A high-speed fuel pump constant pressure impeller design method and impeller

Abstract

The application discloses a high-speed fuel pump constant-pressure impeller design method and an impeller, and has the characteristics that the method comprises the following steps: (1) judging whether the original impeller model meets the constant-pressure condition by using the flow interval difference ratio relationship; (2) if not, collecting the head H, the dynamic head H v and the potential head H p under different flows, analyzing the correlation of the dynamic head H v set and the potential head H p set with the head H set, and performing parameterized design on the geometric parameters affecting the constant-pressure effect of the impeller; and (3) performing blade profile optimization design on the impeller blades, so as to suppress the vortex generated under the small-flow working condition, regulate the dynamic head under the small-flow working condition, make the final impeller model meet the flow interval difference ratio relationship, and thus have the constant-pressure effect. The application can accurately determine the geometric size parameters, such as the outer diameter and the outlet width of the high-speed fuel pump impeller, affecting the constant-pressure effect of the impeller; meanwhile, the application can effectively reduce the axial force of the impeller, improve the pressure distribution, improve the medium flow state, reduce the flow loss, improve the oil pumping performance of the high-speed fuel pump, and improve the overall hydraulic efficiency of the pump.

Description

Technical Field

[0001] This invention relates to the field of impeller technology for high-speed fuel pumps, and specifically to a design method for a constant pressure impeller for a high-speed fuel pump and the impeller itself. Background Technology

[0002] As a crucial component of aircraft fuel supply systems, the high-speed fuel pump's function is to deliver fuel to the engine within the required flow range, enabling the engine to generate thrust. With the rapid development of aviation technology, high-speed operation has become a key development direction for fuel pumps. Aircraft fuel supply systems will operate in more complex environments, placing more stringent demands on pump design. During flight, aircraft adjust their flight attitude based on the fuel pump's flow rate, and different flight attitudes require the pump to provide a constant pressure flow. Increasing the fuel pump's speed directly affects the stability of the pump pressure, which in turn affects the stability of the aircraft system.

[0003] Traditional fuel pump impeller designs do not prioritize constant pressure design, resulting in large pressure drops and unstable HQ (head-flow rate) curves within the designed flow range. This invention, building upon traditional impeller design methods, analyzes the correlation between dynamic head and head, and potential head and head, under different flow conditions. By evaluating the correlation, it establishes relationships between dynamic head, potential head, and impeller geometric parameters. Furthermore, it optimizes the impeller structure by optimizing the blade profile to suppress vortices generated under low flow conditions, thereby controlling the dynamic head under low flow conditions and obtaining a constant pressure impeller that meets the requirements of flow segmentation. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a constant-pressure impeller design method and impeller for a high-speed fuel pump. By optimizing the constant-pressure design of the high-speed fuel pump impeller, the operating requirements of the fuel pump under high speed and complex environments can be met. By analyzing the correlation between dynamic head and head, and potential head and head under different flow conditions, the geometric dimensional parameters affecting the constant-pressure effect of the impeller, such as the outer diameter and outlet width, can be accurately determined. Simultaneously, by optimizing the airfoil design of the main and auxiliary blades, and with the intermediate flow channel between the main and auxiliary blades directly connected to the pump's rear chamber, the designed impeller can effectively reduce the impeller axial force, improve / regulate pressure distribution, improve the medium flow state, reduce flow losses, improve the oil suction / pumping performance of the high-speed fuel pump, and improve the overall hydraulic efficiency of the pump.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A method for designing a constant-pressure impeller for a high-speed fuel pump, characterized by comprising the following steps:

[0007] (1) For the original impeller model, use the ratio of flow interval differences to determine whether the constant pressure condition is met;

[0008] (2) If not satisfied, collect head H and dynamic head H under different flow rates. v Harmony and Momentum H p Based on the driving head H v Gathering, momentum rising H p The correlation analysis between the collection and the head H collection is carried out, and the geometric parameters affecting the constant pressure effect of the impeller are parametrically designed.

[0009] (3) Further optimize the blade shape of the impeller to suppress the vortex generated under low flow conditions and regulate the dynamic head under low flow conditions, so that the final impeller model satisfies the flow range difference ratio relationship and thus has a constant pressure effect.

[0010] Furthermore, the flow rate interval is segmented (the flow rate interval of the original model HQ performance curve is segmented), and the ratio of the difference between the flow rate and the head at both ends is as follows:

[0011]

[0012] Among them, head H n For dimensionless head and flow rate Q n Dimensionless flow rate;

[0013] If the above conditions are not met, proceed to the next step of adjusting the original impeller model.

[0014] Furthermore, the head H and dynamic head H were collected under different flow rates. v , momentum rise H p The data in the set is obtained from the following relation:

[0015] H p =HH v

[0016] Head H v The collection formula is:

[0017]

[0018] v1 - impeller inlet velocity, v2 - impeller outlet velocity, g - gravitational acceleration.

[0019] Furthermore, the driving lift H v Gathering, momentum rising H p Correlation analysis between the set of heads and the set of pump heads H: Person correlation coefficient was used to evaluate the dynamic head H. v Collection and lifting range H collection, momentum lifting range H p The correlation coefficients between the set and the head H set are P0 and P0 respectively.v P p The formula for calculating the Person correlation coefficient is:

[0020]

[0021] cov(X,Y) - covariance of X,Y; σ X σ Y -X, standard deviation of Y.

[0022] Furthermore, the standard for evaluating the correlation is: the larger the correlation coefficient P value, the higher the correlation; if the correlation coefficient P... v If it is large, it can be based on the formula:

[0023]

[0024] Parametric design of impeller geometry parameters; if the correlation coefficient P p If the value is large, it is based on the formula relating dynamic head and potential head:

[0025]

[0026] Parametric design of impeller geometry parameters.

[0027] Furthermore, the impeller geometric parameters include: impeller outlet diameter D2, impeller outlet width b2, number of blades z, blade inlet angle β1, blade outlet angle β2, and blade thickness s;

[0028] The impeller outlet diameter D2 and impeller outlet width b2 are calculated based on the dynamic head calculation formula:

[0029]

[0030] n - rotational speed, H d -Design head, H-Actual head under the original model design flow rate;

[0031]

[0032] β2 - blade exit angle, k2 - blade exit displacement coefficient, η v -Volume efficiency, W-Finite blade number correction factor;

[0033] Number of blades: 2 ≤ z ≤ 8;

[0034] Blade inlet angle: 10° < β1 < 35°;

[0035] Blade exit angle: 20 < β2 < 90°;

[0036] Blade thickness: 1≤s≤6mm;

[0037] Finite blade correction factor: 0.2 <W<0.5;

[0038] Furthermore, the blade exit angle β2 includes: the main blade exit angle β 21 Secondary blade exit angle β 22 , and β 21 ≥β 22 (e.g. β) 21 =β 22 ).

[0039] During design calculations, the dimensionless numerical values ​​of each parameter / unit are used for design / calculation.

[0040] A high-speed fuel pump constant pressure impeller can be designed using the above-mentioned high-speed fuel pump constant pressure impeller design method. The fuel pump is a centrifugal pump, which includes a front cover plate (1), a rear cover plate (2), blades (3), main blades (4), auxiliary blades (5), and a middle flow channel (6). Multiple blades are evenly distributed circumferentially and connected between the front cover plate and the rear cover plate. Each blade has a main blade and an auxiliary blade. The blades are roughly "Y" shaped. The profiles of the main blades and auxiliary blades have airfoil characteristics. The main blades and auxiliary blades form a middle flow channel. The radial inner ends of the main blades and auxiliary blades are connected to the common blade section. The feature is that the middle flow channel (6) penetrates the rear cover plate and is directly connected to the pump rear cavity. A connecting hole (7) is opened on the auxiliary blade. The connecting hole connects the pressure surface and the negative pressure surface of the auxiliary blade respectively. That is, the connecting hole connects the middle flow channel and the concave arc surface of the auxiliary blade respectively.

[0041] Furthermore, the concave arc surface of the main blade (4) near the secondary blade is provided with a concave portion (8) and a convex portion (9), the concave portion and the convex portion are arranged adjacent to each other, and the concave portion and the convex portion are located radially outside the connecting hole (7).

[0042] Furthermore, the recess (8) and the convex part (9) are roughly triangular in shape and roughly centrally symmetrical in shape.

[0043] Furthermore, the convex surface of the main blade (4) includes a first arc surface (41) and a second arc surface. The radius of the first arc surface is greater than the radius of the second arc surface, and the centerline of the connecting hole (7) is approximately parallel to the first arc surface. The centerline of the connecting hole approximately passes through one corner or corner endpoint of the triangle of the protrusion (9).

[0044] Furthermore, the profiles of the main blade (4) and the secondary blade (5) have airfoil characteristics, the thickness of the main blade and the secondary blade is non-equal thickness design, and the main blade and / or the secondary blade have more than 5 different thickness values.

[0045] This invention discloses a constant-pressure impeller design method and impeller for a high-speed fuel pump. By optimizing the constant-pressure design of the high-speed fuel pump impeller, it can meet the operating requirements of the fuel pump under high speed and complex environments. By analyzing the correlation between dynamic head and head, and potential head and head under different flow conditions, the geometric dimensional parameters affecting the constant-pressure effect of the impeller, such as the outer diameter and outlet width, can be accurately determined. The optimal design parameters of the impeller can be obtained accurately and efficiently to meet the design requirements. The designed constant-pressure impeller can improve the stability and reliability of the aircraft fuel system. Simultaneously, by optimizing the airfoil design of the main blades and auxiliary blades, and with the intermediate flow channel between the main blades and auxiliary blades directly connected to the pump's rear chamber, the designed impeller can effectively reduce the impeller axial force, improve / regulate pressure distribution, improve the medium flow state, reduce flow losses, improve the oil suction / pumping performance of the high-speed fuel pump, and improve the overall hydraulic efficiency of the pump. Attached Figure Description

[0046] Figure 1 This is a flowchart of the high-speed fuel pump constant pressure impeller design method of the present invention;

[0047] Figure 2 This is a three-dimensional structural diagram of the constant pressure impeller of the high-speed fuel pump of the present invention;

[0048] Figure 3 This is a side view of the constant pressure impeller structure of the high-speed fuel pump of the present invention;

[0049] Figure 4 This is a schematic diagram of the main structure of the constant pressure impeller of the high-speed fuel pump of the present invention;

[0050] Figure 5 This is a schematic diagram of the main structure of the constant pressure impeller of the high-speed fuel pump of the present invention;

[0051] Figure 6 This is a comparison diagram of the hydraulic performance of the constant pressure impeller of the high-speed fuel pump of this invention and the original impeller model;

[0052] Figure 7 The following are schematic diagrams of the original impeller structure in the prior art: (a) Schematic diagram of the original impeller one structure; (b) Schematic diagram of the original impeller two structure.

[0053] In the figure: front cover plate 1, rear cover plate 2, blade 3, main blade 4, secondary blade 5, intermediate flow channel 6, connecting hole 7, concave part 8, convex part 9, first arc surface 41. Detailed Implementation

[0054] To make the technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in a clearer and more complete manner below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only some embodiments of the present invention, and are only used to explain the present invention, not to limit the present invention. It should be noted that, for ease of description, only the parts / structures related to the present invention are shown in the accompanying drawings. Other related parts can be referred to with ordinary design. In the absence of conflict, the embodiments and technical features in the embodiments of the present invention can be combined with each other to obtain new embodiments.

[0055] Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention. Furthermore, unless otherwise defined, the technical or scientific terms used in the description of this invention should have the ordinary meaning understood by those skilled in the art.

[0056] The present invention will now be described in further detail with reference to the accompanying drawings.

[0057] like Figure 1 As shown, a method for designing a constant-pressure impeller for a high-speed fuel pump is characterized by the following steps:

[0058] (1) For the original impeller model, use the ratio of flow interval differences to determine whether the constant pressure condition is met;

[0059] (2) If not satisfied, collect head H and dynamic head H under different flow rates. v Harmony and Momentum H p Based on the driving head H v Gathering, momentum rising H p The correlation analysis between the collection and the head H collection is carried out, and the geometric parameters affecting the constant pressure effect of the impeller are parametrically designed.

[0060] (3) Then, the impeller blades are optimized to suppress the vortex generated under low flow conditions and regulate the dynamic head under low flow conditions, so that the final impeller model satisfies the flow range difference ratio relationship and thus has a constant pressure effect.

[0061] Furthermore, the flow rate interval is segmented (the flow rate interval of the original model HQ performance curve is segmented), and the ratio of the difference between the flow rate and the head at both ends is as follows:

[0062]

[0063] Among them, head H n For dimensionless head and flow rate Q n Dimensionless flow rate;

[0064] If the above conditions are not met, proceed to the next step of adjusting the original impeller model.

[0065] Furthermore, the head H and dynamic head H were collected under different flow rates. v , momentum rise H p The data in the set is obtained from the following relation:

[0066] H p =HH v

[0067] Head H v The collection formula is:

[0068]

[0069] v1 - impeller inlet velocity, v2 - impeller outlet velocity, g - gravitational acceleration.

[0070] Furthermore, the driving lift H v Gathering, momentum rising H p Correlation analysis between the set of heads and the set of pump heads H: Person correlation coefficient was used to evaluate the dynamic head H. v Collection and lifting range H collection, momentum lifting range H p The correlation coefficients between the set and the head H set are P0 and P0 respectively. v P p The formula for calculating the Person correlation coefficient is:

[0071]

[0072] cov(X,Y) - covariance of X,Y; σ X σ Y -X, standard deviation of Y.

[0073] Furthermore, the standard for evaluating the correlation is: the larger the correlation coefficient P value, the higher the correlation; if the correlation coefficient P... v If it is large, it can be based on the formula:

[0074]

[0075] Parametric design of impeller geometry parameters; if the correlation coefficient P p If the value is large, it is based on the formula relating dynamic head and potential head:

[0076]

[0077] Parametric design of impeller geometry parameters.

[0078] Furthermore, the impeller geometric parameters include: impeller outlet diameter D2, impeller outlet width b2, number of blades z, blade inlet angle β1, blade outlet angle β2, and blade thickness s;

[0079] Furthermore, the impeller outlet diameter D2 and impeller outlet width b2 are calculated based on the dynamic head calculation formula:

[0080]

[0081] n is the rotational speed, H is the rotational speed d -Design head, H-Actual head under the original model design flow rate;

[0082]

[0083] β2 - blade exit angle, k2 - blade exit displacement coefficient, η v -Volume efficiency, W-Finite blade number correction factor;

[0084] Number of blades: 2 ≤ z ≤ 8;

[0085] Blade inlet angle: 10° < β1 < 35°;

[0086] Blade exit angle: 20 < β2 < 90°;

[0087] Blade thickness: 1≤s≤6mm;

[0088] Finite blade correction factor: 0.2 <W<0.5;

[0089] Furthermore, the blade exit angle β2 includes: the main blade exit angle β 21 Secondary blade exit angle β 22 , and β 21 ≥β 22 (e.g. β) 21 =β 22 ).

[0090] During design calculations, the dimensionless numerical values ​​of each parameter / unit are used for design / calculation.

[0091] This invention discloses a constant-pressure impeller design method and impeller for a high-speed fuel pump. By optimizing the constant-pressure design of the high-speed fuel pump impeller, it can meet the operating requirements of the fuel pump under high speed and complex environments. By analyzing the correlation between dynamic head and head, and potential head and head under different flow conditions, the geometric dimensional parameters affecting the constant-pressure effect of the impeller, such as the outer diameter and outlet width, can be accurately determined. The optimal design parameters of the impeller that meet the design requirements can be obtained accurately and efficiently. The designed constant-pressure impeller can improve the stability and reliability of the aircraft fuel system.

[0092] like Figure 2-5As shown, a high-speed fuel pump constant pressure impeller can be designed using the aforementioned high-speed fuel pump constant pressure impeller design method. The fuel pump is a centrifugal pump, which includes a front cover plate 1, a rear cover plate 2, blades 3, main blades 4, auxiliary blades 5, and a central flow channel 6. Multiple blades 3 are evenly distributed circumferentially and connected between the front cover plate 1 and the rear cover plate 2. Each blade 3 has a main blade 4 and an auxiliary blade 5. The blades 3 are roughly "Y" shaped. The profiles of the main blades 4 and the auxiliary blades 5 have airfoil characteristics. The central flow channel 6 is formed between the main blades 4 and the auxiliary blades 5. The radially inner ends of the main blades 4 and the auxiliary blades 5 are connected to a common blade section. The central flow channel 6 penetrates the rear cover plate 2 and is directly connected to the pump rear cavity. A connecting hole 7 is provided on the auxiliary blade 5. The connecting hole 7 connects the pressure surface and the negative pressure surface of the auxiliary blade 5 respectively, that is, the connecting hole 7 connects the concave arc surface of the central flow channel 6 and the auxiliary blade 5 respectively.

[0093] Furthermore, the concave arc surface of the main blade 4 near the secondary blade 5 is provided with a concave portion 8 and a convex portion 9, the concave portion 8 and the convex portion 9 are arranged adjacent to each other, and the concave portion 8 and the convex portion 9 are located radially outside the connecting hole 7.

[0094] The concave part 8 and the convex part 9 are roughly triangular in structure and roughly centrally symmetrical.

[0095] The convex surface of the main blade 4 includes a first arc surface 41 and a second arc surface. The radius of the first arc surface 41 is greater than the radius of the second arc surface, and the centerline of the connecting hole 7 is roughly parallel to the first arc surface 41. The centerline of the connecting hole 7 roughly passes through one corner or corner endpoint of the triangle of the protrusion 9.

[0096] The profiles of the main blade 4 and the secondary blade 5 have airfoil characteristics. The thickness of the main blade 4 and the secondary blade 5 is non-equal, and the main blade 4 and / or the secondary blade 5 have at least 5 different thickness values.

[0097] The present invention discloses a constant pressure impeller design method and impeller for a high-speed fuel pump. By optimizing the blade shape of the main blade and the auxiliary blade, the intermediate flow channel between the main blade and the auxiliary blade is directly connected to the pump back cavity. The designed impeller can effectively reduce the axial force of the impeller, improve / regulate the pressure distribution, improve the medium flow state, reduce flow loss, improve the oil suction / pumping performance of the high-speed fuel pump, and improve the overall hydraulic efficiency of the pump.

[0098] This invention discloses a constant-pressure impeller design method and impeller for a high-speed fuel pump. By optimizing the constant-pressure design of the high-speed fuel pump impeller, it can meet the operating requirements of the fuel pump under high speed and complex environments. By analyzing the correlation between dynamic head and head, and potential head and head under different flow conditions, the geometric dimensional parameters affecting the constant-pressure effect of the impeller, such as the outer diameter and outlet width, can be accurately determined. The optimal design parameters of the impeller under the design requirements can be obtained accurately and efficiently. The designed constant-pressure impeller can improve the stability and reliability of the aircraft fuel system. At the same time, by optimizing the airfoil design of the main blades and auxiliary blades, the intermediate flow channel between the main blades and auxiliary blades is directly connected to the pump back chamber. The designed impeller can effectively reduce the axial force of the impeller, improve / regulate the pressure distribution, improve the medium flow state, reduce flow loss, improve the oil suction / pumping performance of the high-speed fuel pump, and improve the overall hydraulic efficiency of the pump.

[0099] It should be noted that all directional indicators (such as up, down, left, right, front, back, horizontal, vertical, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly. The "connection" can be a direct connection or an indirect connection. The "set", "set in", and "set at" can be a direct setting or an indirect setting.

[0100] The above embodiments are illustrative of the present invention and not intended to limit the invention. It is understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the invention. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A design method for a constant pressure impeller in a high-speed fuel pump, characterized in that: It includes the following steps: (1) For the original impeller model, use the ratio of flow interval differences to determine whether the constant pressure condition is met; The flow rate range is divided into sections, and the ratio of the difference between the flow rate and the head at each end is as follows: ； Wherein, head Hn is dimensionless head and flow rate Qn is dimensionless flow rate; If the above conditions are not met, proceed to the next step of adjusting the original impeller model; (2) If not satisfied, collect head H, dynamic head Hv and potential head Hp under different flow rates. Based on the correlation analysis between the dynamic head Hv set, the potential head Hp set and the head H set respectively, parametric design is carried out on the geometric parameters that affect the constant pressure effect of the impeller. The data of head H, dynamic head Hv, and potential head Hp under different flow rates are obtained from the following relationship: Hp = H - Hv The formula for collecting the head Hv is: ； v1—impeller inlet velocity, v2—impeller outlet velocity, g—gravitational acceleration; Correlation analysis of dynamic head Hv set, potential head Hp set, and head H set: Person correlation coefficient was used to evaluate the correlation between dynamic head Hv set and head H set, and potential head Hp set and head H set, with correlation coefficients Pv and Pp, respectively. The formula for calculating Person correlation coefficient is as follows: ； cov(X,Y) — covariance of X,Y; σX, σY — standard deviation of X,Y; The standard for assessing correlation is: the larger the correlation coefficient P value, the higher the correlation; if the correlation coefficient Pv is large, it can be based on the formula: ； Parametric design of impeller geometry parameters; if the correlation coefficient Pp is large, then based on the formula relating dynamic head and potential head: ； Parametric design of impeller geometry parameters; (3) Then, the impeller blades are optimized to suppress the vortex generated under low flow conditions and regulate the dynamic head under low flow conditions, so that the final impeller model satisfies the flow range difference ratio relationship and thus has a constant pressure effect. The impeller geometry parameters include: impeller outlet diameter D2, impeller outlet width b2, number of blades z, blade inlet angle β1, blade outlet angle β2, and blade thickness s; The impeller outlet diameter D2 and impeller outlet width b2 are calculated based on the dynamic head calculation formula: ； n—rotation speed, Hd—design head, H—actual head under the original model's design flow rate; ； β2—blade exit angle, k2—blade exit displacement coefficient, ηv—volume efficiency, W—finite blade number correction coefficient; Number of blades: 2 ≤ z ≤ 8; Blade inlet angle: 10° < β1 < 35°; Blade exit angle: 20 < β2 < 90°; Blade thickness: 1≤s≤6mm; Finite blade correction factor: 0.2 <W<0.5; The blade exit angle β2 includes: the main blade exit angle β21 and the secondary blade exit angle β22, and β21≥β22; During the design calculations, the dimensionless numerical values ​​of each parameter are used for the design calculations.

2. A high-speed fuel pump constant-pressure impeller designed using the design method described in claim 1, wherein the fuel pump is a centrifugal pump, comprising a front cover plate (1), a rear cover plate (2), blades (3), main blades (4), auxiliary blades (5), and an intermediate flow channel (6), wherein multiple blades are evenly distributed circumferentially and connected between the front cover plate and the rear cover plate, each blade having a main blade and an auxiliary blade, the blades being "Y"-shaped, the profiles of the main blades and auxiliary blades having airfoil characteristics, the main blades and auxiliary blades forming an intermediate flow channel, and the radially inner ends of the main blades and auxiliary blades being connected to a common blade section; characterized in that: The intermediate flow channel (6) passes through the rear cover plate and is directly connected to the pump rear cavity. A connecting hole (7) is provided on the auxiliary blade. The connecting hole connects the pressure surface and the negative pressure surface of the auxiliary blade respectively. That is, the connecting hole connects the intermediate flow channel and the concave arc surface of the auxiliary blade respectively.

3. The high-speed fuel pump constant pressure impeller as described in claim 2, characterized in that, The concave arc surface of the main blade (4) near the secondary blade is provided with a concave portion (8) and a convex portion (9), the concave portion and the convex portion are arranged adjacent to each other, and the concave portion and the convex portion are located radially outside the connecting hole (7).

4. The high-speed fuel pump constant pressure impeller as described in claim 3, characterized in that, The concave portion (8) and convex portion (9) have a triangular structure and a centrally symmetrical structure.

5. A high-speed fuel pump constant pressure impeller as described in claim 4, characterized in that, The convex surface of the main blade (4) includes a first arc surface (41) and a second arc surface. The radius of the first arc surface is greater than the radius of the second arc surface, and the center line of the connecting hole (7) is set parallel to the first arc surface. The center line of the connecting hole passes through one corner or corner endpoint of the triangle of the protrusion (9).

6. A high-speed fuel pump constant pressure impeller as described in claim 5, characterized in that, The profiles of the main blade (4) and the secondary blade (5) have airfoil characteristics. The thickness of the main blade and the secondary blade is non-equal, and the main blade and / or the secondary blade has more than 5 different thickness values.

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