Reaming design method for cylindrical film hole blockage

Abstract

The invention discloses a broaching design method for cylindrical film hole blockage, and belongs to the technical field of turbines. The method comprises the following steps: constructing an in-hole plugging geometric model of a spraying plugging hole; establishing a mathematical model for calculating the cold air outflow area; setting an aperture amplification factor; selecting a mathematical model of a corresponding cold air outflow area and a blockage range angle, and calculating an aperture amplification factor; establishing a target equation taking the aperture amplification factor as a variable; solving an aperture amplification factor; whether the relative deviation between the cold air outflow area of the cylindrical air film hole obtained after iteration and subjected to spraying blockage and the designed cold air outflow area of the original cylindrical air film hole meets the precision requirement or not is judged, wherein the hole diameter of the cylindrical air film hole obtained after iteration and subjected to spraying blockage; and performing reaming design on the original cylindrical film hole according to the finally obtained aperture amplification factor. The method has universality, computability and engineering applicability, and is particularly suitable for anti-blocking modification design of existing turbine blade film holes.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of turbine machinery fine thermal analysis and high-efficiency cooling technology, and particularly relates to a reaming design method for cylindrical gas film hole blockage. BACKGROUND

[0002] The turbine blade of an aero-engine works in a high-temperature and high-pressure environment, and its cooling performance is directly related to the reliability and service life of the engine. However, in the manufacturing process, due to the requirements of the process and the influence of manufacturing errors, there is a large deviation between the actual cooling structure and the design stage. Taking a typical cooling structure gas film hole as an example, by arranging the gas film hole on the surface of the blade, the cooling gas is injected to form a heat-insulating gas film to isolate the high-temperature gas.

[0003] At present, the electric spark hole making is widely used in manufacturing turbine cooling structures due to its advantages of no contact stress and smooth hole wall. However, due to the requirement of the material conductivity of the process, the process flow of first hole making and then spraying coating is adopted. Under the condition of high temperature and high load, the turbine sprayed thermal barrier coating is relatively thick, and the blockage near the hole outlet is inevitable. The reduction of the cooling gas outlet will cause the jet to lift, reduce the gas film cooling performance, and further threaten the safe operation of the turbine. Therefore, the design of the gas film cooling structure under the premise of hole blockage is the key to avoid overestimating the cooling performance in the design stage and to ensure the efficient cooling of the turbine in the service process.

[0004] This kind of hole blockage is a common damage form for both cylindrical and shaped holes, which has a significant impact on the film cooling effectiveness. In the article "Effect of partial blockage on flow and heat transfer of film cooling with cylindrical and fan-shaped holes" (International Journal of Thermal Sciences, 2021, Vol. 164, Article No. 106866), the authors show the film cooling performance after the blockage of cylindrical and fan-shaped holes. After the blockage of cylindrical holes, the cold air is blown away severely, and after the blockage of fan-shaped holes, the outlet width of the cold air does not decrease significantly, and the cooling performance is improved to a certain extent. However, the processing difficulty is high, the cost is high, and it is not suitable for the widely used cylindrical hole system. In the article "Statistical evaluation on cooling unsteadiness level for a cylindrical film-hole influenced by partial blockage under pulsed mainstream" (International Communications in Heat and Mass Transfer, 2024, Vol. 155, Article No. 107496), the authors study the influence of the pulsed mainstream on the cooling performance of the blocked cylindrical hole. Compared with the steady mainstream, the pulsed mainstream only brings a 12% improvement in film cooling performance under large blockage conditions.

[0005] Currently, there is no special design method for cylindrical holes to maintain cooling performance under spray blockage conditions, which often overestimates the cooling effect in the design stage, and the cooling performance is insufficient in actual service. Therefore, there is an urgent need for a hole expansion design method for cylindrical film holes under blockage, which can maintain the original hole shape and process route, and ensure that the designed cold air outlet area and cooling performance can still be maintained after spray blockage by pre-computation and hole diameter compensation, thereby improving the reliability and service life of turbine blades. SUMMARY

[0006] The technical problem to be solved is: In order to avoid the shortcomings of the prior art, the present application provides a hole expansion design method for cylindrical film holes under blockage, which offsets the area loss caused by spray blockage by pre-expanding the hole, thereby maintaining the film cooling performance without changing the hole type and process. Compared with the existing solutions that optimize the blockage resistance through structure modeling or complex hole shape, the present application is more universal, calculable and engineering applicable, especially suitable for anti-blocking design and modification of existing turbine blade cylindrical film holes.

[0007] The technical solution of the present application is: a reaming design method for cylindrical gas film hole blockage, comprising the following steps: Step 1: Determine the starting position, contour line and connection method of the blockage in the cylindrical gas film hole, and construct a hole blockage geometry model for spraying; Step 2: Identify the influence area of the blockage on the cold gas outflow in the radial circular cross section of the hole blockage geometry model, divide the circular cross section into a cold gas outflow area and a blockage area, and establish a mathematical model for calculating the cold gas outflow area; When the blockage height is less than the radius of the original cylindrical gas film hole, a first mathematical model between the cold gas outflow area and the blockage range angle is established; When the blockage height is greater than or equal to the radius of the original cylindrical gas film hole, a second mathematical model between the cold gas outflow area and the blockage range angle is established; Step 3: Set the hole diameter enlargement factor, so that the cold gas outflow area of the cylindrical gas film hole after the hole diameter is enlarged after experiencing spraying blockage is equal to the design cold gas outflow area of the original cylindrical gas film hole; Step 4: Set the blockage height threshold, and according to the comparison result of the blockage height threshold and the blockage height, select the corresponding mathematical model of the cold gas outflow area and the blockage range angle, and calculate the hole diameter enlargement factor; Step 5: Based on the selected mathematical model, a target equation with the hole diameter enlargement factor as the variable is established; Step 6: Numerical iteration method is used to solve the target equation to obtain the numerical solution of the hole diameter enlargement factor; Step 7: Determine whether the relative deviation of the cold gas outflow area of the cylindrical gas film hole after the hole diameter is enlarged after experiencing spraying blockage and the design cold gas outflow area of the original cylindrical gas film hole is less than 1%, if yes, terminate the calculation and output the hole diameter enlargement factor; if not, continue iteration until the accuracy requirement is met; Step 8: According to the finally obtained hole diameter enlargement factor, the original cylindrical gas film hole is reamed. A further technical solution of the present application is: the construction method of the hole blockage geometry model for spraying: the starting position of the blockage is set at the intersection of the vertical line drawn downward from the up end point on the leeward side of the axial cross section of the cylindrical gas film hole and the windward side, the blockage height is the same as the coating thickness, the blockage contour line parallel to the local windward side inclination angle is drawn, and the starting position and the blockage contour line are connected by a tangent arc to complete the hole blockage modeling.

[0008] A further technical solution of the present application is: the first mathematical model is:

[0009] wherein,A is the cold air outflow area of the original cylindrical gas film hole after experiencing spray blockage, R is the radius of the original cylindrical gas film hole, h is the blockage height, α is the blockage range angle.

[0010] A further technical solution of the present application is that the second mathematical model is:

[0011] wherein, R is the radius of the original cylindrical gas film hole, h is the blockage height, α is the blockage range angle.

[0012] A further technical solution of the present application is that the rule for selecting the first mathematical model or the second mathematical model is: The blockage height threshold is set as ; If , the first mathematical model is selected, and the equation for calculating the hole diameter amplification factor is as follows:

[0013] If , the second mathematical model is selected, and the equation for calculating the hole diameter amplification factor is as follows:

[0014] wherein, A 1 is the designed cold air outflow area of the original cylindrical gas film hole, A 2 is the cold air outflow area of the cylindrical gas film hole after the hole diameter is expanded and after experiencing spray blockage.

[0015] A further technical solution of the present application is that the calculation formula of the hole diameter amplification factor is as follows: If ,

[0016] If , .

[0017] A further technical solution of the present application is that the numerical iteration method is the Newton-Raphson method, and the iteration formula is:

[0018] wherein, is the first iteration value, n is the second iteration value.the aperture amplification factor value of the sub-iteration, is a function the first derivative at . A further technical solution of the present application is that the termination condition of the iteration is:

[0019] wherein, A 1 is the design cold air outflow area of the original cylindrical film hole, A 2 is the cold air outflow area of the cylindrical film hole after aperture expansion after experiencing spray plugging.

[0020] An aperture expansion design system for cylindrical film hole plugging, comprising: A plugging modeling module for establishing an in-hole plugging geometry model of a spray-plugged hole according to the thickness of the thermal barrier coating, which defines the starting point of the plugging material as the intersection of the perpendicular line from the upper end point on the leeward side of the axial cross section of the cylindrical film hole and the windward side, and connects the point with the plugging profile line parallel to the windward side inclination angle with a tangent circular arc; A region identification module connected to the plugging modeling module, for identifying and distinguishing the plugging region formed by the plugging material and the remaining cold air outflow region in the radial circular cross section of the cylindrical film hole; A model construction and selection module connected to the region identification module, for calling a first mathematical model or a second mathematical model according to the size relationship between the plugging material height and the original cylindrical film hole radius; An aperture amplification factor calculation module connected to the model construction and selection module, which is characterized by setting an aperture amplification factor and solving the factor through iterative calculation, so that the cold air outflow area of the expanded cylindrical film hole after plugging is equal to the design cold air outflow area of the original cylindrical film hole; An iteration control and output module connected to the aperture amplification factor calculation module, for controlling the convergence accuracy of the numerical iteration process, and when the relative deviation of the cold air outflow area of the cylindrical film hole after aperture expansion after experiencing spray plugging and the design cold air outflow area of the original cylindrical film hole is less than 1%, the iteration is terminated and the final aperture amplification factor is output, thereby determining the required aperture expansion diameter.

[0021] A turbine blade, the cylindrical film hole on the surface of which is designed using the aperture expansion design method for cylindrical film hole plugging, so that the cylindrical film hole can still maintain a cold air outflow area and cooling performance comparable to the design stage after plugging of the sprayed thermal barrier coating.

[0022] Advantages The beneficial effects of the present application are that the hole expansion design method for the plugging of the cylindrical gas film hole provided by the present application can ensure that the original cold gas outflow area is maintained after spraying plugging through pre-hole expansion calculation of the cylindrical gas film hole, thereby effectively avoiding the decrease of cooling performance. The specific advantage analysis is as follows: 1. The present application compensates for the outlet area loss caused by thermal barrier coating spraying through accurate pre-hole expansion design of the cylindrical gas film hole, ensures that the actual cold gas outflow area after plugging is highly consistent with the design value (deviation <1%), thereby effectively avoiding the decrease of cooling efficiency, ensuring the safe operation of the turbine blade in a high temperature environment, and prolonging the service life thereof.

[0023] 2. The present application establishes a rigorous mathematical model between the height of the plugging and the required hole diameter amplification factor, and provides a complete iterative solution algorithm, which changes the design process from the traditional trial-and-error mode relying on experience to a predictable and calculable precise design mode, significantly improving the scientificity and reliability of the design.

[0024] 3. The present application method innovatively selects two different calculation models according to the relative size relationship between the height of the plugging and the hole radius, and can comprehensively cover various actual working conditions from slight plugging to severe plugging.

[0025] 4. The present application uses Newton-Raphson numerical iteration method to solve nonlinear equations, which has fast convergence speed and high calculation precision, can quickly obtain the hole diameter amplification factor meeting the engineering precision requirement, and is very suitable for batch calculation and optimization integrated in the modern turbine design process.

[0026] 5. Unlike the scheme of using complex shaped holes (such as fan-shaped holes, Coanda bulges, etc.) or special gradual expansion structures to improve the anti-plugging performance in the prior art, the present application finally retains the traditional cylindrical hole structure, does not need to change the existing electric spark hole making and spraying process route, greatly reduces the process difficulty and manufacturing cost of existing product improvement and new product design. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 It is a schematic diagram of the in-hole plugging geometric model of the sprayed hole in the embodiment of the present application; Figure 2 It is a schematic diagram of the radial circular cross section in the plugged cylindrical gas film hole in the embodiment of the present application; Figure 3 It is a schematic diagram of the original cylindrical gas film hole structure and the enlarged hole diameter and plugged cylindrical gas film hole structure in the embodiment of the present application; Figure 4 It is a schematic diagram of the flat plate gas film cooling calculation domain of the plugged cylindrical gas film hole in the embodiment of the present application; Figure 5A comparison chart of original, clogging and aperture amplification and clogging gas film cooling effect distribution in the embodiment of the present application; Figure 6 A comparison chart of original, clogging and aperture amplification and clogging average gas film cooling effect distribution in the embodiment of the present application. DETAILED DESCRIPTION

[0028] The embodiments described below with reference to the drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0029] Based on the problems in the prior art that complex shaped holes (such as fan-shaped holes, Coanda bulges, etc.) or special expanding structures are used to improve the anti-clogging performance, the present application proposes a hole expansion design method for clogging of a cylindrical gas film hole. By establishing a mathematical model and an accurate equation set, the calculation method of the hole diameter amplification factor can be adaptively adjusted according to the size relationship between the clogging height and the radius of the gas film hole, so as to ensure the constant cold gas outflow area. The specific technical solutions are as follows: The present application proposes a hole expansion design method for clogging of a cylindrical gas film hole, comprising the following steps: Step 1: Determine the starting position, contour line and connection mode of the clogging object in the cylindrical gas film hole, and construct a hole clogging geometry model for spraying; Step 2: Identify the influence area of the clogging object on the cold gas outflow in the radial circular cross section of the hole clogging geometry model, divide the circular cross section into a cold gas outflow area and a clogging area, and establish a mathematical model for calculating the cold gas outflow area; When the clogging height is less than the radius of the original cylindrical gas film hole, a first mathematical model between the cold gas outflow area and the clogging range angle is established; When the clogging height is greater than or equal to the radius R of the original cylindrical gas film hole, a second mathematical model between the cold gas outflow area and the clogging range angle is established; Step 3: Set the hole diameter amplification factor, so that the cold gas outflow area of the cylindrical gas film hole after the hole diameter expansion after spraying is equal to the design cold gas outflow area of the original cylindrical gas film hole; Step 4: According to the size relationship between the clogging height and the clogging height threshold , select the corresponding mathematical model of the cold gas outflow area and the clogging range angle, and calculate the hole diameter amplification factor; Step 5: Based on the selected mathematical model, a target equation with the hole diameter amplification factor as the variable is established; Step 6: The numerical iteration method is used to solve the target equation to obtain the numerical solution of the hole diameter amplification factor; Step 7: Determine whether the relative deviation of the cold gas outflow area of the cylindrical gas film hole with enlarged aperture after experiencing spray blockage from the designed cold gas outflow area of the original cylindrical gas film hole is less than 1% after iteration, if yes, terminate the calculation and output the aperture enlargement factor; if no, continue iteration until the accuracy requirement is met; Step 8: According to the finally obtained aperture enlargement factor, the original cylindrical gas film hole is designed to be enlarged.

[0030] In one embodiment: the construction method of the in-hole blockage geometry model of the spray blockage hole: the starting position of the blockage is set at the intersection of the vertical line drawn downward from the up end point on the leeward side of the axial section of the cylindrical gas film hole and the windward side, the blockage height is the same as the coating thickness, the blockage contour line parallel to the local windward side inclination angle is drawn, and the starting position and the blockage contour line are connected by a tangent circular arc to complete the in-hole blockage modeling.

[0031] In one embodiment: the first mathematical model is:

[0032] wherein, A is the cold gas outflow area of the original cylindrical gas film hole after experiencing spray blockage, R is the radius of the original cylindrical gas film hole, h is the blockage height, α is the blockage range angle.

[0033] In one embodiment: the second mathematical model is:

[0034] wherein, A is the cold gas outflow area of the original cylindrical gas film hole after experiencing spray blockage, R is the radius of the original cylindrical gas film hole, h is the blockage height, α is the blockage range angle.

[0035] In one embodiment: the selection rule of the mathematical model is as follows: If , the first mathematical model is selected to obtain the equation for calculating the aperture enlargement factor as follows:

[0036] If , the second mathematical model is selected to obtain the equation for calculating the aperture enlargement factor as follows: .

[0037] In one embodiment: the aperture magnification factor The calculation formula is as follows: like ,

[0038] like , .

[0039] In one embodiment, the numerical iteration method is the Newton-Raphson method, and its iteration formula is:

[0040] in, For the n The aperture magnification factor value of the iteration, For function exist The first derivative at . In one embodiment, the termination condition of the iteration is:

[0041] in, A 1 is the designed cold air outflow area of ​​the original cylindrical air film hole, A 2 is the cold air outflow area of ​​the cylindrical air film hole after the aperture is enlarged and blocked by spraying.

[0042] The present invention also proposes a hole expansion design system for cylindrical air film hole blockage, comprising: The blockage modeling module is used to establish a geometric model of the blockage in the spray-coated hole according to the thickness of the thermal barrier coating. The starting point of the blockage is defined as the intersection of the vertical line from the upper end point on the leeward side of the cylindrical air film hole axial section and the windward side, and a tangent arc is used to connect this point with the blockage contour line parallel to the windward side inclination angle; a region identification module, connected to the blockage modeling module, for identifying and distinguishing a blockage region formed by a blockage and a remaining cold air outflow region in a radial circular cross section of the cylindrical air film hole; A model building and selection module, connected to the region identification module, is used to call the first mathematical model or the second mathematical model according to the relationship between the height of the blockage and the radius of the original cylindrical air film hole; The aperture magnification factor calculation module is connected to the model construction and selection module. Its core is to set an aperture magnification factor and solve the factor through iterative calculation so that the cooling air outflow area of ​​the expanded cylindrical air film hole after blocking is equal to the designed cooling air outflow area of ​​the original cylindrical air film hole; The iterative control and output module is connected with the aperture amplification factor calculation module, and is used for controlling the convergence precision of the numerical iteration process, and when the relative deviation of the cold gas outflow area of the calculated aperture-expanded cylindrical film hole after experiencing the spraying blockage and the design cold gas outflow area of the original cylindrical film hole is less than 1%, the iteration is terminated and the final aperture amplification factor is output, so that the required hole expansion diameter is determined.

[0043] The application further provides a turbine blade, wherein the cylindrical film hole on the surface of the turbine blade is designed by using the hole expansion design method for the cylindrical film hole blockage, so that the cylindrical film hole can maintain the cold gas outflow area and the cooling performance equivalent to those in the design stage after the spraying of the thermal barrier coating is blocked.

[0044] The application provides a hole expansion design method for the cylindrical film hole blockage, which uses the Newton-Raphson iteration method to solve the nonlinear equation, quickly and accurately obtains the aperture amplification factor, and ensures that the deviation of the cold gas outflow area after the blockage and the original cylindrical film hole is not more than 1%.

[0045] The above technical solutions are further described in detail below with reference to the drawings: In one embodiment, a hole expansion design method for the cylindrical film hole blockage comprises the following steps: Step 1: refer to Figure 1 As shown in the figure, the hole blockage modeling method for the spraying blockage is established, the starting position of the blockage is located at the intersection of the downward vertical line of the upwind side end point of the cylindrical film hole axial section and the windward side, the original cylindrical film hole diameter is 1.0 mm, the blockage height is 0.28 mm, the blockage contour line parallel to the local upwind side inclination angle is drawn, and the starting position and the blockage contour line are connected by using a tangent circular arc to complete the hole blockage modeling. Step 2: refer to Figure 2 As shown in the figure, the observable blockage height in the radial circular section of the cylindrical film hole is 0.28 mm, and the circular section presents two sector areas, which are divided into a cold gas outflow area and a blockage area. Step 3: the blockage height is less than the radius of the cylindrical film hole (h=0.28 mm < R=0.5 mm), and the mathematical model of the cold gas outflow area and the blockage range angle (the included angle of the two straight lines connecting the two ends of the blockage and the center) is established.

[0046] The mathematical model of the cold gas outflow area and the blockage range angle is as follows:

[0047] Wherein, A is the cold gas outflow area of the original cylindrical film hole after experiencing the spraying blockage, R is the radius of the original cylindrical film hole, hThe plug height, α The plug range angle; Step 4: The cylindrical film hole after the aperture is enlarged has the same cold gas outflow area 0.785mm 2 as the original cylindrical film hole after plugging, ensuring that the cooling performance of the cylindrical film hole after plugging is equivalent to that in the design stage; The same cold gas outflow area is expressed as follows: A 2= A 1=0.785mm 2

[0048] Wherein, A 1 is the design cold gas outflow area of the original cylindrical film hole, A 2 is the cold gas outflow area of the cylindrical film hole after aperture expansion after experiencing spray plugging; Step 5: Under the premise of using the aperture expansion factor in the cylindrical film hole structure, the size relationship between the plug height and the radius of the enlarged cylindrical film hole is determined, so as to select the mathematical model for calculating the aperture expansion factor; The size relationship between the plug height and the plug height threshold is as follows: The cylindrical film hole plug height is h =0.28mm, which is less than The mathematical model for calculating the aperture expansion factor is selected under the condition that the plug height is less than the plug height threshold; Step 6: According to the mathematical model of the cold gas outflow area and the plug range angle in step 3, the equation group for calculating the aperture expansion factor under the condition that The equation group for calculating the aperture expansion factor under the condition that ; Wherein, is the aperture expansion factor; Step 7: and are substituted into the equation , that is, the equation is obtained, and the aperture expansion factor can be obtained by solving the equation; The equation is as follows: ; Step 8: The equation contains an inverse trigonometric function and a quadratic term, and cannot obtain a theoretical solution. Newton-Raphson method is used to obtain the numerical solution of the equation; The calculation process of the Newton-Raphson method is as follows: Function At the initial point , use Taylor expansion: ; Let , that is: ; Solve the next iteration point: ; This process is iterated until the accuracy requirement is met: ; Step 9: As shown in Figure 3 , the iteration termination condition of the aperture amplification factor is that when the aperture is enlarged and blocked, the relative deviation of the cold gas outflow area after blocking and the original cylindrical gas film hole cold gas outflow area is less than 1%, the calculation can be terminated; The iteration termination condition of the aperture amplification factor is as follows: The aperture amplification factor obtained by iteration calculation is = 1.15, and the corresponding cold gas outflow area is A2 = 0.791 mm2, which meets the accuracy requirement of iteration ; Step 10: As shown in Figure 4 , using the blocking modeling method in steps 1 and 9 and the aperture amplification factor, a flat plate gas film cooling calculation domain with a blocking height of 0.28 mm and the same cold gas outflow area as the original cylindrical gas film hole is obtained; Step 11: Grid division and three-dimensional simulation calculation are performed for the flat plate gas film cooling calculation domain, and the flat plate gas film cooling distribution of the original, blocking and aperture amplification and blocking is obtained, specifically: the calculation domain is divided by tetrahedral elements, and the irrelevance verification of grid division and related calculation condition setting are completed, wherein: the turbulence model selects the SST Gamma-Theta model, the main flow adopts velocity inlet and pressure outlet, the cold gas adopts mass flow inlet, and the blowing ratio of the cold gas is 0.5 and 1.0; Step 12: As shown in Figure 5 and Figure 6 , the cylindrical gas film hole with blocking and enlarged aperture obtained by the embodiment is compared with the gas film cooling effect and spanwise average gas film cooling effect of the original and blocked cylindrical gas film hole. After enlarging the aperture, the negative effect of blocking on gas film cooling under the blowing ratio of 0.5 is almost completely eliminated, and the blocked cylindrical gas film hole under the blowing ratio of 1.0 only has a weak decrease in gas film cooling effect.

[0049] Although the embodiments of the present application have been shown and described above, it is understood that the above-described embodiments are exemplary and are not to be construed as limiting the present application, and that changes, modifications, substitutions and variations can be made by those skilled in the art without departing from the spirit and scope of the present application.

Claims

1. A hole expansion design method for cylindrical air film hole blockage, characterized in that: The following steps are involved: Step 1: Determine the starting position, contour line, and connection method of the blockage in the cylindrical air film hole, and construct a geometric model of the blockage in the hole for spray plugging; Step 2: Identify the area of ​​influence of the blockage on the outflow of cold air in the radial circular cross-section of the hole blockage geometric model, divide the circular cross-section into the outflow area of ​​cold air and the blockage area, and establish a mathematical model for calculating the outflow area of ​​cold air. When the height of the obstruction is smaller than the radius of the original cylindrical air film hole, a first mathematical model between the cold air outflow area and the obstruction range angle is established; When the height of the obstruction is greater than or equal to the radius of the original cylindrical air film hole, a second mathematical model is established between the cold air outflow area and the obstruction range angle; Step 3: Set the aperture magnification factor so that the cooling air outflow area of ​​the cylindrical air film hole after the aperture is enlarged and blocked by spraying is equal to the designed cooling air outflow area of ​​the original cylindrical air film hole; Step 4: Set a blockage height threshold. Based on the comparison between the blockage height threshold and the blockage height, select a mathematical model that corresponds to the cold air outflow area and the blockage range angle, and calculate the aperture magnification factor. Step 5: Based on the selected mathematical model, establish the target equation with the aperture magnification factor as the variable; Step 6: Solve the target equation using a numerical iteration method to obtain the numerical solution of the aperture magnification factor; Step 7: Determine whether the relative deviation between the cooling air outflow area of ​​the iteratively enlarged cylindrical film hole after spray blockage and the designed cooling air outflow area of ​​the original cylindrical film hole is less than 1%. If so, terminate the calculation and output the aperture enlargement factor; if not, continue the iteration until the accuracy requirement is met. Step 8: Design the hole expansion of the original cylindrical air film hole according to the final aperture magnification factor.

2. The hole expansion design method for cylindrical air film hole blockage according to claim 1, characterized in that: The method for constructing the geometric model of the in-hole blockage of the spray plugging is as follows: the starting position of the blockage is set at the intersection of the vertical line drawn downward from the upper end point of the leeward side of the axial section of the cylindrical air film hole and the windward side. The height of the blockage is the same as the coating thickness. The blockage contour line parallel to the local windward side inclination angle is drawn. The starting position and the blockage contour line are connected by a tangent arc to complete the in-hole blockage modeling.

3. The hole expansion design method for cylindrical air film hole blockage according to claim 2, characterized in that: The first mathematical model is: in, A is the cold air outflow area of ​​the original cylindrical air film hole after being blocked by spraying, R is the radius of the original cylindrical air film hole, h is the blockage height, α is the blockage range angle.

4. The hole expansion design method for cylindrical air film hole blockage according to claim 3, characterized in that: The second mathematical model is: in, R is the radius of the original cylindrical air film hole, h is the blockage height, α is the blockage range angle.

5. The hole expansion design method for cylindrical air film hole blockage according to claim 4, characterized in that: The rules for selecting the first mathematical model or the second mathematical model are: Set the blockage height threshold to ; like , then the first mathematical model is selected to obtain the calculated aperture magnification factor The equation is as follows: like , then the second mathematical model is selected to obtain the calculated aperture magnification factor The equation is as follows: in, A 1 is the designed cold air outflow area of ​​the original cylindrical air film hole, A 2 is the cold air outflow area of ​​the cylindrical air film hole after the aperture is enlarged and blocked by spraying.

6. The hole expansion design method for cylindrical air film hole blockage according to claim 5, characterized in that: The aperture magnification factor The calculation formula is as follows: like , like , .

7. The hole expansion design method for cylindrical air film hole blockage according to claim 6, characterized in that: The numerical iteration method is the Newton-Raphson method, and its iteration formula is: in, For the n The aperture magnification factor value of the iteration, For function exist The first derivative at .

8. The hole expansion design method for cylindrical air film hole blockage according to claim 7, characterized in that: The termination condition of the iteration is: in, A 1 is the designed cold air outflow area of ​​the original cylindrical air film hole, A 2 is the cold air outflow area of ​​the cylindrical air film hole after the aperture is enlarged and blocked by spraying.

9. A hole expansion design system for cylindrical air film hole blockage, which implements the hole expansion design method for cylindrical air film hole blockage according to any one of claims 1 to 8; characterized in that: include: The blockage modeling module is used to establish a geometric model of the blockage in the spray-coated hole according to the thickness of the thermal barrier coating. The starting point of the blockage is defined as the intersection of the vertical line from the upper end point on the leeward side of the cylindrical air film hole axial section and the windward side, and a tangent arc is used to connect this point with the blockage contour line parallel to the windward side inclination angle; a region identification module, connected to the blockage modeling module, for identifying and distinguishing a blockage region formed by a blockage and a remaining cold air outflow region in a radial circular cross section of the cylindrical air film hole; A model building and selection module, connected to the region identification module, is used to call the first mathematical model or the second mathematical model according to the relationship between the height of the blockage and the radius of the original cylindrical air film hole; The aperture magnification factor calculation module is connected to the model construction and selection module. Its core is to set an aperture magnification factor and solve the factor through iterative calculation so that the cooling air outflow area of ​​the expanded cylindrical air film hole after blocking is equal to the designed cooling air outflow area of ​​the original cylindrical air film hole; The iterative control and output module is connected to the aperture magnification factor calculation module and is used to control the convergence accuracy of the numerical iteration process. When the relative deviation between the cold air outflow area of ​​the cylindrical air film hole after the aperture is enlarged and the designed cold air outflow area of ​​the original cylindrical air film hole after spraying blockage is less than 1%, the iteration is terminated and the final aperture magnification factor is output to determine the required hole expansion diameter.

10. A turbine blade, characterized in that: The cylindrical air film holes on its surface are designed using the hole expansion design method for cylindrical air film hole blockage described in any one of claims 1 to 8, so that after the cylindrical air film holes are blocked by spraying the thermal barrier coating, they can still maintain the cold air outflow area and cooling performance equivalent to those in the design stage.

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