Turbomachine with coaxial propellers
The invention relates to a nubomachine with a longitudinal axis, comprising two, respectively upstream ( 122 ) and downstream, coaxial outer propellers ( 122 ), characterised in that at least some of the blades ( 148 ) of the upstream propeller ( 122 ) comprise at least one internal air circulation chimney ( 150 ) that communicates with air-bleeding openings ( 152 ) in tire boundary layers of the blades ( 148 ), and communicates with air outflow openings ( 158 ) on the radially outer end thereof, the air-bleeding openings ( 152 ) leading to opening inlets ( 152 a ) on tire passive surfaces ( 156 ) of the blades ( 148 ), the inlets ( 152 a ) of the air-bleeding openings being radially arranged in an area (H 1 ) contained between 10% and 45% of the radial dimension (H 2 ) of the blades ( 148 ), measured above turd from the radial height of the blades for which the tangent of the leading edge ( 138 ) of the blades is orthogonal to the longitudinal axis, and the inlets ( 152 a ) of the air bleeding openings being arranged in an area contained between 0% and 30% of the local chord of the blades ( 148 ), measured at the level of said inlets ( 152 a ) and from the leading edges ( 138 ) of tire blades ( 148 ).
1. A turbomachine with a longitudinal axis, comprising two, respectively upstream and downstream, coaxial outer propellers,
wherein at least some blades of the upstream propeller comprise at least one internal air circulation chimney that communicates on the one hand with air-bleeding orifices in boundary layers of the at least some of the blades, and communicates on the other hand with air outflow orifices on a radially outer end thereof,
the air-bleeding orifices opening at orifice inlets on suction sides of the at least some of the blades,
the orifice inlets of the air-bleeding orifices being radially arranged only in a first area contained between 10% and 45% of a radial dimension of the at least some of the blades, the radial dimension is measured above and from a radial height of the at least some of the blades for which a tangent of a leading edge of the at least some of the blades is orthogonal to the longitudinal axis,
the orifice inlets of the air-bleeding orifices being arranged only in a second area contained between 0% and 30% of a local chord of the at least some of the blades, measured at the level of said orifice inlets and from the leading edges of the at least some of the blades.
2. The turbomachine according to claim 1 , wherein said at least one internal air circulation chimney is substantially radial.
3. The turbomachine according to claim 1 , wherein the air-bleeding orifices have an elongated or oblong cross-section.
4. The turbomachine according to claim 1 , wherein the air outflow orifices opening at the outside of the at least some of the blades at the level of orifice outlets, said orifice outlets being arranged in a third area contained between 0% and 60% of the local chord of the at least some of the blades, measured at the level of said orifice outlets and from the leading edges of the at least some of the blades.
5. The turbomachine according to claim 1 , wherein the air outflow orifices open at the outside of the at least some of the blades at orifice outlets, said orifice outlets being arranged radially in a fourth area contained between 85% and 100% of the radial dimension of the at least some of the blades, and measured from roots of the at least some of the blades.
6. The turbomachine according to claim 5 , wherein said air outflow orifices are arranged only in said fourth area of the radial dimension of the at least some of the blades.
7. The turbomachine according to claim 1 , wherein the air outflow orifices open at the suction sides of the at least some of the blades.
8. The turbomachine according to claim 7 , wherein the air outflow orifices are oriented towards the top of the at least some of the blades so that, in axial section, an angle between a radial axis of the at least some of the blades and a direction of air ejection is between 0° and 90°.
9. The turbomachine according to claim 7 , wherein the air outflow orifices are oriented on a side of the suction sides of the at least some of the blades in such a way that, in radial section, an angle between the radial axis of the at least some of the blades and a direction of air ejection is between 0° and 90°.
10. The turbomachine according to claim 1 , wherein the upstream and downstream propellers have substantially the same outer diameter.
11. The turbomachine according to claim 1 , wherein the upstream and downstream propellers are unducted and counter-rotating.
12. The turbomachine according to claim 1 , wherein the upstream and downstream propellers are ducted and counter-rotating or non-counter-rotating.