A design method for integrated meridian flow passage of axial exhaust oblique flow compressor

Abstract

The invention discloses an integrated meridian flow channel design method for an axial exhaust oblique flow compressor, which relates to the field of compressor design, and comprises: step 1: obtaining given parameters, calculating and obtaining calculated parameters based on the given parameters, obtaining design parameters based on the given parameters and the calculated parameters, and determining an average cross-section auxiliary line of an impeller flow channel based on the design parameters; step 2: determining an impeller meridian flow channel profile based on the design parameters, the impeller meridian flow channel profile comprising: an impeller cover side profile and an impeller disk side profile; step 3: determining a diffuser meridian flow channel profile based on the design parameters, the diffuser meridian flow channel profile comprising: a diffuser cover side profile and a diffuser disk side profile; step 4: rotating 360 degrees along a rotation axis based on the impeller meridian flow channel profile and the diffuser meridian flow channel profile to obtain a wheel cover surface and a wheel disk surface of the entire compressor; the design process of the method is simple and efficient, the impeller and the diffuser have good matching, and the overall performance is high.

Description

Technical Field

[0001] The present invention relates to the field of compressor design, and in particular to a method for designing an integrated meridian flow passage of an axial exhaust oblique flow compressor. Background Art

[0002] The compressor is one of the three major components of the core of an aircraft engine. The compressor generally includes an impeller and a diffuser. According to the type of impeller, it can be divided into a centrifugal compressor, an axial flow compressor, and an oblique flow compressor. From the structure of the meridian plane and the exhaust form, the impeller of the centrifugal compressor is radial exhaust, that is, the meridian inclination angle Ф2 of the impeller outlet is equal to 90°; the impeller of the oblique flow compressor is oblique exhaust, that is, the meridian inclination angle Ф2 of the impeller outlet is between 0° and 90°; the impeller of the axial flow compressor is axial exhaust, that is, the meridian inclination angle Ф2 of the impeller outlet is equal to 0°; where Ф2 is defined as the angle between the outlet airflow direction of the impeller meridian plane and the axial direction. The outlet of the oblique flow impeller of the oblique flow compressor is oblique exhaust, so it usually needs to be turned to the radial direction or axial direction through the diffuser to be discharged, and then enter other downstream components. If the oblique flow impeller turns to radial exhaust, the outlet of the oblique flow impeller is generally connected to a radial diffuser (i.e., a diffuser in which the angle between the side profile of the diffuser disk and the axial direction is 90°), and the airflow direction at the diffuser outlet is finally radial; if the oblique flow impeller turns to axial exhaust, the outlet of the oblique flow impeller is generally connected to an oblique diffuser (i.e., a diffuser in which the angle between the side profile of the diffuser disk and the axial direction is between 0° and 90°), and the oblique diffuser is further connected to an axial diffuser (i.e., a diffuser in which the angle between the side profile of the diffuser disk and the axial direction is 0°) through a bend, and the airflow direction at the outlet of the axial diffuser is finally axial.

[0003] The inventor previously proposed a meridian flow channel design method that is universal for oblique flow / centrifugal impellers (see Chinese invention patent number: ZL202010851179.7, authorization announcement date: 2022-12-09), which uses straight lines and arcs to construct the impeller meridian flow channel profile, so that the impeller has better aerodynamic performance and machinability. However, this design method is mainly used for the meridian flow channel design of radial exhaust oblique flow / centrifugal impellers, that is, the outlet of the oblique flow impeller / centrifugal impeller is connected to the radial diffuser, and it does not have the function of carrying out the meridian flow channel design of the axial exhaust oblique flow compressor, and the adjustment ability of the wheel cover side profile is limited.

[0004] Small frontal area, single-stage high pressure ratio, compactness and high performance are the inevitable trends in the development of small and medium-sized aircraft engines, and the large flow coefficient diagonal flow compressor is one of the efficient configurations to achieve this goal. However, up to now, there is no perfect and standard design system for aviation diagonal flow compressors, and most diagonal flow compressor designs still rely on the design method of centrifugal compressors. Meridian flow design is an important link in the compressor design process, and its design results have a significant impact on the aerodynamic performance and machinability of the compressor. In particular, the diagonal flow impeller outlet inclination angle design range of the diagonal flow compressor is relatively wide, which brings difficulties to the efficient matching design of the downstream diffuser. The use of axial exhaust is an inevitable requirement for the design of small and medium-sized aircraft engine compressors. The combined diffuser design of "diagonal diffuser + axial diffuser" can better adapt to the exhaust characteristics of the diagonal flow impeller, significantly reduce the frontal area of ​​the compressor, and improve the uniformity of the flow field inside and at the outlet of the diffuser, which has great advantages in improving the overall performance of the engine. In existing literature and design cases, the selection of design parameters for the meridional flow duct of an inclined flow compressor is highly dependent on the experience of designers. There are no fixed design criteria, and there is a lack of a parametric, simple, and adaptively matched impeller and diffuser integrated meridional flow duct design method for an inclined flow compressor. Summary of the invention

[0005] The purpose of the present invention is to provide an integrated meridian flow duct design method for an axial exhaust oblique flow compressor. The method has the function of carrying out the meridian flow duct design of an axial exhaust oblique flow compressor, can have a good adjustment ability for the side profile of the oblique flow impeller cover, the design process is simple and the design experience requirement is low.

[0006] To achieve the above-mentioned object of the invention, the present invention provides a method for designing an integrated meridian flow passage of an axial exhaust oblique flow compressor, the method comprising:

[0007] A method for designing an integrated meridian flow passage of an axial exhaust oblique flow compressor, the method comprising:

[0008] Step 1: Obtain given parameters, calculate and obtain calculated parameters based on the given parameters, obtain design parameters based on the given parameters and the calculated parameters, and determine the average cross-sectional auxiliary line of the impeller flow channel based on the design parameters. The average cross-sectional auxiliary line of the impeller flow channel includes arc segments. , where the arc segment , arc segment The center of the circle O M and arc segments Arc radius R M Through the end point M1 at the root mean square radius of the impeller inlet, the end point M2 at the root mean square radius of the impeller outlet, and the auxiliary end point M 3p The three-point combination is determined;

[0009] Step 2: Determine the impeller meridian flow path profile based on the design parameters. The impeller meridian flow path profile includes: the impeller cover side profile and the impeller disk side profile; the impeller cover side profile includes a straight line segment and arc segments , where the arc segment , arc segment The center of the circle O S and arc segments Arc radius R S Through the middle end point S on the wheel cover side 15 , impeller outlet cover side end point S2 and arc segment The corresponding center angle combination is determined; the straight line segment Through the impeller inlet cover side end point S1 and the cover side middle end point S 15 The connecting line is determined; the side profile of the impeller disk includes the arc segment , where the arc segment , arc segment The center of the circle O H and arc segments Arc radius R H Through the impeller inlet disk side end point H1, the impeller outlet disk side end point H2 and the auxiliary end point H 3p The three-point combination is determined;

[0010] Step 3: Determine the diffuser meridian flow path profile based on the design parameters. The diffuser meridian flow path profile includes: diffuser cover side profile and diffuser disk side profile; diffuser cover side profile includes: arc segment , straight line segment , arc segment and straight line segments , where the arc segment Through the center O S , Arc radius R S , the impeller outlet wheel cover side end point S2 and the diffuser cover side second end point S3 are determined by combination; the straight line segment Determined by connecting the second end point S3 on the diffuser cover side and the third end point S4 on the diffuser cover side; arc segment , arc segment The center of the circle O SU and arc segments Arc radius R SU Through the third end point S4 on the diffuser cover side and the fourth end point S 45 And arc segments The corresponding center angle combination is determined; the straight line segment Through the fourth end point S on the diffuser cover side 45The diffuser disc side profile includes the straight line segment , arc segment and straight line segments , where the straight line segment Determined by the line connecting the end point H2 on the impeller outlet disk side and the third end point H4 on the diffuser disk side; the arc segment , arc segment The center of the circle O HU and arc segments Arc radius R HU Through the third end point H4 on the diffuser disk side and the fourth end point H 45 And arc segments The corresponding center angle combination is determined; the straight line segment Through the diffuser disk side fourth end point H 45 It is determined by connecting the end point H5 on the outlet disk side of the axial diffuser;

[0011] Step 4: Based on the impeller meridian flow channel profile and the diffuser meridian flow channel profile, rotate 360 ​​degrees along the rotation axis to obtain the wheel cover surface and wheel disk surface of the entire compressor.

[0012] One or more technical solutions provided by the present invention have at least the following technical effects or advantages:

[0013] (1) The structural elements of the meridian flow channel profile of the inclined flow impeller and bladeless diffuser designed by this method are all straight lines and arcs. The processing method of this type of line is simple and the technology is mature, so it has good machinability; most of the parameters given in the meridian flow channel design are derived from the one-dimensional design results of the compressor, and a small part is additional specified control parameters. The design parameters are inherently related and constrained, so fewer parameters need to be manually specified empirically, and the design process is relatively simple as a whole.

[0014] (2) Different from the existing design method with a fixed impeller cover side configuration, this method adds a new impeller meridian line design control variable - the impeller outlet shroud side meridian inclination angle Ф 2t , the impeller cover side profile can be further adjusted to better adjust the impeller flow capacity, and this parameter is geometrically associated with the diffuser profile design parameters, which can make the impeller cover side profile and the oblique diffuser cover side profile smoothly transition, which is beneficial to the design of the meridian flow channel of the axial exhaust oblique flow compressor; when Ф 2t When the value is taken as the minimum, the impeller cover profile can be designed as a pure arc line.

[0015] (3) This method adjusts the meridian inclination angle Ф of the impeller outlet disc side 2h, the inclination angle of the oblique diffuser can be controlled; the meridian flow channel profiles of the oblique diffuser and the axial diffuser are highly matched with the profiles of the oblique flow impeller, which can realize the integrated meridian flow channel design of the oblique flow compressor with oblique flow impeller + oblique diffuser + axial diffuser. The compressor impeller and diffuser have small losses and the overall performance is high.

[0016] (4) This method can quickly generate an efficient meridional configuration by controlling only a small number of one-dimensional design parameters. It has good adaptability to the meridional flow channel design of inclined flow impellers (including centrifugal impellers) with outlet meridional inclination angles of 50°~90° and axial exhaust bladeless diffusers. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of the present invention, and do not constitute a limitation on the embodiments of the present invention;

[0018] Figure 1 It is a schematic diagram of the endpoints, center and radius of the median line of the meridian flow channel of the present invention;

[0019] Figure 2 A schematic diagram for defining given parameters designed in this method;

[0020] Figure 3 It is a schematic side view of an impeller + diffuser of a specific embodiment of the present invention;

[0021] Figure 4 The following are the meridian inclination angles of different impeller outlet shroud sides according to the specific embodiments of the present invention: 2t Schematic diagram of the effect of the value on the side profile of the impeller cover and the diffuser cover, where Ф 2t The value of 53.9° is the minimum value, at which the length of the straight line segment in the impeller cover side profile is zero;

[0022] Figure 5 It is a schematic diagram of the total pressure ratio and polytropic efficiency of the impeller in the impeller performance curve of a specific embodiment of the present invention;

[0023] Figure 6 It is a schematic diagram comparing the distribution of total pressure loss coefficients of an axial exhaust diffuser and a radial exhaust diffuser in a diffuser loss curve of a specific embodiment of the present invention;

[0024] Figure 7 It is a schematic diagram of the structure of the meridian flow channel of the present invention;

[0025] Figure 8 It is a schematic diagram of a flow chart of an integrated meridian flow passage design method for an axial exhaust oblique flow compressor;

[0026] The meanings of the numbers in the accompanying drawings are:

[0027] 1. Blade leading edge; 2. Straight line segment of impeller cover side profile; 3. Arc segment of impeller cover side profile; 4. Arc segment of oblique bladeless diffuser cover side profile; 5. Straight line segment of oblique bladeless diffuser cover side profile; 6. Arc segment of axial bladeless diffuser cover side profile; 7. Straight line segment of axial bladeless diffuser cover side profile; 8. Straight line segment of axial bladeless diffuser disk side profile; 9. Arc segment of axial bladeless diffuser disk side profile; 10. Straight line segment of oblique bladeless diffuser disk side profile; 11. Blade trailing edge; 12. Arc segment of impeller disk side profile; 13. Impeller root mean square blade height section auxiliary line; 14. Oblique flow impeller; 15. Oblique bladeless diffuser; 16. Axial bladeless diffuser;

[0028] The meanings of the symbols in the accompanying drawings are:

[0029] O M , O S , O H , O SU and O HU They are: the center of the arc segment of the impeller root mean square blade height section auxiliary line, the center of the arc segment of the impeller cover side profile line, the center of the arc segment of the impeller disk side profile line, the center of the arc segment of the axial bladeless diffuser cover side profile line, and the center of the arc segment of the axial bladeless diffuser disk side profile line;

[0030] S1, S 15 , S2, S3, S4, S 45 and S5 are respectively: an end point on the impeller inlet cover side, an intermediate end point on the impeller cover side, an end point on the impeller outlet cover side, a second end point on the diffuser cover side, a third end point on the diffuser cover side, a fourth end point on the diffuser cover side, and an end point on the axial diffuser outlet cover side;

[0031] M1, M2, M 3p and H 3p They are: the end point at the root mean square radius of the impeller inlet, the end point at the root mean square radius of the impeller outlet, the auxiliary end point of the circular arc segment of the root mean square blade height section, and the auxiliary end point of the circular arc segment on the side of the impeller disk;

[0032] H1, H2, H4, H 45 and H5 are respectively: the end point on the impeller inlet disk side, the end point on the impeller outlet disk side, the third end point on the diffuser disk side, the fourth end point on the diffuser disk side, and the end point on the axial diffuser outlet disk side;

[0033] R M , R S , R H , R SU and R HUThey are respectively the arc radius of the impeller root mean square blade height section auxiliary line arc segment, the arc radius of the impeller cover side profile arc segment, the arc radius of the impeller disk side profile arc segment, the arc radius of the axial bladeless diffuser cover side profile arc segment, and the arc radius of the axial bladeless diffuser disk side profile arc segment, in mm;

[0034] R 1t , R 1rms and R 1h They are the radii of the impeller inlet shroud side, the impeller inlet RMS blade height section, and the end point of the impeller inlet disk side, in mm.

[0035] R 2t , R 2rms and R 2h They are respectively the radius of the impeller outlet shroud side, the impeller outlet RMS blade height section, and the end point of the impeller outlet disc side, in mm;

[0036] B 2——impeller outlet width, in mm; Ф2——impeller outlet meridian inclination angle, in degrees; Ф 2t —— Meridian inclination angle of impeller outlet shroud side, in degrees; Ф 2h ——meridian inclination angle of impeller outlet disc side, in degrees; R 3p ——Auxiliary endpoint M 3p and auxiliary endpoint H 3p The radius (ordinate), in mm; ΔZ3 - auxiliary endpoint H 3p Axial offset, in mm; B 4——Width of the oblique diffuser outlet, in mm; R 4av ——The radius of the midpoint of the outlet width of the oblique diffuser (ordinate), in mm; B 5——Axial diffuser outlet width, in mm; R 5av ——The radius of the midpoint of the axial diffuser outlet width (ordinate), in mm; R For radial direction, Z For the axial direction. DETAILED DESCRIPTION

[0037] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0038] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those within the scope of this description. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0039] Embodiment 1;

[0040] Please refer to Figure 8 , Figure 8 This is a flow chart of an integrated meridian flow channel design method for an axial exhaust oblique flow compressor. Please refer to Figure 1-Figure 2 , Figure 1 This is a schematic diagram of the endpoints, center and radius of the meridian flow channel of the present invention. Figure 2 Schematic diagram of the definition of given design parameters in the present invention; the present invention provides an integrated meridian flow channel design method for an axial exhaust oblique flow compressor, comprising the following steps:

[0041] (1) Obtain given parameters, calculate and obtain calculated parameters based on the given parameters, obtain design parameters based on the given parameters and the calculated parameters, and determine the average cross-section auxiliary line of the impeller flow channel based on the design parameters:

[0042] The average cross-section auxiliary line of the impeller flow channel is composed of arc segments The arc segment and its center O M and the arc radius R M Through the end point M1 at the root mean square radius of the impeller inlet, the end point M2 at the root mean square radius of the impeller outlet, and the auxiliary end point M 3p Three-point combination determination; arc segment The center of the circle O M The horizontal coordinate of is the same as the horizontal coordinate of the end point M1 at the impeller inlet root mean square radius; The center of the circle O M The vertical coordinate and auxiliary endpoint M 3p The ordinates of the arc segments are the same; The angle value corresponding to the central angle is equal to the impeller outlet meridian inclination angle Ф2;

[0043] (2) Determine the impeller meridian flow path profile based on design parameters:

[0044] The impeller cover side profile is composed of straight line segments and arc segments The arc segment and its center O S and the arc radius R S Through the middle end point S on the wheel cover side 15 , impeller outlet cover side end point S2 and arc segment The corresponding center angle combination is determined, and the arc segment The corresponding central angle is equal to the meridian inclination angle Ф of the impeller outlet wheel cover side 2t ; Arc segment The center of the circle O S The horizontal coordinate of the wheel cover side middle end point S 15 The horizontal coordinates are the same; the middle end point S on the wheel cover side 15 The ordinate of is the same as the ordinate of the end point S1 on the impeller inlet wheel cover side; the straight line segment passes through the end point S1 on the impeller inlet wheel cover side and the middle end point S 15 Connection confirmed;

[0045] The side profile of the impeller disk is composed of arc segments The arc segment and its center O H and the arc radius R H Through the impeller inlet disk side end point H1, the impeller outlet disk side end point H2 and the auxiliary end point H 3p The three-point combination determines the horizontal coordinate of the end point H1 on the impeller inlet disk side and the end point S1 on the impeller inlet cover side. 3p The vertical coordinate and arc segment The center of the circle O M The vertical coordinates are the same;

[0046] Center O M The four points of the impeller inlet cover side endpoint S1, the impeller inlet root mean square radius endpoint M1 and the impeller inlet disk side endpoint H1 are on a straight line; the center of the circle O M The four points S2, the end point S2 at the impeller outlet wheel cover side, the end point M2 at the impeller outlet root mean square radius and the end point H2 at the impeller outlet wheel disc side are on a straight line; the center O M , auxiliary endpoint M 3p and auxiliary endpoint H 3p Three points are in a straight line;

[0047] (3) Determine the diffuser meridian flow profile based on design parameters:

[0048] The side profile of the diffuser cover is composed of arc segments , straight line segment , arc segment and straight line segments The arc segment Through the center O S , Arc radius R S , the impeller outlet wheel cover side end point S2 and the diffuser cover side second end point S3 are determined by combination; the straight line segment Determined by connecting the second end point S3 on the diffuser cover side and the third end point S4 on the diffuser cover side; arc segment and its center O SU , Arc radius R SU Through the third end point S4 on the diffuser cover side and the fourth end point S 45 And arc segments The corresponding center angle combination is determined; the straight line segment Through the fourth end point S on the diffuser cover side 45 It is determined by connecting the end point S5 on the outlet cover side of the axial diffuser;

[0049] The diffuser disc side profile is composed of straight line segments , arc segment and straight line segments The straight line segment The straight line segment is determined by connecting the end point H2 on the impeller outlet disk side and the third end point H4 on the diffuser disk side. The angle with the axial direction is equal to the meridian inclination angle Ф of the impeller outlet wheel side 2h ; Arc segment and its center O HU and the arc radius R HU Through the third end point H4 on the diffuser disk side and the fourth end point H 45 And arc segments The corresponding center angle combination is determined; the straight line segment Through the diffuser disk side fourth end point H 45 It is determined by connecting the end point H5 on the outlet disk side of the axial diffuser;

[0050] (4) The impeller profile obtained in step (2) and the diffuser profile obtained in step (3) are rotated 360 degrees along the rotation axis to obtain the wheel cover surface and wheel disk surface of the entire compressor.

[0051] Among them, in the embodiment of the present invention, in steps (1) to (3), the following parameter values ​​are given during design, that is, the given parameters include: the ordinate of the end point S1 on the impeller inlet shroud side is R 1t ; The ordinate of the end point H1 on the impeller inlet disk side is R 1h ; The ordinate of the end point M2 at the impeller outlet root mean square radius is R 2rms ; Impeller outlet width (i.e. straight line segment length) value is B 2; the meridian inclination angle of the impeller outlet is Ф2; the meridian inclination angle of the impeller outlet wheel cover side is Ф 2t ; The meridian inclination angle of the impeller outlet disc side is Ф 2h ; Auxiliary endpoint H3p The axial offset is ΔZ3; the width of the diagonal diffuser outlet (i.e. the straight line segment Length) is B 4; The ordinate of the midpoint of the diagonal diffuser outlet width is R 4av ; Axial diffuser outlet width value (i.e. straight line segment Length) is B 5; The ordinate of the midpoint of the axial diffuser outlet width is R 5av ;

[0052] The following parameter values ​​are obtained by calculation, that is, the calculation parameters include:

[0053] The ordinate of the end point M1 at the impeller inlet root mean square radius is R 1rms , the calculation method is: ;

[0054] The ordinate of the end point S2 on the impeller outlet cover side is R 2t , the calculation method is:

[0055] ;

[0056] The ordinate of the end point H2 on the impeller outlet disk side is R 2h , the calculation method is:

[0057] ;

[0058] Auxiliary endpoint M 3p and auxiliary endpoint H 3p The vertical coordinates are R 3p , the calculation method is:

[0059] .

[0060] In this embodiment of the present invention, in step (2), the auxiliary endpoint M 3p With auxiliary endpoint H 3p The axial distance between them is equal to 0.5 B 2 R 2rms / R 3p +ΔZ3; in step (3), the third endpoint S4 on the diffuser cover side, the third endpoint H4 on the diffuser disk side and the center O HU On a straight line, the straight line segment Perpendicular to a line segment ; Diffuser disk side fourth end point H 45 The horizontal coordinate and the center OHU The horizontal coordinates are the same; the fourth end point H on the diffuser disk side 45 The ordinate of is the same as that of the endpoint H5 on the outlet disk side of the axial diffuser; The corresponding central angle is equal to the meridian inclination angle of the impeller outlet disc side. 2h ; Straight line segment With arc segment Tangent to the second end point S3 on the diffuser cover side; straight line segment Perpendicular to a line segment ; Diffuser cover side fourth end point S 45 The horizontal coordinate and the center O SU The horizontal coordinates are the same; the fourth end point S on the diffuser cover side 45 The ordinate of is the same as the ordinate of the end point S5 on the axial diffuser outlet cover side; Corresponding central angle and arc segment The corresponding central angles are equal.

[0061] Among them, in the embodiment of the present invention, when the impeller outlet meridian inclination angle Ф2 is equal to 90°, the impeller is a centrifugal impeller; when 0°<impeller outlet meridian inclination angle Ф2<90°, the impeller is an oblique flow impeller.

[0062] A further improvement of the present invention is that the impeller outlet wheel cover side meridian inclination angle Φ 2t There is a minimum value, when the impeller outlet shroud side meridian inclination angle Ф 2t When the straight line segment is at its minimum value, Length is zero; arc segment The corresponding central angle should not be less than the meridian inclination angle Ф of the impeller outlet wheel cover side 2t By adjusting the design parameter, the impeller outlet shroud side meridian inclination angle Ф 2t Or the meridian inclination angle of the impeller outlet disc side Ф 2h To meet this condition; by 3p The axial offset ΔZ3 is set to a positive value or a negative value to adjust the side profile of the impeller disk to achieve the purpose of adjusting the flow capacity of the meridian flow channel.

[0063] See also Figure 7In the meridian flow channel of the specific embodiment constructed by the present invention, the impeller is an oblique flow impeller 14 with axial air intake, and the air is discharged axially after being guided by the oblique bladeless diffuser 15 and the axial bladeless diffuser 16. The impeller root mean square blade height section auxiliary line 13 can be regarded as the average flow trajectory in the meridian flow channel. The cover side profile of the meridian flow channel is composed of the impeller cover side profile straight line segment 2, the impeller cover side profile arc segment 3, the oblique bladeless diffuser cover side profile arc segment 4, the oblique bladeless diffuser cover side profile straight line segment 5, the axial bladeless diffuser cover side profile arc segment 6, and the axial bladeless diffuser cover side profile straight line segment 7. The disk side profile of the meridian flow channel is composed of the impeller disk side profile arc segment 12, the oblique bladeless diffuser disk side profile straight line segment 10, the axial bladeless diffuser disk side profile arc segment 9, and the axial bladeless diffuser disk side profile straight line segment 8. When designing the impeller blades, a straight blade leading edge 1 and a straight blade trailing edge 11 are used. The following is an example of the design of a meridian flow passage of a certain oblique flow compressor.

[0064] (1) Determine the input parameters through the one-dimensional design method of the inclined flow impeller.

[0065] Input parameters include: Impeller inlet shroud radius R 1t =649mm, wheel radius R 1h =151mm, impeller outlet root mean square radius R 2rms =865mm, outlet width B 2 = 228mm, outlet meridian inclination angle Ф2 = 65°, impeller outlet wheel cover side meridian inclination angle Ф 2t =60°, impeller outlet disc side meridian inclination angle Ф 2h =75°, auxiliary endpoint H 3p Axial offset ΔZ3=0, oblique diffuser outlet width B 4 = 134 mm, the vertical coordinate of the midpoint of the diagonal diffuser outlet width R 4av =1471mm, axial diffuser outlet width B 5=123mm, the ordinate of the midpoint of the axial diffuser outlet width is R 5av =1600mm.

[0066] (2) Determine the endpoint parameters of the average section auxiliary line.

[0067] The radius (ordinate) of the end point M1 at the impeller inlet root mean square radius is R 1rms =471.17mm;

[0068] Auxiliary endpoint M 3p and auxiliary endpoint H 3pThe vertical coordinate is R 3p =1153.27mm.

[0069] (3) Determine the endpoint parameters of the impeller meridian flow channel profile.

[0070] Middle end point S of wheel cover side 15 The radius (ordinate) is 649mm;

[0071] The radius (ordinate) of the end point S2 on the impeller outlet cover side is R 2t =911.84mm;

[0072] The radius (ordinate) of the end point H2 on the impeller outlet disk side is R 2h =815.48mm.

[0073] (4) Determine the endpoint parameters of the impeller meridian flow channel profile.

[0074] The radius (ordinate) of the second end point S3 on the diffuser cover side is 969.92 mm;

[0075] The radius (ordinate) of the third end point S4 on the diffuser cover side is 1487.86 mm;

[0076] Diffuser cover side fourth end point S 45 The radius (ordinate) is 1661.87mm;

[0077] The radius (ordinate) of the end point S5 on the axial diffuser outlet cover side is 1661.87 mm;

[0078] The radius (ordinate) of the third end point H4 on the diffuser disk side is 1453.14 mm;

[0079] Diffuser disk side fourth end point H 45 The radius (ordinate) is 1538.63mm;

[0080] The radius (ordinate) of the end point H5 on the outlet disk side of the axial diffuser is 1538.63 mm;

[0081] Arc segment The corresponding central angle is 67.08°, which is larger than the meridian inclination angle Ф of the impeller outlet wheel cover side 2t =60°. Taking the average position of the RMS section at the impeller outlet as the zero point of the horizontal coordinate (Z=0), the calculation parameters of each arc segment are shown in Table 1, and the coordinates of the compressor cover disc profile are shown in Table 2.

[0082] Table 1 Calculation parameters of each arc segment

[0083]

[0084] Table 2 Coordinates of wheel cover and wheel disc profile (unit: mm)

[0085]

[0086] (5) The cover side profile and the disk side profile obtained in the above steps are rotated 360° along the rotation axis to obtain the wheel cover surface and the wheel disk surface. The three-dimensional modeling of the oblique flow compressor using the meridian flow profile is as follows: Figure 3 As shown, Figure 3 It is a schematic side view of an impeller+diffuser according to a specific embodiment of the present invention.

[0087] Figure 4 The following are the meridian inclination angles of different impeller outlet shroud sides according to the specific embodiments of the present invention: 2t Schematic diagram showing the effect of the value on the side profile of the impeller cover and the diffuser cover. Figure 4 As shown in the figure, if the impeller flow capacity needs to be increased, the impeller outlet shroud side meridian inclination angle Ф can be reduced 2t Value, in this case Ф 2t The minimum value of is 53.9°, at which point the impeller cover side profile only contains a circular arc segment; conversely, if the impeller flow capacity needs to be reduced, the impeller outlet shroud side meridian inclination angle Ф can be increased. 2t value, thereby realizing local adjustment of the impeller flow capacity and adaptively adjusting the configuration of the diffuser.

[0088] Given that the impeller surface roughness is 3.2μm, a numerical simulation is performed on the axial exhaust oblique flow compressor. Through the simulation, it can be found that although there is a local low-speed area on the impeller outlet shroud side, the flow in the matching oblique diffuser and axial diffuser is relatively uniform. Figure 5 The total pressure ratio and variable efficiency performance of the impeller at the design speed are numerically predicted. From the results, it can be seen that the surge margin of the impeller design point is about 9%, the design point efficiency is about 91%, and the high efficiency range is wide; the radial exhaust diffuser and the axial exhaust diffuser with the same outlet size are matched for the diagonal flow impeller, and the total pressure loss coefficient comparison is obtained. Figure 6 As shown, it can be seen that the axial exhaust diffuser of the oblique flow compressor designed by the present invention has a lower loss level, which shows the effectiveness and efficiency of the design method.

[0089] The meridian flow channel formed by this method is composed of simple elements such as straight lines and arcs, and has good machinability. It can be used at different impeller outlet meridian inclination angles Ф2, different diffuser inclination angles (i.e., impeller outlet disk side meridian inclination angle Ф 2h ) and other parameters, the corresponding high-efficiency oblique flow meridian configuration is quickly generated. This configuration has small flow loss and can meet the aerodynamic design requirements of the oblique flow compressor.

[0090] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0091] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for designing an integrated meridian flow passage for an axial exhaust oblique flow compressor, characterized in that: The method comprises: Step 1: Obtain given parameters, calculate and obtain calculated parameters based on the given parameters, obtain design parameters based on the given parameters and the calculated parameters, and determine the average cross-sectional auxiliary line of the impeller flow channel based on the design parameters. The average cross-sectional auxiliary line of the impeller flow channel includes arc segments. , where the arc segment , arc segment The center of the circle O M and arc segments The arc radius R M Through the end point M1 at the root mean square radius of the impeller inlet, the end point M2 at the root mean square radius of the impeller outlet, and the auxiliary end point M 3p The three-point combination is determined; Step 2: Determine the impeller meridian flow path profile based on the design parameters. The impeller meridian flow path profile includes: the impeller cover side profile and the impeller disk side profile; the impeller cover side profile includes a straight line segment and arc segments , where the arc segment , arc segment The center of the circle O S and arc segments The arc radius R S Through the middle end point S on the wheel cover side 15 , impeller outlet wheel cover side end point S2 and arc segment The corresponding center angle combination is determined; the straight line segment Through the impeller inlet cover side end point S1 and the cover side middle end point S 15 The connecting line is determined; the side profile of the impeller disk includes the arc segment , where the arc segment , arc segment The center of the circle O H and arc segments The arc radius R H Through the impeller inlet disk side end point H1, the impeller outlet disk side end point H2 and the auxiliary end point H 3p The three-point combination is determined; Step 3: Determine the diffuser meridian flow path profile based on the design parameters. The diffuser meridian flow path profile includes: diffuser cover side profile and diffuser disk side profile; diffuser cover side profile includes: arc segment , straight line segment , arc segment and straight line segments , where the arc segment Through the center O S , Arc radius R S , the impeller outlet wheel cover side end point S2 and the diffuser cover side second end point S3 are determined by combination; the straight line segment Determined by connecting the second end point S3 on the diffuser cover side and the third end point S4 on the diffuser cover side; arc segment , arc segment The center of the circle O SU and arc segments The arc radius R SU Through the third end point S4 on the diffuser cover side and the fourth end point S 45 And arc segments The corresponding center angle combination is determined; the straight line segment Through the fourth end point S on the diffuser cover side 45 The diffuser disc side profile includes the straight line segment , arc segment and straight line segments , where the straight line segment Determined by the line connecting the end point H2 on the impeller outlet disk side and the third end point H4 on the diffuser disk side; the arc segment , arc segment The center of the circle O HU and arc segments The arc radius R HU Through the third end point H4 on the diffuser disk side and the fourth end point H 45 And arc segments The corresponding center angle combination is determined; the straight line segment Through the diffuser disk side fourth end point H 45 It is determined by connecting the end point H5 on the outlet disk side of the axial diffuser; Step 4: Based on the impeller meridian flow channel profile and the diffuser meridian flow channel profile, rotate 360 ​​degrees along the rotation axis to obtain the wheel cover surface and wheel disk surface of the entire compressor.

2. The method for designing an integrated meridian flow passage for an axial exhaust oblique flow compressor according to claim 1, characterized in that: Center O M The horizontal coordinate of is the same as that of the end point M1 at the impeller inlet root mean square radius; the center O M The vertical coordinate and auxiliary endpoint M 3p The ordinates of the arc segments are the same; The corresponding central angle is equal to the impeller outlet meridian inclination angle Ф2.

3. The method for designing an integrated meridian flow passage for an axial exhaust oblique flow compressor according to claim 1, characterized in that: Arc segment The corresponding central angle is equal to the meridian inclination angle Ф of the impeller outlet wheel cover side 2t ; Center O S The horizontal coordinate of the wheel cover side middle end point S 15 The horizontal coordinates are the same; the middle end point S on the wheel cover side 15 The ordinate of is the same as the ordinate of the end point S1 on the impeller inlet cover side.

4. The method for designing an integrated meridian flow passage for an axial exhaust oblique flow compressor according to claim 1, characterized in that: The horizontal coordinate of the end point H1 on the impeller inlet disk side is the same as the horizontal coordinate of the end point S1 on the impeller inlet cover side; 3p The vertical coordinate and the center O M The vertical coordinates are the same.

5. The method for designing an integrated meridian flow passage for an axial exhaust oblique flow compressor according to claim 1, characterized in that: Center O M The four points of the impeller inlet cover side endpoint S1, the impeller inlet root mean square radius endpoint M1 and the impeller inlet disk side endpoint H1 are on a straight line; the center of the circle O M The four points S2, the end point S2 at the impeller outlet wheel cover side, the end point M2 at the impeller outlet root mean square radius and the end point H2 at the impeller outlet wheel disc side are on a straight line; the center O M , auxiliary endpoint M 3p and auxiliary endpoint H 3p The three points are in a straight line.

6. The method for designing an integrated meridian flow passage for an axial exhaust oblique flow compressor according to claim 1, characterized in that: Straight line segment The angle with the axial direction is equal to the meridian inclination angle Ф of the impeller outlet wheel side 2h .

7. The method for designing an integrated meridian flow passage for an axial exhaust oblique flow compressor according to claim 1, characterized in that: The given parameters are: The ordinate of the end point S1 on the impeller inlet cover side is R 1t ; The ordinate of the end point H1 on the impeller inlet disk side is R 1h ; The ordinate of the end point M2 at the impeller outlet root mean square radius is R 2rms ; Impeller outlet width straight line segment The length value is B 2; the meridian inclination angle of the impeller outlet is Ф2; the meridian inclination angle of the impeller outlet wheel cover side is Ф 2t ; The meridian inclination angle of the impeller outlet disc side is Ф 2h ; Auxiliary endpoint H 3p The axial offset is ΔZ3; the straight line segment of the oblique diffuser outlet width The length value is B 4; The ordinate of the midpoint of the diagonal diffuser outlet width is R 4av ; Axial diffuser outlet width straight section The length value is B 5; The ordinate of the midpoint of the axial diffuser outlet width is R 5av ; The calculation parameters include: the ordinate of the end point M1 at the impeller inlet root mean square radius R 1rms , the ordinate of the end point S2 on the impeller outlet shroud side R 2t , the ordinate of the end point H2 on the impeller outlet disk side R 2h , auxiliary endpoint M 3p With auxiliary endpoint H 3p The vertical coordinate R 3p , the calculation parameters are calculated as follows: ； ； ； 。 8. The method for designing an integrated meridian flow passage for an axial exhaust oblique flow compressor according to claim 7, characterized in that: Auxiliary endpoint M 3p With auxiliary endpoint H 3p The axial distance between them is equal to 0.5 B 2 R 2rms / R 3p +ΔZ3; the third endpoint S4 on the diffuser cover side, the third endpoint H4 on the diffuser disk side and the center O HU On a straight line, the straight line segment Perpendicular to a line segment ; Diffuser disk side fourth end point H 45 The horizontal coordinate and the center O HU The horizontal coordinates are the same; the fourth end point H on the diffuser disk side 45 The ordinate of is the same as that of the endpoint H5 on the outlet disk side of the axial diffuser; The corresponding central angle is equal to the meridian inclination angle Ф of the impeller outlet wheel side 2h ; Straight line segment With arc segment Tangent to the second end point S3 on the diffuser cover side; straight line segment Perpendicular to a line segment ; Diffuser cover side fourth end point S 45 The horizontal coordinate and the center O SU The horizontal coordinates are the same; the fourth end point S on the diffuser cover side 45 The ordinate of is the same as the ordinate of the end point S5 on the axial diffuser outlet cover side; Corresponding central angle and arc segment The corresponding central angles are equal.

9. The method for designing an integrated meridian flow passage for an axial exhaust oblique flow compressor according to claim 7, characterized in that: When the impeller outlet meridian inclination angle Ф2 is equal to 90°, the impeller is a centrifugal impeller; when 0°<impeller outlet meridian inclination angle Ф2<90°, the impeller is an oblique flow impeller.

10. The method for designing an integrated meridian flow passage for an axial exhaust oblique flow compressor according to claim 7, characterized in that: The method further comprises based on the auxiliary endpoint H 3p The axial offset ΔZ3 adjusts the side profile of the impeller disk; the method adjusts the design parameter impeller outlet wheel cover side meridian inclination Ф 2t Or the impeller outlet disk side meridian inclination angle Ф 2h The following designs can be realized: Impeller outlet shroud side meridian inclination angle Ф 2t There is a minimum value, when the impeller outlet shroud side meridian inclination angle Ф 2t When the straight line segment is at its minimum value, Length is zero; arc segment The corresponding central angle is greater than or equal to the meridian inclination angle Ф of the impeller outlet wheel cover side 2t .

Images