Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D29/00—Details, component parts, or accessories
  • F04D29/26—Rotors specially for elastic fluids
  • F04D29/28—Rotors specially for elastic fluids for centrifugal or helico-centrifugal pumps for radial-flow or helico-centrifugal pumps
  • F04D29/30—Vanes
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
  • F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
  • F01D5/02—Blade-carrying members, e.g. rotors
  • F01D5/04—Blade-carrying members, e.g. rotors for radial-flow machines or engines
  • F01D5/043—Blade-carrying members, e.g. rotors for radial-flow machines or engines of the axial inlet- radial outlet, or vice versa, type
  • F01D5/048—Form or construction
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D29/00—Details, component parts, or accessories
  • F04D29/26—Rotors specially for elastic fluids
  • F04D29/28—Rotors specially for elastic fluids for centrifugal or helico-centrifugal pumps for radial-flow or helico-centrifugal pumps
  • F04D29/284—Rotors specially for elastic fluids for centrifugal or helico-centrifugal pumps for radial-flow or helico-centrifugal pumps for compressors
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D29/00—Details, component parts, or accessories
  • F04D29/26—Rotors specially for elastic fluids
  • F04D29/32—Rotors specially for elastic fluids for axial flow pumps
  • F04D29/321—Rotors specially for elastic fluids for axial flow pumps for axial flow compressors
  • F04D29/324—Blades
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T50/00—Aeronautics or air transport
  • Y02T50/60—Efficient propulsion technologies, e.g. for aircraft

Definitions

• the field of the present invention is that of turbomachines and more particularly that of turbomachine compressors comprising at least one centrifugal or mixed (axial-centrifugal) compression stage.
• Aeronautical turboshaft engines and in particular helicopter turboshaft engines generally comprise a compressor of the centrifugal or mixed type, as the compression stage of the gas generator.
• These compressors are formed of moving wheels or wheels, which have a substantially axial air inlet and a more radial outlet, the vanes being fixed on a bell-shaped base, which serves as a guide to the flow of air and the deviation of the direction of entry to the exit direction. The flow thus circulates between this base and a compressor casing; it is compressed and propelled by the different vanes of the wheel.
• the head of the blades is free and positioned facing the housing, or cover, which closes the air vein.
• the trailing edge is rectilinear in the prior art and may be inclined relative to the meridian plane of the wheel passing through the root of the blade. The angle it makes with this meridian plane is referred to as the rake angle, or slope angle of the trailing edge, and is one of the relevant geometrical parameters for describing a spinning wheel impeller.
• the object of the present invention is to remedy these drawbacks by proposing a centrifugal or mixed axial-centrifugal compressor which does not have some of the drawbacks of the prior art and, in particular, which has a trailing edge with a significant slope angle. at its foot, without a phenomenon of self-engagement of the dawn head in case of contact of the latter with the lid.
• the subject of the invention is a mobile wheel for a centrifugal or mixed axial-centrifugal turbomachine compressor, comprising a base on which are fixed by their feet a plurality of blades extending between a leading edge and a trailing edge, said trailing edge being inclined at the root of the blade of an angle of inclination with respect to the meridian plane which passes through it in its foot, in the direction of rotation of said compressor, characterized in that the edge leakage present at the head of the blade an angle of slope ⁇ less than its slope angle ⁇ at the bottom of the blade.
• the wedge formed by the trailing edge and the head of the blade moves more tangentially with respect to the housing and is therefore less able to penetrate into it. accidental contact.
• the slope angle ⁇ of the trailing edge at the head of the blade is close to zero, or even zero.
• even more preferential slope angle ⁇ of the trailing edge at the head of blade is negative.
• the curvature of the trailing edge is continuously variable between the foot and the head of said trailing edge.
• the trailing edge is then in the form of a helix.
• the invention also relates to a turbomachine comprising a compressor having one of the characteristics described above. Finally, it relates to an aircraft equipped with such a turbomachine.
• FIG. 1 is a perspective view of a centrifugal compressor impeller according to one embodiment of the invention
• FIG. 2 is a front view of a trailing edge of a centrifugal compressor blade according to the prior art
• FIG. 3 is a front view of a trailing edge of a centrifugal compressor blade according to one embodiment of the invention.
• centrifugal compressor 1 comprising a base 2, bell-shaped, on which are fixed compressor blades 3 regularly distributed on the periphery of the base 2.
• the base 2 ends at its part upper, which corresponds to the plane of entry of the air to be compressed by a hub cylinder 4 for the compressor, and at its bottom by a disk 5 oriented radially relative to the axis of rotation of said compressor.
• the blades 3 are held by the base 2 at their foot 6; the heads 7 of these blades are free and rotate inside a compressor housing (not shown).
• the vanes In the direction of the flow of the air vein the vanes extend between a leading edge 8 located at the hub 4 and a trailing edge 9 located at the disc 5.
• FIG 2 shows a trailing edge 9 of a compressor blade 3, according to the prior art.
• This trailing edge is, at its foot, inclined relative to the meridian plane which passes through, in the direction of rotation, a slope angle ⁇ .
• This trailing edge 9 is rectilinear, that is to say that it has the same inclination, equal to its value ⁇ at the bottom of the blade, over its entire height, from the foot to the head of the edge of 9.
• the trailing edge 9 has an evolutionary shape along its height.
• the proposed invention thus consists in choosing, at the trailing edge 9, a slope angle ⁇ high at the blade root 6, then applying a curvature to the blade 3 so as to find a lower slope angle or even zero or negative at the head of blading.
• a high slope angle ⁇ at the blade root 6 makes it possible to reduce the bending stresses in the foot, whereas the low angle of inclination ⁇ at the level of the head 7 reduces the risks of self-engagement of the blade 3 in the housing in case of accidental contact between the head 7 of the blade at the trailing edge 9 and the housing.
• the invention therefore allows a gain in mass and inertia, or iso-mass and iso-inertia an increase in the speed of rotation, without degrading the behavior in case of contact between the blade 3 and the housing.
• the curvature may for example be constant, the trailing edge having a shape of an arc of circle, or be continuously variable, the profile of the trailing edge then having the shape of a helix.
• the choice of curvature between the foot and the head of the dawn is based on the impact it has on the aerodynamic performance of the compressor.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Structures Of Non-Positive Displacement Pumps (AREA)

Priority Applications (7)

Applications Claiming Priority (2)

Publications (1)

Family

ID=41057639

Family Applications (1)

Country Status (9)

Cited By (3)

Families Citing this family (12)

Citations (3)

Family Cites Families (9)

• 2009
  • 2009-03-13 FR FR0951604A patent/FR2943103B1/fr not_active Expired - Fee Related
• 2010
  • 2010-03-10 WO PCT/EP2010/053057 patent/WO2010103055A1/fr active Application Filing
  • 2010-03-10 RU RU2011141460/06A patent/RU2011141460A/ru unknown
  • 2010-03-10 KR KR1020117024047A patent/KR101746870B1/ko active IP Right Grant
  • 2010-03-10 EP EP10707910A patent/EP2406500A1/de not_active Withdrawn
  • 2010-03-10 JP JP2011553449A patent/JP5687215B2/ja not_active Expired - Fee Related
  • 2010-03-10 CA CA2755017A patent/CA2755017C/fr not_active Expired - Fee Related
  • 2010-03-10 US US13/256,371 patent/US20110318188A1/en not_active Abandoned
  • 2010-03-10 CN CN201080010678.8A patent/CN102341602B/zh not_active Expired - Fee Related

Patent Citations (3)

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