with the chord line (11) of said foil member toward said leading edge (4) in the region proximate to said one end (12) of said blade and diverging in the region proximate said other end (9, 9a) of said blade, said other end (9, 9a) of said blade (1, 1a) terminating coextensively with the tip (7) of said foil member (2), said blade (1, 1a) being shaped in conformity with said leading edge (4) of said foil member and said other end (9, 9a) of said blade being above said tip (7) of said foil member (2) wherein said foil member and blade are negatively swept.