Design structure and design method of blade frequency control of shrouded blisk

Abstract

The application discloses a design structure and a design method of blade frequency control of a shrouded blisk. The design structure comprises a shrouded blisk, a chamfered joint is arranged on the peripheral surface of the shroud of the shrouded blisk, an air inlet edge groove is arranged on the air inlet edge of the shroud of the shrouded blisk, and an air outlet edge groove is arranged on the air outlet edge of the shroud of the shrouded blisk. The design method comprises the following steps: calculating the required frequency of the blade of the shrouded blisk through strength evaluation; and finally determining the values of k2, k3, k4, k5, k6, k7 and k8 by iteratively calculating the blade frequency through different values of the joint width, the first and second angles of the shroud, the shroud depth, the first angle of the air inlet edge groove and the air outlet edge groove. The application has the advantages of simple operation, reliable control, strong operability, accurate adjustment and control of the blade frequency in the late stage of the blisk processing, and the like.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of aero-engines and gas turbines, and particularly relates to a design structure and a design method for blade frequency control of a shroud integral blade disk. BACKGROUND

[0002] The service life of an aero-engine is mainly determined by the hot end components, and a long-life and high-reliability turbine integral blade disk is a key component of a small engine. The shroud integral blade disk is a conventional design structure of a turbine component of an aero-engine. The blade disk reduces the tip sealing gap through the shroud design, can improve the working efficiency of the blade, and greatly reduces the use proportion of cooling air.

[0003] During high-speed operation of the shroud integral blade disk in a high-temperature environment, the vibration stress control difficulty needs to be solved, and after the design is completed, the high-cycle fatigue strength reserve of the maximum vibration stress of each order needs to be ensured to meet the requirements. If necessary, the blade vibration frequency needs to be controlled within a certain range to avoid cracks in the blade due to excessive stress during use, thereby causing a major failure. Due to the integral casting of the disk body and the blade of the integral blade disk, the blade has no damping structure, and therefore the frequency control has great difficulty. In view of the characteristics of the integral blade disk, such as small damping ratio, multiple vibration peaks near the resonance point, narrow range, and sharp vibration response peak, the natural frequency of the blade needs to be controlled through the blade shape in the early design, and the blade shape directly affects the gas power design of the blade and finally affects the efficiency of the blade. During the casting of the shroud integral blade disk, due to casting deviation and other reasons, the natural frequency of the blade also changes, and the natural frequencies of each blade are inconsistent, showing a discretization characteristic. According to the statistical results, the maximum deviation of the frequency shift can reach 3%, which leads to deviation from the initial design state.

[0004] Based on the above unstable factors, the frequency of the multiple parts of the rotor blade changes after processing, which leads to the problem of being unable to use. SUMMARY

[0005] The application provides a design structure and a design method for blade frequency control of a shroud integral blade disk, which are simple to operate, reliable in control, have strong operability, and can accurately adjust and control the frequency of the blade in the late stage of blade disk processing.

[0006] The application achieves the above-mentioned purpose through the following technical solutions.

[0007] The design structure for blade frequency control of a shroud integral blade disk comprises a shroud integral blade disk, a shroud portion of the shroud integral blade disk is provided with a plurality of inclined cutting seams arranged in the circumferential direction, a gas inlet edge of the shroud portion of the shroud integral blade disk is provided with a plurality of gas inlet edge grooves arranged in the circumferential direction, and a gas outlet edge of the shroud portion of the shroud integral blade disk is provided with a plurality of gas outlet edge grooves arranged in the circumferential direction.

[0008] Further, the chamfering slot has a chamfering slot included angle k1, and the chamfering slot included angle k1 is 35-45 degrees.

[0009] Further, the air inlet side groove is a triangular groove.

[0010] Further, the air inlet side groove has an alpha one side included angle k3, and the alpha one side included angle k3 is 60-70 degrees.

[0011] Further, the air inlet side groove has an alpha groove depth k5, and the alpha groove depth k5 is not more than 1 / 3 of the blade crown width.

[0012] Further, the air outlet side groove is a right-angled trapezoidal groove, and the upper base of the right-angled trapezoid is the groove bottom of the air outlet side groove.

[0013] Further, the air outlet side groove has a beta one side included angle k6, and the beta one side included angle k6 is 65-75 degrees.

[0014] Further, the air outlet side groove has a beta groove depth k7, and the beta groove depth k7 is not more than 1 / 3 of the blade crown width, and the air outlet side groove has a beta groove width k8, and the beta groove width k8 is not more than 1 / 2 of the distance between the blade trailing edges at the blade crown.

[0015] A design method of a blade frequency control of a shrouded blisk, aiming at the design structure of the blade frequency control of the shrouded blisk, comprising:

[0016] Through strength evaluation, the required frequency of the blade of the shrouded blisk is calculated first;

[0017] Different values of the chamfering slot width k2 are selected in combination with the blade vibration reduction demand and the processing mode, and the blade frequency is iteratively calculated through the different values of the chamfering slot width k2, so as to finally determine the value of the chamfering slot width k2.

[0018] Different values of the alpha one side included angle k3, the alpha two side included angle k4 and the alpha groove depth k5 of the air inlet side groove are selected in combination with the blade vibration reduction demand, and the blade frequency is iteratively calculated through the different values of the alpha one side included angle k3, the alpha two side included angle k4 and the alpha groove depth k5, so as to finally determine the values of the alpha one side included angle k3, the alpha two side included angle k4 and the alpha groove depth k5.

[0019] Combining the blade vibration reduction demand, the value k6 of the first side angle of the exhaust side groove, the value k7 of the groove depth and the value k8 of the groove width are selected, the blade frequency is iteratively calculated through the value k6 of the first side angle of the exhaust side groove, the value k7 of the groove depth and the value k8 of the groove width, and finally the value k6 of the first side angle of the exhaust side groove, the value k7 of the groove depth and the value k8 of the groove width are determined.

[0020] The functions realized by the present application are as follows:

[0021] 1. After calculation, a series of grooves with different shapes are machined on both sides of the blade crown of the integral blade disc, and the two sides of the groove are matched to adjust the natural frequency of the blade, improve the vibration mode and improve the high-cycle fatigue life of the blade.

[0022] 2. According to the frequency control requirement, the optimal number of connected blade crowns is determined according to the parameter combination of different materials, use temperature and the like of the integral blade disc with crown, and the blade crown is cut after processing, and the natural frequency of the blade is adjusted by using the connection coupling effect between the blade and the crown.

[0023] 3. According to the frequency control requirement, the optimal groove scheme is designed on both sides of the crown of the integral blade disc with crown according to the parameter combination of different materials, use temperature and the like, and the groove is machined in different shapes and quantities, so that the blade frequency can be accurately controlled within the required range stably in the whole life cycle.

[0024] Advantages of the present application:

[0025] 1. Compared with the traditional method of controlling the natural frequency by designing the blade profile, the frequency error of the present application can be controlled within 0.2%.

[0026] 2. Compared with the traditional integral blade disc with crown, the blade frequency can be corrected after processing to meet the design requirements, and the blade disc rejection rate can be greatly reduced.

[0027] 3. The present application does not affect the early processing technology of the integral blade disc, and can be operated after the integral blade disc is processed.

[0028] 4. The present application does not change the original integral blade disc connection and sealing structure, and the operation is reliable.

[0029] The foregoing main scheme of the present application and each further selected scheme can be freely combined to form multiple schemes, all of which are the schemes that can be adopted and claimed by the present application; and the present application can also be freely combined between (each non-conflicting selection) and other selections. Those skilled in the art can understand that there are many combinations according to the existing technology and common knowledge after understanding the schemes of the present application, and all of them are the technical schemes claimed by the present application, which will not be listed here. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is a schematic diagram of the state of the shrouded blisk before the implementation of the present application.

[0031] Figure 2 is a schematic diagram of the state of the shrouded blisk after the implementation of the present application.

[0032] Figure 3 is a schematic diagram of the structure of the slanted cut seam between the blade crowns of the present application.

[0033] Figure 4 is a schematic diagram of the structure of the (frequency-modulated) inlet edge groove of the present application.

[0034] Figure 5 is a schematic diagram of the structure of the (frequency-modulated) inlet and outlet edge groove of the present application.

[0035] In the figure: 1 - shrouded blisk, 2 - slanted cut seam, 3 - inlet edge groove, 4 - outlet edge groove, 5 - cut seam included angle, 6 - cut seam width, 7 - alpha one included angle, 8 - alpha two included angle, 9 - alpha groove depth, 10 - beta one included angle, 11 - beta groove depth, 12 - beta groove width. DETAILED DESCRIPTION

[0036] The following non-limiting examples are intended to illustrate the present application.

[0037] Example 1

[0038] Reference Figures 1-5 As shown in the figure, a design structure for frequency control of a shrouded blisk blade includes a shrouded blisk 1.

[0039] The crown peripheral surface of the shrouded blisk 1 is provided with a plurality of slanted cut seams 2 arranged at equal intervals (included angles) in the circumferential direction, the inlet edge of the crown of the shrouded blisk 1 is provided with a plurality of inlet edge grooves 3 arranged at equal intervals (included angles) in the circumferential direction, and the outlet edge of the crown of the shrouded blisk 1 is provided with a plurality of outlet edge grooves 4 arranged at equal intervals (included angles) in the circumferential direction.

[0040] The slanted cut seam 2 includes two dimensions, a cut seam included angle 5 and a cut seam width 6. The cut seam included angle 5 is the included angle between the cut seam direction and the center axis of the blisk, and the value of the cut seam included angle 5 is k1, which is designed according to the blade profile, and is preferably 35°-45°. The value of the cut seam width 6 of the slanted cut seam 2 is k2, and is preferably 0.1 mm or 0.2 mm. After cutting, it is ensured that the cut seam passes through the middle part of the two side blades, so as to ensure the blade profile and the rounded part of the blade tip, and to not affect the strength requirement of the blade tip.

[0041] The air inlet side groove 3 is a triangular groove, and the air inlet side groove 3 includes three dimensions, i.e., an alpha one side angle 7, an alpha two side angle 8, and an alpha groove depth 9. The alpha one side angle 7 and the alpha two side angle 8 are both the angles between the triangular inclined side and the center axis of the disc, the value of the alpha one side angle 7 is k3, and preferably k3 is 60°-70°, and the value of the alpha two side angle 8 of the air inlet side groove 3 is k4, and preferably k4 is 60°-70°.

[0042] The value of the alpha groove depth 9 is k5, which is determined according to the specific blade structure characteristics, and preferably k5 is not greater than 1 / 3 of the blade crown width. After the groove is machined, the blade tip and the rounded part are ensured to be complete, so as to ensure the blade shape and the rounded part of the blade tip, and to not affect the strength requirement of the blade tip.

[0043] The air outlet side groove 4 is a right-angled trapezoidal groove, the upper base of the right-angled trapezoid is the groove bottom of the air outlet side groove 4, and the air outlet side groove 4 includes a beta one side angle 10, a beta groove depth 11, and a beta groove width 12. The beta one side angle 10 is the angle between the inclined side of the right-angled trapezoid and the center axis of the disc, and the value of the beta one side angle 10 is k6, and preferably k6 is 65°-75°.

[0044] The value of the beta groove depth 11 is k7, and the value of the beta groove width 12 is k8, k7 and k8 are determined according to the specific blade structure characteristics, and preferably k7 is not greater than 1 / 3 of the blade crown width, and k8 is not greater than 1 / 2 of the distance between the blade trailing edges at the blade crown. After the groove is machined, the blade tip and the rounded part are ensured to be complete, so as to ensure the blade shape and the rounded part of the blade tip, and to not affect the strength requirement of the blade tip.

[0045] Embodiment 2

[0046] Reference Figures 1-5 As shown in the figure, a design method of the blade frequency control of the shrouded integral disc, which can be used for the blade frequency adjustment of all shrouded integral discs, including:

[0047] In the implementation, through strength evaluation, the required frequency of the blade of the shrouded integral disc 1 is calculated first;

[0048] Combined with the blade vibration reduction requirement and the processing mode, the value k2 of the slit width 6 of the chamfered slit 2 is selected, the blade frequency is iteratively calculated through the different values k2 of the slit width 6, and finally the value k2 of the slit width 6 is determined, so as to change the original frequency of the blade to be away from the dangerous frequency range and meet the strength design criterion requirement.

[0049] The value of the chamfering angle 5 is k1, and k1 is designed according to the blade profile, and k1 is preferably 35°-45°. The value of the chamfering width 6 of the chamfering 2 is k2, and k2 is preferably 0.1 mm or 0.2 mm. After cutting, the chamfering is ensured to pass through the middle part of the two side blades, so as to ensure the blade profile and the rounded part of the blade tip, and to not affect the strength requirement of the blade tip.

[0050] According to the blade vibration reduction requirement, the values of the alpha one-side angle 7, the alpha two-side angle 8 and the alpha groove depth 9 of the air inlet side groove 3 are selected to be k3, k4 and k5 respectively, the blade frequency is iteratively calculated according to the values of the alpha one-side angle 7, the alpha two-side angle 8 and the alpha groove depth 9, and finally the values of the alpha one-side angle 7, the alpha two-side angle 8 and the alpha groove depth 9 are determined to change the original frequency of the blade to be away from the harmful frequency range and meet the strength design criterion requirement.

[0051] The value of the alpha one-side angle 7 is k3, and k3 is preferably 60°-70°. The value of the alpha two-side angle 8 of the air inlet side groove 3 is k4, and k4 is preferably 60°-70°. The value of the alpha groove depth 9 is k5, and k5 is determined according to the specific blade structure characteristics, and k5 is preferably not more than 1 / 3 of the blade crown width. After the groove is processed, the blade tip and the rounded part thereof are ensured to be complete, so as to ensure the blade profile and the rounded part of the blade tip, and to not affect the strength requirement of the blade tip.

[0052] According to the blade vibration reduction requirement, the values of the beta one-side angle 10, the beta groove depth 11 and the beta groove width 12 of the air outlet side groove 4 are selected to be k6, k7 and k8 respectively, the blade frequency is iteratively calculated according to the values of the beta one-side angle 10, the beta groove depth 11 and the beta groove width 12, and finally the values of the beta one-side angle 10, the beta groove depth 11 and the beta groove width 12 are determined to change the original frequency of the blade to be away from the harmful frequency range and meet the strength design criterion requirement.

[0053] The value of the beta one-side angle 10 is k6, and k6 is preferably 65°-75°. The value of the beta groove depth 11 is k7, and the value of the beta groove width 12 is k8, and k7 and k8 are determined according to the specific blade structure characteristics, and k7 is preferably not more than 1 / 3 of the blade crown width, and k8 is preferably not more than 1 / 2 of the distance between the blade trailing edges at the blade crown. After the groove is processed, the blade tip and the rounded part thereof are ensured to be complete, so as to ensure the blade profile and the rounded part of the blade tip, and to not affect the strength requirement of the blade tip.

[0054] The foregoing basic examples and each further selected example of the present application can be freely combined to form a plurality of embodiments, all of which are embodiments that can be adopted and claimed by the present application. In the present application scheme, each selected example can be arbitrarily combined with any basic example and selected example.

[0055] The above description is only the preferred embodiment of the present application, and is not intended to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A design structure for controlling the blade frequency of a crowned integral bladed disc, comprising a crowned integral bladed disc (1), characterized in that: The crown of the integral bladed disk (1) is provided with several oblique cuts (2) arranged in the circumferential direction on the circumferential surface of the crown, and several air inlet grooves (3) arranged in the circumferential direction are provided on the air inlet side of the crown of the integral bladed disk (1), and several air outlet grooves (4) arranged in the circumferential direction are provided on the air outlet side of the crown of the integral bladed disk (1). The air intake side groove (3) is a triangular groove; the exhaust side groove (4) is a right-angled trapezoidal groove, and the upper base of the right-angled trapezoid is the bottom of the exhaust side groove (4); The intake side groove includes three dimensions: the included angle of one side of the blade, the included angle of the two sides of the blade, and the depth of the groove. The included angle of one side of the blade and the included angle of the two sides of the blade are both the included angles between the hypotenuse of the triangle and the central axis of the blade disk. The exhaust side groove includes the included angle of side B, the depth of groove B, and the width of groove B. The included angle of side B is the angle between the hypotenuse of the right trapezoid and the central axis of the impeller.

2. The design structure for controlling the blade frequency of a crowned integral bladed disk according to claim 1, characterized in that: The cut angle (5) of the oblique cut (2) is k1, k1 is 35°~45°, and the cut width (6) of the oblique cut (2) is k2, k2 is 0.1mm or 0.2mm.

3. The design structure for controlling the blade frequency of a crowned integral bladed disk according to claim 1, characterized in that: The value of the included angle (7) of the first side of the air intake groove (3) is k3, k3 is 60°~70°, and the value of the included angle (8) of the second side of the air intake groove (3) is k4, k4 is 60°~70°.

4. The design structure for controlling the blade frequency of a crowned integral bladed disk according to claim 1 or 3, characterized in that: The value of the groove depth (9) of the air intake side groove (3) is k5, and k5 is not greater than 1 / 3 of the blade crown width.

5. The design structure for controlling the blade frequency of a crowned integral bladed disk according to claim 1, characterized in that: The value of the included angle (10) of the second side of the exhaust side groove (4) is k6, where k6 is 65°~75°.

6. The design structure for controlling the blade frequency of a crowned integral bladed disk according to claim 1 or 5, characterized in that: The value of the groove depth (11) of the exhaust side groove (4) is k7, which is not greater than 1 / 3 of the width of the leaf crown, and the value of the groove width (12) of the exhaust side groove (4) is k8, which is not greater than 1 / 2 of the distance between the trailing edges of the blades at the leaf crown.

7. A design method for controlling the blade frequency of a crowned integral bladed disk, relating to the design structure for controlling the blade frequency of a crowned integral bladed disk as described in any one of claims 1 to 6, characterized in that, include: Through intensity assessment, the required leaf frequency of the crowned whole leaf disc (1) was first calculated; Based on the blade vibration reduction requirements and processing method, different values ​​of cut width (6) k2 of oblique cut (2) are selected. By using different values ​​of cut width (6) k2, the blade frequency is iteratively calculated, and finally the value of cut width (6) k2 is determined. Based on the blade vibration reduction requirements, different values ​​of the included angle (7) of the first side of the inlet groove (3) k3, the included angle (8) of the second side of the first side k4, and the groove depth (9) of the first side k5 are selected. By using different values ​​of the included angle (7) of the first side of the first side k3, the included angle (8) of the second side of the first side k4, and the groove depth (9) of the first side k5, the blade frequency is iteratively calculated, and finally the values ​​of the included angle (7) of the first side k3, the included angle (8) of the second side k4, and the groove depth (9) of the first side k5 are determined. Based on the blade vibration reduction requirements, different values ​​of the included angle (10) of the exhaust side groove (4), the included depth (11) of the groove, the included depth (11) of the groove, and the included width (12) of the groove are selected. The blade frequency is iteratively calculated by using different values ​​of the included angle (10) of the groove, the included depth (11) of the groove, and the included width (12) of the groove, and finally the values ​​of the included angle (10) of the groove, the included depth (11) of the groove, and the included width (12) of the groove are determined.

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