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
  • F04D27/00—Control, e.g. regulation, of pumps, pumping installations or pumping systems specially adapted for elastic fluids
  • F04D27/02—Surge control
• • 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
  • F04D29/40—Casings; Connections of working fluid
  • F04D29/52—Casings; Connections of working fluid for axial pumps
  • F04D29/522—Casings; Connections of working fluid for axial pumps especially adapted for elastic fluid pumps
  • F04D29/526—Details of the casing section radially opposing blade tips
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D19/00—Axial-flow pumps
• • 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
  • F04D29/08—Sealings
  • F04D29/16—Sealings between pressure and suction sides
  • F04D29/161—Sealings between pressure and suction sides especially adapted for elastic fluid pumps
  • F04D29/164—Sealings between pressure and suction sides especially adapted for elastic fluid pumps of an axial flow wheel
• • 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
  • F04D29/40—Casings; Connections of working fluid
  • F04D29/52—Casings; Connections of working fluid for axial pumps
  • F04D29/54—Fluid-guiding means, e.g. diffusers
  • F04D29/541—Specially adapted for elastic fluid pumps
• • 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
  • F04D29/40—Casings; Connections of working fluid
  • F04D29/52—Casings; Connections of working fluid for axial pumps
  • F04D29/54—Fluid-guiding means, e.g. diffusers
  • F04D29/541—Specially adapted for elastic fluid pumps
  • F04D29/542—Bladed diffusers
• • 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
  • F04D29/66—Combating cavitation, whirls, noise, vibration or the like; Balancing
  • F04D29/68—Combating cavitation, whirls, noise, vibration or the like; Balancing by influencing boundary layers
  • F04D29/681—Combating cavitation, whirls, noise, vibration or the like; Balancing by influencing boundary layers especially adapted for elastic fluid pumps
  • F04D29/685—Inducing localised fluid recirculation in the stator-rotor interface
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
  • F05D2220/00—Application
  • F05D2220/30—Application in turbines
  • F05D2220/32—Application in turbines in gas turbines
  • F05D2220/321—Application in turbines in gas turbines for a special turbine stage
  • F05D2220/3216—Application in turbines in gas turbines for a special turbine stage for a special compressor stage

Definitions

• the field of the present invention is that of propulsion and more particularly that of axial or axial-centrifugal compressors for propulsion assembly (turbojet or turboprop, referred to as turbomachines in the following description) and more specifically to high-pressure compressors heavily loaded.
• the aeronautical turbomachines are mainly constituted by one or more compressors, in which the air sucked into the air intake is compressed, by a combustion chamber in which the injected fuel is burned, then by a turbine in which the burnt gases are relaxed to drive the compressor or compressors and finally by an ejection device.
• Aeronautical compressors consist of blades, or blades, which are rotated inside a housing that seals the air stream with the outside of the engine. It is known that the clearance between the ends of the compressor blades and the casing forming the inner wall of the air flow line degrades the efficiency of the engine of the turbomachine.
• this game can significantly modify and degrade the operation of the compressor until the occurrence of a phenomenon of "pumping", which results from the stalling of the airflow from the surface of the blades.
• the control of the air circulation at the end of the blades is thus a major challenge to obtain both a good aerodynamic efficiency of the compressor and a sufficient margin against the pumping phenomenon.
• the improvement brought by this realization comes only from an optimization of the axial position of the cavities and the search for optimization on other parameters of these cavities must be pursued to try to further improve the aerodynamic efficiency and / or the pumping margin of existing compressors.
• the present invention therefore aims to provide a compressor housing with cavities, aerodynamic performance further improved.
• the subject of the invention is a compressor for a turbomachine comprising a housing, at least one compressor stage consisting of a fixed blade wheel and a blade wheel positioned downstream of said wheel.
• fixed vanes, and recessed cavities non-communicating with each other, in the thickness of said casing from its internal face and arranged parallel to each other on a circumference of said casing opposite the path of passage of the blades, said cavities having an elongated shape in a main direction of orientation and closing respectively upstream and downstream by an upstream face and a downstream face whose intersections with the housing respectively form an upstream boundary and a downstream boundary, said cavities being offset relative to the blades to overflow upstream of the blade wheel by covering their upstream end, characterized in that the front The downstream of these cavities is oriented parallel to the rope at the head of the moving blade.
• the orientation direction of said cavities is perpendicular to that of the rope of the blades.
• the substantially parallelepipedal shape of the cavity makes it possible to make full use of the thrust effect indicated above.
• the cavities are evenly distributed around the circumference of the casing.
• the cavities are distributed unevenly over the circumference of the housing.
• the invention also relates to a turbomachine comprising a compressor as described above.
• Figure 1 is a schematic sectional view of a compressor stage whose housing has a recirculating cavity of the air flowing between the blade and the housing;
• Figure 2 is a schematic view, from above, of a rotor blade and a housing according to the prior art
• Figure 3 is a schematic view, from above, of a rotor blade and a housing according to one embodiment of the invention
• Figure 4 is a schematic comparative view of the positioning of a cavity and a blade in the invention and in the prior art
• FIG. 5 is a perspective view of the cavities and blades of a rotor according to the prior art.
• Figure 6 is a perspective view of the cavities and blades of a rotor according to the invention.
• FIG. 1 there is shown a compressor stage comprising a stator vane, or fixed vane 2, positioned upstream of a rotor vane, or mobile vane 1, attached to a disk 3 (or directly attached to this disk according to a so-called blisk technology monobloc).
• the vanes are held in place by attachment to a compressor casing 4, which surrounds the blades 1 leaving a predefined clearance with them.
• the casing 4 is dug, from its internal face, multiple cavities 5, not communicating with each other, which are regularly arranged on its circumference, vis-à-vis the path of passage of the blades 1.
• These cavities have, roughly, the shape of a rectangular parallelepiped which sinks radially into the housing and which has in section along an axial plane, the shape of a rectangle with rounded corners.
• Their shape, in section in a plane tangential to the circumference of the housing is, in turn, substantially that of an elongated rectangle extending along two long sides and comprising, upstream and downstream, two small sides forming so-called upstream 7 and downstream borders 6. These two boundaries are classically straight line segments.
• the cavities are offset upstream of the motor, with respect to the leading edge of the moving blade 1.
• the length of which the upstream of the cavity exceeds the edge of attack 1 1 of the blades, is however, limited by the space between the blade wheel 1 and the blade wheel 2.
• This configuration allows the recycling of air passing in the game between the blade 1 and the casing 4; this game can indeed be the place of violent turbulence which would disturb the configuration of the flow between the different stages and therefore which could lead to a deterioration of the performances of the compressor or, in the extreme, cause a phenomenon called "pumping" or of "stall".
• Such a phenomenon is characterized by an instantaneous drop in the compression ratio and a transient inversion of the air flow through the compressor, which then leaves the upstream of the compressor.
• FIGS. 2 and 3 the circumferential position of a series of cavities 5 aligned along the casing 4 is seen.
• the number of cavities is much greater than the number of blades 1 constituting the moving wheel of the stage. of compressor. This number is in practice between 2 and 4 times the number of blades 1.
• the circumferential distribution of the cavities as shown in the figures is a uniform arrangement; it has, moreover, already been proposed to make this provision irregular to break the aerodynamic excitation on the blades that could be caused by these cavities, especially at the ends of each of the two half-shells that constitute the housing.
• FIG. 2 representing the prior art
• the axis of these cavities is slightly inclined with respect to the longitudinal direction of the motor, defined as being the axis of rotation of the mobile wheel 1 and illustrated by an arrow in FIG. .
• the cavities 5 are positioned with the main orientation of their long sides which is clearly more tangential than in FIG. 2, and which is characterized by an angle wedging perpendicular to the rope of moving blades 1.
• the rope of a blade is defined as the line joining its leading edge to its trailing edge.
• the cavity has, in the example shown, a substantially parallelepiped shape, the downstream boundary 6 of the cavity 5 is aligned with this rope of the blades.
• Figures 5 and 6 show in perspective, and recessed, the relative position of the cavities 5 with respect to a blade wheel 1, respectively in the prior art and according to the invention.
• the invention is characterized by an orientation of the main direction of the cavity 5 which is perpendicular to that of the rope of the blades 1.
• the main characteristic of the invention is defined primarily as a parallelism between the downstream border 6 of the cavity 5 and the rope of the vane 1.
• the downstream boundary of a cavity when it is not rectilinear, is defined, as for it, as the line segment connecting the extreme endpoints of the long sides forming the intersection of the cavity with the inner wall of the casing 4.
• the first concerns the axial position of the downstream cavity, which defines the location air suction, the second, the axial position of the upstream cavity that defines the place of reinjection of air and the third, the volume of the cavity that determines the amount of air removed and reinjected, thus the efficiency of the crankcase treatment.
• the invention first sought to reduce the axial extension of the cavities and for this analyzed the influence of the wedging thereof on the 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)

Applications Claiming Priority (2)

Publications (2)

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Family Applications (1)

Country Status (9)

Families Citing this family (19)

Family Cites Families (15)

• 2012
  • 2012-04-19 FR FR1201159A patent/FR2989744B1/fr active Active
• 2013
  • 2013-04-15 EP EP13742668.0A patent/EP2859239B1/de active Active
  • 2013-04-15 WO PCT/FR2013/050828 patent/WO2013156725A2/fr not_active Ceased
  • 2013-04-15 RU RU2014141506A patent/RU2616695C2/ru active
  • 2013-04-15 CN CN201380019881.5A patent/CN104220759B/zh active Active
  • 2013-04-15 JP JP2015506286A patent/JP6618799B2/ja active Active
  • 2013-04-15 US US14/390,178 patent/US10024336B2/en active Active
  • 2013-04-15 CA CA2868226A patent/CA2868226C/fr active Active
  • 2013-04-15 BR BR112014025631-4A patent/BR112014025631B1/pt active IP Right Grant

Non-Patent Citations (1)

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