CN118088496B - Auxiliary power device for aircraft, blade spanwise gamma-shaped thickness distribution wedge-shaped diffuser and forming method thereof - Google Patents

Auxiliary power device for aircraft, blade spanwise gamma-shaped thickness distribution wedge-shaped diffuser and forming method thereof Download PDF

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Publication number
CN118088496B
CN118088496B CN202410524652.9A CN202410524652A CN118088496B CN 118088496 B CN118088496 B CN 118088496B CN 202410524652 A CN202410524652 A CN 202410524652A CN 118088496 B CN118088496 B CN 118088496B
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Prior art keywords
blade
sweepback
root
thickness
diffuser
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CN118088496A (en
Inventor
张小龙
吴永鑫
王海朋
常国强
陈敏
徐夏
吴斌
陈强
叶珍良
梁中汉
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Rongtong Aviation Engine Technology Co ltd
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Rongtong Aviation Engine Technology Co ltd
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    • 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
    • F04D29/42—Casings; Connections of working fluid for radial or helico-centrifugal pumps
    • F04D29/44—Fluid-guiding means, e.g. diffusers
    • F04D29/441—Fluid-guiding means, e.g. diffusers especially adapted for elastic fluid pumps
    • F04D29/444—Bladed diffusers
    • 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
    • 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
    • F05D2240/00—Components
    • F05D2240/10—Stators
    • F05D2240/12—Fluid guiding means, e.g. vanes
    • F05D2240/121—Fluid guiding means, e.g. vanes related to the leading edge of a stator vane
    • 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
    • F05D2240/00—Components
    • F05D2240/10—Stators
    • F05D2240/12—Fluid guiding means, e.g. vanes
    • F05D2240/122—Fluid guiding means, e.g. vanes related to the trailing edge of a stator vane
    • 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
    • F05D2240/00—Components
    • F05D2240/10—Stators
    • F05D2240/12—Fluid guiding means, e.g. vanes
    • F05D2240/125—Fluid guiding means, e.g. vanes related to the tip of a stator vane

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

Abstract

The invention discloses an aircraft auxiliary power device, a blade spanwise gamma-shaped thickness distribution wedge-shaped diffuser and a forming method thereof, and belongs to the field of aeroengines. The device comprises a diffuser wheel cover and a plurality of sweepback blades, wherein the sweepback blades are uniformly distributed on the diffuser wheel cover along the circumferential direction; the radius of the arc of the tail edge of the root of the sweepback blade is larger than that of the front edge of the root of the sweepback blade; the thickness of the front edge of the tip of the sweepback blade is equal to that of the front edge of the root of the sweepback blade, and the thickness of the tail edge of the tip of the sweepback blade is larger than that of the tail edge of the root of the sweepback blade; the radius of the arc of the tail edge of the tip of the sweepback blade is larger than that of the tail edge of the root of the sweepback blade; the radius of the circular arc of the front edge of the tip of the sweepback blade is equal to that of the front edge of the root of the sweepback blade. The invention can improve the adaptability of the wedge-shaped diffuser to non-uniform incoming flow, reduce flow separation and improve the pressure expansion capacity, thereby further improving the performance and the working reliability of the auxiliary power device of the airplane.

Description

Auxiliary power device for aircraft, blade spanwise gamma-shaped thickness distribution wedge-shaped diffuser and forming method thereof
Technical Field
The invention relates to a power device and a radial diffuser, in particular to an auxiliary power device for an aircraft, a wedge-shaped diffuser with a thickness distribution of a blade spanwise gamma-shaped structure and a forming method thereof, and belongs to the field of aeroengines.
Background
An aircraft Auxiliary Power Unit (APU) is a small power unit on an aircraft that can independently output power or compressed air independently of the main power unit, typically in the form of a small gas turbine engine. The main components of the APU comprise a power output shaft, a speed reducer, a gas compressor, a combustion chamber, a turbine and a tail nozzle. In order to adapt to the characteristics of simple and compact structure, the air compressor of the auxiliary power device of the airplane is generally in the form of a single-stage centrifugal air compressor.
The centrifugal compressor generally comprises a centrifugal impeller, a radial diffuser and an axial centrifugal compressor, wherein the wedge-shaped diffuser is a radial diffuser with wedge-shaped blades, and has the advantages of simple structure, convenient processing and the like, and is widely used in auxiliary power devices of airplanes because the wedge-shaped front edge of the wedge-shaped diffuser is suitable for high-speed airflow. In order to adapt to the development directions of light weight, compact structure and low cost of the advanced aircraft auxiliary power device in the future, the centrifugal compressor also develops to the directions of higher pneumatic load, higher pneumatic efficiency and more compact size.
In a compact high-load centrifugal compressor, the impeller outlet airflow has obvious non-uniformity along the expanding direction, and the impeller outlet airflow presents the characteristics of large shroud side airflow angle, low Mach number, small hub side airflow angle and high Mach number, which causes the pneumatic load of the blades to present the characteristics of high shroud side and low hub side along the expanding direction. The traditional wedge-shaped diffuser is a straight blade, the spanwise blade profiles are identical, the diffuser cannot adapt to different pneumatic loads at different spanwise positions, the suction surface of the blade at the side of the near wheel cover is easy to generate larger airflow separation, and the flow loss is serious. In addition, under the constraint of compact size, the diffusion edge of the diffuser is short, the reverse pressure gradient is large, and the design difficulty of the diffuser is further improved.
In order to solve the problems that the traditional wedge-shaped diffuser in the compact high-load centrifugal compressor has poor adaptability to uneven incoming flow and is easy to generate larger flow loss, students at home and abroad have explored.
The Chinese patent application No. CN201310714361.8 discloses a vane diffuser with a horseshoe-shaped diffusion channel, which adopts vanes with the horseshoe-shaped diffusion channel to reduce the expansion degree of the channel area at the wheel cover side; the dovetail-shaped front edge of the wheel cover side is adopted, the diffusion edge of the wheel cover side is increased, the adaptability of the blade to non-uniform incoming flow can be greatly improved by the two structures, and the efficiency of the air compressor is improved on the premise that the processing cost is not increased. But this has the following problems: (1) The horseshoe-shaped diffusion channel symmetrically increases the thickness of the blade on both sides of the pressure surface and the suction surface of the blade, but the air flow separation mostly occurs on the suction surface of the blade, and the modeling cannot adaptively improve the blade structure according to the flow field characteristics; (2) The dovetail-shaped front edge extends forward and gradually thins the front edge of the blade on the shroud side, and increases the diffusion path of the shroud side. In a compact high-load centrifugal compressor, the impeller outlet is closer to the diffuser inlet, so that the airflow at the front edge of the diffuser has high Mach number, the unsteady effect is obvious, and fatigue fracture of the blades at the thinner dovetail-shaped front edge is extremely easy to occur.
The Chinese patent application No. CN201810128459.8 discloses a centrifugal compressor diffuser structure with blades integrated with a casing and a hub, wherein three-dimensional torsion blades are used, the blades are integrated with the casing and the hub, and the adaptability of the diffuser to uneven inflow is improved; meanwhile, the radial diffuser blades and the axial diffuser blades are connected into a whole, the diffusion path is increased, and the counter pressure gradient is reduced, so that the performance of the diffuser is improved. However, the diffuser blade in the technical scheme has a very complex structure, and the processing cost is greatly increased.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provide the auxiliary power device of the aircraft, the blade span-wise gamma-shaped thickness distribution wedge-shaped diffuser and the forming method thereof, which have the advantages of good adaptability to non-uniform incoming flow, stability, reliability, simple structure and low processing cost.
In order to solve the technical problems, the auxiliary power device for the aircraft comprises a radial diffuser, wherein the radial diffuser comprises a diffuser wheel cover and a plurality of sweepback blades, and the sweepback blades are uniformly distributed on the diffuser wheel cover along the circumferential direction;
The ratio RHT 2/RHL2=1.15-1.25 of the arc radius RHT2 of the tail edge of the root of the sweepback blade to the arc radius RIL 2 of the front edge of the root of the sweepback blade;
the thickness TTL2 of the front edge of the tip of the sweepback blade is equal to the thickness THL2 of the front edge of the root of the sweepback blade, and the thickness TTT2 of the tail edge of the tip of the sweepback blade is larger than the thickness THT2 of the tail edge of the root of the sweepback blade;
The circular arc radius RTT2 of the tail edge of the tip of the sweepback blade is larger than the circular arc radius RHT2 of the tail edge of the root of the sweepback blade, the value range is RTT 2/RHT2=1.06-1.02, and the sweepback blade is in a sweepback shape;
The arc radius RTL2 of the front edge of the tip of the sweepback blade is equal to the arc radius RIL 2 of the front edge of the root of the sweepback blade.
In the invention, the diffuser wheel cover comprises a straight section, and the sweepback blades are uniformly distributed on the straight section along the circumferential direction.
In the invention, the diffuser wheel cover comprises a straight section, and the sweepback blades are uniformly distributed on the straight section along the circumferential direction.
The invention also provides a wedge-shaped diffuser with the thickness distribution of the blade spanwise gamma-shaped, which comprises a diffuser wheel cover and a plurality of sweepback blades, wherein the sweepback blades are uniformly distributed on the diffuser wheel cover along the circumferential direction;
The ratio RHT 2/RHL2=1.15-1.25 of the arc radius RHT2 of the tail edge of the root of the sweepback blade to the arc radius RIL 2 of the front edge of the root of the sweepback blade;
the thickness TTL2 of the front edge of the tip of the sweepback blade is equal to the thickness THL2 of the front edge of the root of the sweepback blade, and the thickness TTT2 of the tail edge of the tip of the sweepback blade is larger than the thickness THT2 of the tail edge of the root of the sweepback blade;
The circular arc radius RTT2 of the tail edge of the tip of the sweepback blade is larger than the circular arc radius RHT2 of the tail edge of the root of the sweepback blade, the value range is RTT 2/RHT2=1.06-1.02, and the sweepback blade is in a sweepback shape;
The arc radius RTL2 of the front edge of the tip of the sweepback blade is equal to the arc radius RIL 2 of the front edge of the root of the sweepback blade.
The invention provides a forming method of a wedge-shaped diffuser with a blade spanwise gamma-shaped thickness distribution, which comprises the following steps:
S1: carrying out three-dimensional modeling of the blade without sweepback;
s2: and trimming the tail edge of the unbroken blade after finishing to form the unbroken blade.
In the invention, the three-dimensional modeling of the non-swept blade in the S1 adopts a three-dimensional modeling mode of combining independent molding of the tip of the non-swept blade and the root of the non-swept blade with spanwise thickness distribution.
In the invention, the blade profile of the tip part of the sweepless blade and the blade profile of the root part of the sweepless blade adopt the modeling modes of camber line, suction surface thickness distribution and pressure surface thickness distribution;
The camber line of the blade tip is the same as the camber line of the blade root;
The thickness distribution of the pressure surface of the blade root, the suction surface of the blade root and the pressure surface of the blade tip are the same;
The thickness distribution of the suction surface of the blade tip adopts a similar trend to that of the pressure surface of the blade tip, the thickness TTLS3 at the suction front edge of the blade tip is the same as the thickness THLS at the suction front edge of the blade root, the thickness TTTS3 at the tail edge of the suction surface of the blade tip is larger than the thickness THTS3 at the tail edge of the suction surface of the blade root, and the value range is TTTS/THTS 3=1.4-2.0.
In the invention, in the spanwise thickness distribution, the spanwise thickness distribution of the suction surface of the tail edge of the blade tip and the tail edge of the blade root is controlled, the distribution curve is described by adopting a fourth-order Bezier curve, and the coordinates P of any point on the curve are the sameThe parametric equation for (2) is:
Wherein, For the thickness value,/>Is relative spanwise position,/>Is an argument of a parameter equation; (/ >,/>)、(/>,)、(/>,/>)、(/>,/>)、(/>,/>) The coordinates of four-order Bezier curve control points P0 to P4 are respectively, wherein P0 is%,/>) P4 (/ >) is the blade trailing edge suction surface root thickness control point,/>) For controlling the thickness of the tip of the suction surface of the trailing edge of the blade, i.e./>=TTTS3，/>=1; P0 to P4 are uniformly distributed in the spreading direction, and the thickness coordinates of P0 to P3 are equal.
In the invention, in the step S2, a trimming curved surface is formed by circumferential rotation of the trimming line, and the part of the blade exceeding the trimming curved surface is trimmed.
In the invention, the trimming line is described by adopting a third-order Bezier curve, and the coordinate Q of any point on the curveThe expression of (2) is:
is radial coordinate,/> Is relative spanwise position,/>Is an argument of a parameter equation; (/ >,/>)、(/>,/>)、(/>,/>) Coordinates of curve control points Q0, Q1 and Q2 respectively; wherein Q0 (/ >),/>) The control point is an arc radius control point where the root of the tail edge of the blade is positioned; q2 (/ >),/>) And the tip of the tail edge of the blade is positioned at an arc radius control point.
The invention has the beneficial effects that: (1) The expansion degree of inlet and outlet areas of different expansion positions of the diffuser is changed through the thickness distribution control and the sweepback modeling of the vane expansion direction, and the invention is applicable to compact high-load centrifugal compressors, can greatly improve the adaptability of the wedge-shaped diffuser to uneven inflow, reduce flow separation, improve the expansion capacity, and further improve the efficiency and stability of an auxiliary power device of an airplane; (2) The front edge of the blade has no glancing shape, so that the fatigue fracture of the blade at the front edge caused by the action of unsteady aerodynamic force is avoided, and the working stability and reliability of the diffuser are further ensured; (3) Compared with the traditional straight-blade wedge-shaped diffuser, through simulation calculation, the invention can improve the efficiency of the compressor by 1.1 percent and the stable working margin by 2.5 percent under the same pneumatic load and size constraint, and meanwhile, the processing cost is not increased; (4) The auxiliary power device for the aircraft provided by the invention is stable in operation and can be widely applied to various aircrafts.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments or the prior art will be briefly described, and it is obvious that the drawings in the description below are some embodiments of the present invention, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic view of an aircraft auxiliary power unit;
FIG. 2 is a schematic view of the overall structure of a wedge diffuser with a blade spanwise Γ -shaped thickness distribution;
FIG. 3 is a three-dimensional semi-sectional view of the blade spanwise Γ -shaped thickness distribution as a whole;
FIG. 4 is a block diagram of a single swept blade line;
FIG. 5 is a radial cross-sectional view of a wedge diffuser with a blade spanwise Γ -shaped thickness distribution;
FIG. 6 is a three-dimensional comparative line block diagram of a no sweep blade versus a sweep blade;
FIG. 7 is a three-dimensional line block diagram 1 of a swept-free blade;
FIG. 8 is a three-dimensional line block diagram 2 of a swept-back free blade;
FIG. 9 is a schematic view of a spanwise thickness profile of a suction side of a trailing edge of a swept-free blade;
FIG. 10 is a schematic view of a tail edge trim profile of a swept-free blade;
FIG. 11 is a schematic view of an assembly of the present vane spanwise Γ -thickness distribution wedge diffuser with an axial diffuser;
In the figure, A1-radial diffuser, A2-turbine, A3-centrifugal impeller, A4-combustion chamber, A5-tail nozzle, A6-speed reducer, A7-power output shaft, A8-main shaft, 1-diffuser shroud, 2-swept blade, 3-swept blade, 4-axial diffuser, 11-straight section, 12-turning section, 21-swept blade tip, 22-swept blade root, 31-swept blade tip, 32-swept blade root, 311-blade tip pressure surface, 312-blade tip suction surface, 313-blade tip camber line, 321-blade root pressure surface, 322-blade root suction surface, 323-blade root camber line.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention. The components of the embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.
Thus, the following detailed description of the embodiments of the invention, as presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures.
In the description of the present invention, it should be noted that, directions or positional relationships indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., are directions or positional relationships based on those shown in the drawings, or are directions or positional relationships conventionally put in use of the inventive product, are merely for convenience of describing the present invention and simplifying the description, and are not indicative or implying that the apparatus or element to be referred to must have a specific direction, be constructed and operated in a specific direction, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used merely to distinguish between descriptions and should not be construed as indicating or implying relative importance.
Furthermore, the terms "horizontal," "vertical," "overhang," and the like do not denote a requirement that the component be absolutely horizontal or overhang, but rather may be slightly inclined. As "horizontal" merely means that its direction is more horizontal than "vertical", and does not mean that the structure must be perfectly horizontal, but may be slightly inclined.
In the description of the present invention, it should also be noted that, unless explicitly specified and limited otherwise, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.
Some embodiments of the present invention are described in detail below with reference to the accompanying drawings. The following embodiments and features of the embodiments may be combined with each other without conflict.
An aircraft Auxiliary Power Unit (APU) is a small power unit on an aircraft that can independently output power or compressed air independent of the main power unit, typically in the form of a small gas turbine engine. With the continuous development of aerospace technology, light weight and low cost are one of the developments of advanced APUs in the future.
As shown in fig. 1 and 11, the auxiliary power unit for an aircraft provided in this embodiment adopts a compact high-load centrifugal compressor. The device mainly comprises a radial diffuser A1, an axial diffuser 4, a turbine A2, a centrifugal impeller A3, a combustion chamber A4, a tail nozzle A5, a speed reducer A6, a power output shaft A7 and a main shaft A8. One end of the main shaft A8 is connected with an output shaft A7 through a speed reducer A6, and a centrifugal compressor consisting of a radial diffuser A1, an axial diffuser 4, a turbine A2 and a centrifugal impeller A3 is assembled on the main shaft A8. It should be noted that, the existing auxiliary power device for an aircraft adopting the structure of the turbojet engine basically includes an air inlet channel, a centrifugal compressor, a combustion chamber A4, a tail nozzle A5 and other components, which are several basic components of the turbojet engine, and the specific connection relation of the existing structure is not described in detail in this embodiment. The radial diffuser A1 in the embodiment adopts a wedge-shaped diffuser with the thickness distribution of the blade in the span-wise gamma-shaped direction, and the wedge-shaped diffuser has good adaptability to uneven incoming flow, so that flow separation is reduced, the pressure expansion capacity and the efficiency of a gas compressor are improved, and the efficiency of an auxiliary power device of an airplane is further improved.
As shown in fig. 2 and 3, the vane span-wise Γ -shaped thickness distribution wedge-shaped diffuser of the present embodiment includes a diffuser shroud 1 and a plurality of swept-back vanes 2. The diffuser shroud 1 comprises a straight section 11 and a turning section 12, the straight section 11 being located inside the turning section 12, in this embodiment the diffuser shroud 1 is integrally formed.
As shown in fig. 2 and 3, a plurality of swept blades 2 are circumferentially distributed on the straight section 11 of the diffuser shroud 1, and the swept blade tips 21 are integrally connected to the straight section 11 of the diffuser shroud 1.
As shown in fig. 5, in the present embodiment, the ratio of the radius RHT2 of the circular arc where the trailing edge of the swept blade root 22 is located to the radius RHL2 of the circular arc where the leading edge of the swept blade root 22 is located is defined to be 1.2.
Through simulation test, the reasonable range of the ratio of the arc radius RHT2 of the tail edge of the sweepback blade root 22 to the arc radius RHL2 of the front edge of the sweepback blade root 22 is 1.15-1.25, namely RHT 2/RHL2=1.15-1.25.
In a compact high-load centrifugal compressor, radial diffuser blades exhibit a high shroud-side aerodynamic load and a low hub-side aerodynamic load distribution in the spanwise direction due to significant non-uniformity of impeller outlet airflow in the spanwise direction. To accommodate different loads, it is common practice to employ different blade angles for different deployment positions, but this can lead to three-dimensional twisting of the blade, resulting in increased processing costs. For the diffuser, the inlet-outlet area ratio may reflect the load of the diffuser, and the blade load may also be adjusted by adjusting the blade thickness, so that the swept-back blade 2 is defined to have a spanwise non-uniform thickness in this embodiment, where the thickness TTL2 of the front edge of the swept-back blade tip 21 is the same as the thickness THL2 of the front edge of the root of the swept-back blade tip 21, and the thickness TTT2 of the rear edge of the swept-back blade tip 21 is greater than the thickness THT2 of the rear edge of the root of the swept-back blade tip 21, as shown in fig. 4. The inlet and outlet area expansion degree of the blade tip is smaller than that of the blade root by adopting the modeling, so that the adaptability to non-uniform incoming flow is improved.
Because the radial diffuser in the compact high-load centrifugal compressor has small inlet-outlet radius ratio, very compact radial space, short diffusion path and large reverse pressure gradient, in the embodiment, the blade adopts a sweepback shape, the circular arc radius RTT2 of the tail edge of the limited sweepback blade tip 21 is larger than the circular arc radius RHT2 of the tail edge of the sweepback blade root 22, and RTT2/RHT 2=1.03, as shown in fig. 5. The blade adopts a sweepback shape, the diffusion edge of the sweepback blade tip 21 is increased, and the aerodynamic load of the sweepback blade tip 21 is further reduced, so that the adaptability to non-uniform incoming flow is improved.
Through simulation test, the reasonable range of the ratio of the circular arc radius RTT2 of the tail edge of the sweepback blade tip 21 to the circular arc radius RHT2 of the tail edge of the sweepback blade root 22 can be controlled between 1.06 and 1.02, namely RTT 2/RHT2=1.06 to 1.02.
In this embodiment, the radius RTL2 of the arc where the leading edge of the swept blade tip 21 is located is equal to the radius RHL2 of the arc where the leading edge of the swept blade root 22 is located, i.e., rtl2=rhl2, as shown in fig. 5. The front edge of the blade has no glancing shape, and the fatigue fracture of the blade at the front edge caused by the action of unsteady pneumatic force can be avoided, thereby ensuring the working stability and reliability of the centrifugal compressor.
The forming method of the wedge-shaped diffuser with the thickness distribution of the span-wise gamma-shaped blades in the embodiment is as follows: in order to facilitate the blade forming and avoid the concave profile in the extending direction of the blade, the processing cost is increased, the embodiment proposes that the three-dimensional modeling of the non-swept blade 3 is firstly carried out, after the three-dimensional modeling of the non-swept blade 3 is completed, the tail edge of the non-swept blade 3 is trimmed to form the swept blade 2, and finally the swept blade 2 and the diffuser wheel cover 1 are integrally formed.
Step one: a three-dimensional shaping of the swept blade 3 is performed. As shown in fig. 5 and 6, fig. 5 illustrates an arc radius RTL2 where the front edge of the tip 21 of the swept blade, an arc radius RTT2 where the tail edge of the tip 21 of the swept blade, an arc radius RHL2 where the root front edge of the tip 21 of the swept blade, an arc radius RHT2 where the tail edge of the tip 21 of the swept blade, an arc radius RTT3 where the tail edge of the blade tip 3 of the non-swept blade, and an arc radius RHT3 where the tail edge of the blade root 3 of the non-swept blade are located. In this embodiment, the radius RHT3 of the circular arc where the trailing edge of the blade root 32 without sweepback is located is the same as the radius RTT3 of the circular arc where the trailing edge of the blade tip 31 without sweepback is located, i.e. rtt3=rht3=rtt2.
As can be seen by comparing fig. 5 and 6, the dotted line portion, i.e., the portion of the non-swept blade 3 that needs to be trimmed compared to the swept blade 2.
The three-dimensional shaping of the swept blade 3 is described in detail below: in this embodiment, the swept-free blade 3 adopts a three-dimensional modeling mode in which the blade tip and the blade root are independently molded and combined with spanwise thickness distribution. Because the flowing states of the air flow on the pressure surface and the suction surface are not consistent, the thickness of the pressure surface and the suction surface of the blade are independently controlled, namely, the blade tip blade profile and the blade root blade profile adopt a modeling mode of mean camber line, suction surface thickness distribution and pressure surface thickness distribution. In this embodiment, in order to avoid twisting of the blade, which leads to an increase in processing cost, the blade tip camber line 313 is set to be the same as the blade root camber line 323. The non-swept blade tip 31, blade tip pressure surface 311, blade tip suction surface 312, blade tip camber line 313, blade root pressure surface 321, blade root suction surface 322, blade root camber line 323, are shown in FIG. 7.
As shown in fig. 8, the thickness of the suction surface of the front edge of the tip 31 of the non-swept blade is TTLS3, the thickness of the suction surface of the tail edge of the tip 31 of the non-swept blade is TTTS3, the thickness of the suction surface of the front edge of the root 32 of the non-swept blade is THLS3, and the thickness of the suction surface of the tail edge of the root 32 of the non-swept blade is THTS3.
As shown in fig. 7 and 8, the thickness distributions of the blade root pressure surface 321, the blade root suction surface 322 and the blade tip pressure surface 311 are the same, the thickness distribution of the blade tip suction surface 312 adopts a similar trend as the thickness distribution of the blade tip pressure surface 311, except that the thickness TTLS3 at the front edge of the blade tip suction surface 312 is the same as the thickness THLS at the front edge of the blade root suction surface 322, the thickness TTTS3 at the tail edge of the blade tip suction surface 312 is greater than the thickness THTS3 at the tail edge of the blade root suction surface 322, and the value range is TTTS 3/thts3=1.4-2.0, in this embodiment TTTS/thts3=1.5.
In spanwise direction, separation is mainly concentrated on the diffuser shroud side, so in the spanwise thickness distribution, the suction side spanwise thickness distribution of the blade tip trailing edge and the blade root trailing edge is controlled. In this embodiment, the distribution curve is described by a fourth-order Bezier curve, and the coordinates P of any point on the curveThe parametric equation for (2) is:
For the thickness value,/> Is relative spanwise position,/>Is an argument of the parameter equation. (/ >,/>)、(/>,/>)、(,/>)、(/>,/>)、(/>,/>) Coordinates of four-order Bezier curve control points P0 to P4, respectively, wherein P0 (/ >),/>) For controlling the root thickness of the suction surface of the trailing edge of the blade, i.e./>=THTS3，/> =0，P4(/>,/>) For controlling the thickness of the tip of the suction surface of the trailing edge of the blade, i.e./>=TTTS3，/>=1. P0 to P4 are uniformly distributed in the spanwise direction, namely/>=0.25，/> =0.5，/>The thickness coordinates of P0 to P3 are equal, i.e./>, 0.75=/>=/>=/>. Thus, the trailing edge suction side exhibits a Γ -shape in the spanwise thickness profile.
The trailing edge suction side spanwise thickness profile of the swept-free blade 3 is shown in fig. 9, which illustrates the distribution of control points P0-P4 of the profile.
Step two: after the three-dimensional modeling of the non-swept blade 3 is completed, the non-swept blade 3 is trimmed to form a swept blade 2. And a trimming curved surface is formed by circumferential rotation of the trimming molded line, and the part of the blade exceeding the trimming curved surface is trimmed, so that the radius RHT2 of the tail edge arc of the root of the blade is equal to the radius of the inlet hub of the downstream axial diffuser 4. The assembly of the wedge diffuser with the axial diffuser 4 is shown in fig. 11. Because the radial space of the radial diffuser is compact, the diffusion edge of the radial diffuser is increased to fully utilize the space at the turning part, and the trimming line is controlled.
In this embodiment, a third-order Bezier curve is used to describe a trimming line, and the coordinates Q of any point on the trimming lineThe parametric equation for (2) is:
is radial coordinate,/> Is relative spanwise position,/>Is an argument of the parameter equation. (/ >,/>)、(/>,)、(/>,/>) The coordinates of the curve control points Q0, Q1 and Q2 are shown in fig. 10. Wherein Q0 (/ >),/>) Is the arc radius control point of the root of the tail edge of the blade, namely/>= RHT2，/> =0，Q2(/>,/>) The radius control point of the arc where the tip of the tail edge of the blade is positioned is/>= RTT2，/> =1。/>=/>In this embodiment, the flow field characteristics are defined/>, based on=0.1 To 0.25, i.e. the sweep line is convex.
Step three: and (3) integrally forming the sweepback blade 2 formed in the step (2) and the diffuser wheel cover (1). The integral molding mode can be realized by adopting the conventional technical means in the prior art, so the embodiment is not described here.
According to the technical scheme provided by the embodiment, through the thickness distribution control and the sweepback modeling of the vane, the inlet and outlet area expansion degree of different spanwise positions of the wedge-shaped diffuser is changed, so that the wedge-shaped diffuser is suitable for various compact high-load centrifugal compressors, the adaptability of the diffuser to uneven incoming flows can be improved, the flow separation is reduced, the pressure expansion capacity is improved, and the efficiency of the compressor is further improved. Through simulation calculation, compared with a traditional straight-blade wedge-shaped diffuser, the technical scheme of the embodiment can improve the efficiency of the compressor by 1.1% and the stable working margin by 2.5% under the same pneumatic load and size constraint, and meanwhile, the processing cost is not increased.
The invention provides an aircraft auxiliary power device, a blade spanwise gamma-shaped thickness distribution wedge-shaped diffuser and a thought of a forming method thereof, and a method and a way for realizing the technical scheme are numerous, the above is only a preferred embodiment of the invention, and it should be pointed out that a plurality of improvements and modifications can be made by those skilled in the art without departing from the principle of the invention, and the improvements and the modifications are also regarded as the protection scope of the invention. The components not explicitly described in this embodiment can be implemented by using the prior art.

Claims (9)

1. An aircraft auxiliary power unit comprising a radial diffuser (A1), characterized in that: the novel diffuser comprises a diffuser wheel cover (1) and a plurality of sweepback blades (2), wherein the sweepback blades (2) are uniformly distributed on the diffuser wheel cover (1) along the circumferential direction;
the arc radius RHT2 of the tail edge of the sweepback blade root (22) is larger than the arc radius RIL 2 of the front edge of the sweepback blade root (22);
The thickness TTL2 of the front edge of the tip part (21) of the sweepback blade is equal to the thickness THL2 of the front edge of the root part (22) of the sweepback blade, and the thickness TTT2 of the tail edge of the tip part (21) of the sweepback blade is larger than the thickness THT2 of the tail edge of the root part (22) of the sweepback blade;
The circular arc radius RTT2 of the tail edge of the tip part (21) of the sweepback blade is larger than the circular arc radius RHT2 of the tail edge of the root part (22) of the sweepback blade, and the sweepback blade is in a sweepback shape;
The arc radius RTL2 of the front edge of the tip part (21) of the sweepback blade is equal to the arc radius RHL2 of the front edge of the root part (22) of the sweepback blade;
RHT 2/rhl2=1.15 to 1.25; RTT 2/rht2=1.06-1.02.
2. An aircraft auxiliary power unit as defined in claim 1, wherein: the diffuser wheel cover (1) comprises a straight section (11), and the sweepback blades (2) are uniformly distributed on the straight section (11) along the circumferential direction.
3. A blade spanwise gamma-shaped thickness distribution wedge-shaped diffuser is characterized in that: the novel diffuser comprises a diffuser wheel cover (1) and a plurality of sweepback blades (2), wherein the sweepback blades (2) are uniformly distributed on the diffuser wheel cover (1) along the circumferential direction;
the arc radius RHT2 of the tail edge of the sweepback blade root (22) is larger than the arc radius RIL 2 of the front edge of the sweepback blade root (22);
The thickness TTL2 of the front edge of the tip part (21) of the sweepback blade is equal to the thickness THL2 of the front edge of the root part (22) of the sweepback blade, and the thickness TTT2 of the tail edge of the tip part (21) of the sweepback blade is larger than the thickness THT2 of the tail edge of the root part (22) of the sweepback blade;
The circular arc radius RTT2 of the tail edge of the tip part (21) of the sweepback blade is larger than the circular arc radius RHT2 of the tail edge of the root part (22) of the sweepback blade, and the sweepback blade is in a sweepback shape;
The arc radius RTL2 of the front edge of the tip part (21) of the sweepback blade is equal to the arc radius RHL2 of the front edge of the root part (22) of the sweepback blade;
RHT 2/rhl2=1.15 to 1.25; RTT 2/rht2=1.06-1.02.
4. A method of forming a vane spanwise Γ -shaped thickness-profile wedge diffuser as claimed in claim 3, comprising the steps of:
s1: carrying out three-dimensional modeling of the non-sweepback blade (3);
S2: and trimming the tail edge of the unbroken blade (3) after finishing to form the unbroken blade (2).
5. The method for forming a wedge diffuser with a radial-span Γ thickness distribution according to claim 4, wherein: the three-dimensional modeling of the non-swept blade (3) in the S1 adopts a three-dimensional modeling mode of independently modeling and combining the non-swept blade tip (31) and the non-swept blade root (32) with spanwise thickness distribution.
6. The method for forming a wedge diffuser with a radial-span Γ thickness distribution according to claim 5, wherein: the blade profile of the tip part (31) of the non-swept blade (3) and the blade profile of the root part (32) of the non-swept blade adopt a modeling mode of camber line, suction surface thickness distribution and pressure surface thickness distribution;
the camber line (313) of the blade tip of the swept-back-free blade (3) is the same as the camber line (323) of the blade root;
The thickness distribution of the blade root pressure surface (321), the blade root suction surface (322) and the blade tip pressure surface (311) of the sweepless blade (3) is the same;
the thickness TTLS3 at the front edge of the suction surface (312) of the blade tip of the non-sweepback blade (3) is the same as the thickness THLS at the front edge of the suction surface (322) of the blade root of the non-sweepback blade (32), the thickness TTTS at the tail edge of the suction surface (312) of the blade tip is larger than the thickness THTS3 at the tail edge of the suction surface (322) of the blade root, and the value range is TTTS/THTS 3=1.4-2.0.
7. The method for forming a wedge diffuser with a radial-span Γ thickness distribution according to claim 5, wherein: in the spreading thickness distribution, the suction surface spreading thickness distribution of the tail edge of the blade tip and the tail edge of the blade root is controlled, a distribution curve is described by adopting a fourth-order Bezier curve, and a parameter equation of coordinates P [ T (T), H (T) ] of any point on the curve is as follows:
Wherein T (T) is a thickness value, H (T) is a relative spanwise position, T is an independent variable ;(T0,H0)、(T1,H1)、(T2,H2)、(T3,H3)、(T4,H4) of a parameter equation, and is coordinates of fourth-order bezier curve control points P0 to P4 respectively, wherein P0 (T 0,H0) is a root thickness control point of a suction surface of a blade trailing edge, and P4 (T 4,H4) is a tip thickness control point of the suction surface of the blade trailing edge, namely, T 4＝TTTS3,H4 =1; p0 to P4 are uniformly distributed in the spreading direction, and the thickness coordinates of P0 to P3 are equal.
8. The method for forming a wedge diffuser with a radial-span Γ thickness distribution according to claim 4, wherein: and S2, utilizing the circumferential rotation of the trimming line to form a trimming curved surface, and trimming the part of the blade exceeding the trimming curved surface.
9. The method of forming a vane spanwise Γ thickness distribution wedge diffuser of claim 8, wherein: the trimming line is described by a third-order Bezier curve, and the parameter equation of any point coordinate Q [ R (n), H (n) ] on the curve is as follows:
R (n) is a radial coordinate, H (n) is a relative spanwise position, and n is an independent variable of a parameter equation; (R 0,H0)、(R1,H1)、(R2,H2) is the coordinates of curve control points Q0, Q1 and Q2 respectively; wherein Q0 (R 0,H0) is the arc radius control point where the root of the tail edge of the blade is positioned; q2 (R 2,H2) is the arc radius control point where the tail edge tip of the blade is located.
CN202410524652.9A 2024-04-29 2024-04-29 Auxiliary power device for aircraft, blade spanwise gamma-shaped thickness distribution wedge-shaped diffuser and forming method thereof Active CN118088496B (en)

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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105736457A (en) * 2016-03-10 2016-07-06 中国航空动力机械研究所 Centrifugal compressor
CN107303951A (en) * 2016-04-22 2017-10-31 哈米尔顿森德斯特兰德公司 Utilize the environmental control system of enhanced compressor

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5766595B2 (en) * 2011-12-15 2015-08-19 三菱重工業株式会社 Centrifugal turbomachine
CN113464497B (en) * 2021-06-24 2024-09-20 珠海格力电器股份有限公司 Diffuser, compressor and air cycle machine

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105736457A (en) * 2016-03-10 2016-07-06 中国航空动力机械研究所 Centrifugal compressor
CN107303951A (en) * 2016-04-22 2017-10-31 哈米尔顿森德斯特兰德公司 Utilize the environmental control system of enhanced compressor

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