A reaming design method for cylindrical gas film hole blockage

Abstract

The application is a reaming design method for cylindrical gas film hole blockage, belonging to the field of turbine technology; the method steps include: constructing a hole-in-blockage geometric model for spraying hole blocking; establishing a mathematical model for calculating cold gas outflow area; setting a hole diameter amplification factor; selecting a corresponding mathematical model of cold gas outflow area and blockage range angle, calculating the hole diameter amplification factor; establishing a target equation with the hole diameter amplification factor as a variable; solving the hole diameter amplification factor; judging whether the relative deviation of the cold gas outflow area of the cylindrical gas film hole after experiencing spraying blockage after the hole diameter amplification by iteration meets the accuracy requirement or not; and reaming the original cylindrical gas film hole according to the finally obtained hole diameter amplification factor. The application is more universal, calculable and engineering applicable, especially suitable for anti-blocking modification design of existing turbine blade gas 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 film cooling effectiveness. In "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 presented the film cooling performance of cylindrical and fan-shaped holes after partial blockage. After the blockage of cylindrical holes, the cold air is blown away severely. 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 "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 studied the influence of pulsed mainstream on the cooling performance of cylindrical holes after blockage. Compared with steady mainstream, 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 leads to overestimation of cooling effect in the design stage and insufficient cooling performance 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 through pre-calculation and hole diameter compensation, thereby improving the reliability and service life of turbine blades. SUMMARY

[0006] Technical problems to be solved:

[0007] In order to avoid the shortcomings of the prior art, the present application provides a reaming design method for cylindrical gas film hole blockage, which offsets the area loss caused by spraying blockage through pre-reaming, thereby maintaining the gas film cooling performance without changing the hole type and process. Compared with the existing solutions of optimizing blockage resistance through structural modeling or complex hole shape, the present application is more universal, calculable and engineering applicable, and is especially suitable for anti-blocking design and modification of existing turbine blade cylindrical gas film holes.

[0008] The technical solution of the present application is: a reaming design method for cylindrical gas film hole blockage, comprising the following steps:

[0009] Step 1: determining the starting position, contour line and connection mode of the blockage in the cylindrical gas film hole, and constructing a hole blockage geometry model of the spraying blockage;

[0010] Step 2: identifying the influence area of the blockage on the cold gas outflow in the radial circular cross section of the hole blockage geometry model, dividing the circular cross section into a cold gas outflow area and a blockage area, and establishing a mathematical model for calculating the cold gas outflow area;

[0011] When the blockage height is less than the original cylindrical gas film hole radius, a first mathematical model between the cold gas outflow area and the blockage range angle is established;

[0012] When the blockage height is greater than or equal to the original cylindrical gas film hole radius, a second mathematical model between the cold gas outflow area and the blockage range angle is established;

[0013] Step 3: setting a hole diameter amplification 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 designed cold gas outflow area of the original cylindrical gas film hole;

[0014] Step 4: setting a blockage height threshold, and according to the comparison result of the blockage height threshold and the blockage height, selecting the corresponding mathematical model of the cold gas outflow area and the blockage range angle, and calculating the hole diameter amplification factor;

[0015] Step 5: based on the selected mathematical model, establishing a target equation with the hole diameter amplification factor as the variable;

[0016] Step 6: solving the target equation by using a numerical iteration method to obtain a numerical solution of the hole diameter amplification factor;

[0017] Step 7: judging 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 designed cold gas outflow area of the original cylindrical gas film hole is less than 1%, if yes, terminating the calculation and outputting the hole diameter amplification factor; if no, continuing the iteration until the accuracy requirement is met;

[0018] Step 8: according to the final obtained hole diameter amplification factor, the original cylindrical gas film hole is designed to be reamed.

[0019] A further technical solution of the present application is that the method for constructing the geometric model of the hole plug in the spray hole blocking comprises the following steps: setting the starting position of the plug 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 gas film hole and the windward side, setting the height of the plug to be the same as the coating thickness, drawing the contour line of the plug parallel to the local windward side inclination angle, and connecting the starting position and the contour line of the plug by using a tangent circular arc to complete the modeling of the hole plug.

[0020] A further technical solution of the present application is that the first mathematical model is as follows:

[0021]

[0022] wherein, A is the cold gas outflow area of the original cylindrical gas film hole after the spray blocking, R is the radius of the original cylindrical gas film hole, h is the height of the plug, α is the range angle of the plug.

[0023] A further technical solution of the present application is that the second mathematical model is as follows:

[0024]

[0025] wherein, R is the radius of the original cylindrical gas film hole, h is the height of the plug, α is the range angle of the plug.

[0026] A further technical solution of the present application is that the rule for selecting the first mathematical model or the second mathematical model is as follows:

[0027] The height threshold of the plug is set to ;

[0028] If , the first mathematical model is selected, and the equation for calculating the hole diameter amplification factor is as follows:

[0029]

[0030] If , the second mathematical model is selected, and the equation for calculating the hole diameter amplification factor is as follows:

[0031]

[0032] wherein, A1 represents the original cylindrical film cooling hole design cold air outflow area. A 2 represents the cold air outflow area of ​​the cylindrical air film orifice after it has been blocked by spraying.

[0033] A further technical solution of the present invention is: the aperture magnification factor The calculation formula is as follows:

[0034] like ,

[0035] like , .

[0036] A further technical solution of the present invention is: the numerical iteration method is the Newton-Raphson method, and its iteration formula is:

[0037]

[0038] in, For the first n The aperture magnification factor value of the next iteration. For function exist The first derivative at that point.

[0039] A further technical solution of the present invention is: the termination condition of the iteration is:

[0040]

[0041] in, A 1 represents the original cylindrical film cooling hole design cold air outflow area. A 2 represents the cold air outflow area of ​​the cylindrical air film orifice after it has been blocked by spraying.

[0042] A system for enlarging cylindrical film pores to address blockage includes:

[0043] The blockage modeling module is used to establish the geometric model of the blockage inside the sprayed hole based on the thickness of the thermal barrier coating. It defines the starting point of the blockage as the intersection of the vertical line from the upper end of the leeward side of the axial section of the cylindrical air film hole to the windward side, and connects this point with the blockage outline parallel to the windward side angle with a tangent circular arc.

[0044] The region identification module, connected to the blockage modeling module, is used to identify and distinguish the blockage region formed by the blockage and the remaining cold air outflow region in the radial circular cross section of the cylindrical air film orifice.

[0045] The model construction and selection module is connected with the area identification module, and is used for calling a first mathematical model or a second mathematical model according to the size relationship between the blockage height and the original cylindrical film hole radius;

[0046] The aperture amplification factor calculation module is connected with the model construction and selection module, and the core is to set an aperture amplification factor, and the factor is solved through iterative calculation, so that the cold gas outflow area of the cylindrical film hole after the hole expansion is equal to the designed cold gas outflow area of the original cylindrical film hole after the hole expansion.

[0047] 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 cylindrical film hole after the hole expansion after the spraying blockage and the designed 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 outputted, so that the required hole expansion diameter is determined.

[0048] A turbine blade, 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 the design stage after the spraying of the thermal barrier coating is blocked.

[0049] Advantages

[0050] The hole expansion design method for the cylindrical film hole blockage can ensure that the original cold gas outflow area is maintained after the spraying blockage through the pre-hole expansion calculation of the cylindrical film hole, so that the cooling performance is effectively avoided. The specific advantages are as follows:

[0051] 1. The hole expansion design method for the cylindrical film hole blockage can ensure that the original cold gas outflow area is maintained after the spraying blockage through the pre-hole expansion calculation of the cylindrical film hole, so that the cooling performance is effectively avoided. The specific advantages are as follows:

[0052] 2. The hole expansion design method for the cylindrical film hole blockage can ensure that the original cold gas outflow area is maintained after the spraying blockage through the pre-hole expansion calculation of the cylindrical film hole, so that the cooling performance is effectively avoided. The specific advantages are as follows:

[0053] 3. The hole expansion design method for the cylindrical film hole blockage can ensure that the original cold gas outflow area is maintained after the spraying blockage through the pre-hole expansion calculation of the cylindrical film hole, so that the cooling performance is effectively avoided. The specific advantages are as follows:

[0054] 4. The present application adopts Newton-Raphson numerical iterative method to solve nonlinear equations, the algorithm has fast convergence speed and high calculation precision, can quickly obtain aperture amplification factor meeting engineering precision requirement, and is very suitable for integrated batch calculation and optimization in modern turbine design process.

[0055] 5. Unlike the scheme of adopting complex shaped holes (such as fan-shaped holes, Coanda bulges, etc.) or special gradual expansion structures to improve the anti-blocking 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, and greatly reduces the process difficulty and manufacturing cost of existing product improvement and new product design. BRIEF DESCRIPTION OF DRAWINGS

[0056] Figure 1 It is a schematic diagram of the hole plugging geometry model of the sprayed hole plugging in the embodiment of the present application;

[0057] Figure 2 It is a schematic diagram of the radial circular cross section in the blocked cylindrical gas film hole in the embodiment of the present application;

[0058] Figure 3 It is a schematic diagram of the original cylindrical gas film hole structure and the hole diameter enlarged and blocked cylindrical gas film hole structure in the embodiment of the present application;

[0059] Figure 4 It is a schematic diagram of the blocked cylindrical gas film hole flat plate gas film cooling calculation domain in the embodiment of the present application;

[0060] Figure 5 It is a comparison diagram of the original, blocked and hole diameter enlarged and blocked gas film cooling efficiency distribution in the embodiment of the present application;

[0061] Figure 6 It is a comparison diagram of the original, blocked and hole diameter enlarged and blocked average gas film cooling efficiency distribution in the embodiment of the present application. DETAILED DESCRIPTION

[0062] 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.

[0063] Based on the problems existing in the prior art of adopting complex shaped holes (such as fan-shaped holes, Coanda bulges, etc.) or special gradual expansion structures to improve the anti-blocking performance, the present application proposes a hole expansion design method for the blocked cylindrical gas film hole, can adaptively adjust the calculation method of the hole diameter amplification factor according to the size relationship between the different plugging height and the gas film hole radius, and ensure the constant cold gas outflow area through the establishment of mathematical model and accurate calculation equation group. The specific technical scheme is as follows:

[0064] The application provides a reaming design method for cylinder-shaped gas film hole blockage, and comprises the following steps.

[0065] Step 1: determining the starting position, contour line and connection mode of the blockage in the cylinder-shaped gas film hole, and constructing a hole blockage geometry model for spraying hole blockage;

[0066] Step 2: identifying the influence area of the blockage on the cold gas outflow in the radial circular cross section of the hole blockage geometry model, dividing the circular cross section into a cold gas outflow area and a blockage area, and establishing a mathematical model for calculating the cold gas outflow area;

[0067] When the blockage height is less than the radius of the original cylinder-shaped gas film hole, a first mathematical model between the cold gas outflow area and the range angle of the blockage is established;

[0068] When the blockage height is greater than or equal to the radius R of the original cylinder-shaped gas film hole, a second mathematical model between the cold gas outflow area and the range angle of the blockage is established;

[0069] Step 3: setting a hole diameter amplification factor, so that the cold gas outflow area of the cylinder-shaped gas film hole after the hole diameter is enlarged is equal to the designed cold gas outflow area of the original cylinder-shaped gas film hole after the hole is blocked by spraying;

[0070] Step 4: according to the size relationship between the blockage height and the blockage height threshold , selecting the corresponding mathematical model of the cold gas outflow area and the range angle of the blockage, and calculating the hole diameter amplification factor;

[0071] Step 5: based on the selected mathematical model, a target equation with the hole diameter amplification factor as the variable is established;

[0072] Step 6: the numerical iteration method is used to solve the target equation, and the numerical solution of the hole diameter amplification factor is obtained;

[0073] Step 7: judging whether the relative deviation of the cold gas outflow area of the cylinder-shaped gas film hole after the hole diameter is enlarged by the iteration from the designed cold gas outflow area of the original cylinder-shaped gas film hole is less than 1%, if yes, the calculation is terminated and the hole diameter amplification factor is output; if not, the iteration is continued until the accuracy requirement is met;

[0074] Step 8: according to the finally obtained hole diameter amplification factor, the original cylinder-shaped gas film hole is reamed.

[0075] In an embodiment: the construction method of the hole blockage geometry model for spraying hole blockage: 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 cylinder-shaped 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 hole blockage modeling.

[0076] In one embodiment: the first mathematical model is:

[0077]

[0078] wherein, A A0is the cold air outflow area of the original cylindrical gas film hole after experiencing spray clogging, R R0is the radius of the original cylindrical gas film hole, h H is the height of the clogging, α is the range angle of the clogging.

[0079] In one embodiment: the second mathematical model is:

[0080]

[0081] wherein, A A0is the cold air outflow area of the original cylindrical gas film hole after experiencing spray clogging, R R0is the radius of the original cylindrical gas film hole, h H is the height of the clogging, α is the range angle of the clogging.

[0082] In one embodiment: the selection rule of the mathematical model is as follows:

[0083] If , the first mathematical model is selected, and the equation for calculating the aperture amplification factor is as follows:

[0084]

[0085] If , the second mathematical model is selected, and the equation for calculating the aperture amplification factor is as follows:

[0086]

[0087] In one embodiment: the calculation formula of the aperture amplification factor is as follows:

[0088] If ,

[0089] If , .

[0090] In one embodiment: the numerical iteration method is the Newton-Raphson method, and the iteration formula is:

[0091]

[0092] wherein, is the aperture magnification factor value for the n th iteration, is the function is the first derivative of the function at the point

[0093] In one embodiment: the termination condition for the iteration is:

[0094]

[0095] wherein, A 1 is the design cold gas efflux area of the original cylindrical film hole, A 2 is the cold gas efflux area of the cylindrical film hole after aperture expansion, after experiencing spray clogging.

[0096] The present application also proposes an aperture expansion design system for cylindrical film hole clogging, comprising:

[0097] a clogging modeling module, configured to establish an in-hole clogging geometric model of the spray clogged hole according to the thermal barrier coating thickness, define the clogging starting point as the intersection of the lower perpendicular line of the upper end point on the leeward side of the axial cross section of the cylindrical film hole and the windward side, and connect the point and the clogging profile line parallel to the windward side inclination angle with a tangent circular arc;

[0098] a region identification module, connected to the clogging modeling module, configured to identify and distinguish the clogging region formed by the clogging material and the remaining cold gas efflux region in the radial circular cross section of the cylindrical film hole;

[0099] a model construction and selection module, connected to the region identification module, configured to call the first mathematical model or the second mathematical model according to the size relationship between the clogging material height and the original cylindrical film hole radius;

[0100] an aperture magnification factor calculation module, connected to the model construction and selection module, the core of which is to set an aperture magnification factor, and solve the factor through iterative calculation, so that the cold gas efflux area of the expanded cylindrical film hole after clogging is equal to the design cold gas efflux area of the original cylindrical film hole;

[0101] an iteration control and output module, connected to the aperture magnification factor calculation module, configured to control the convergence precision of the numerical iteration process, and when the relative deviation of the cold gas efflux area of the expanded cylindrical film hole after clogging and the design cold gas efflux area of the original cylindrical film hole is less than 1%, terminate the iteration and output the final aperture magnification factor, so as to determine the required aperture expansion diameter.

[0102] The present invention also proposes a turbine blade in which the cylindrical film cooling holes on the surface are designed using the aforementioned hole-enlarging design method for addressing blockage of cylindrical film cooling holes, so that even after the thermal barrier coating is applied and the cylindrical film cooling holes become blocked, they can still maintain a cold air outflow area and cooling performance comparable to the design stage.

[0103] This invention proposes a method for enlarging cylindrical film vents that is blocked. The method uses the Newton-Raphson iterative method to solve the nonlinear equations, quickly and accurately obtaining the aperture magnification factor, and ensuring that the deviation between the cold air outflow area after blockage and the original cylindrical film vent does not exceed 1%.

[0104] The above technical solution will be further described in detail below with reference to the accompanying drawings:

[0105] In one embodiment, a method for designing an enlarged orifice to address blockage of a cylindrical film gas vent includes the following steps:

[0106] Step 1: Refer to Figure 1 As shown, a method for modeling the blockage inside the spray-coated hole is established. The starting position of the blockage is located at the intersection of the vertical line from the upper end of the leeward side of the axial section of the cylindrical air film hole and the windward side. The original diameter of the cylindrical air film hole is 1.0 mm and the height of the blockage is 0.28 mm. The outline of the blockage is drawn parallel to the local windward side tilt angle. The starting position is connected to the outline of the blockage by a tangent circular arc to complete the modeling of the blockage inside the hole.

[0107] Step 2: Refer to Figure 2 As shown, the obstruction height in the radial circular cross-section of the cylindrical air film orifice is 0.28 mm. The circular cross-section presents two fan-shaped regions: the cold air outflow region and the obstruction region.

[0108] Step 3: The height of the blockage is less than the radius of the cylindrical air film orifice (h=0.28mm<R=0.5mm), and a mathematical model is established for the cold air outflow area and the angle of the blockage range (the angle between the two straight lines connecting the two ends of the blockage to the center of the circle).

[0109] The mathematical model for the angle of the cold air outflow area and the extent of the blockage is as follows:

[0110]

[0111] in, A The cold air outflow area is the original cylindrical air film orifice after it has been blocked by spray coating. R The radius of the original cylindrical air film pore. h The height of the blockage. α The angle of the obstruction;

[0112] Step 4: The cylindrical gas film hole after the aperture is enlarged has the same cold gas outflow area 0.785mm as the original cylindrical gas film hole after being blocked 2 , to ensure that the cooling performance of the cylindrical gas film hole after being blocked is equivalent to that in the design stage;

[0113] The same cold gas outflow area is expressed as follows:

[0114] A 2= A 1=0.785mm 2

[0115] wherein, A 1 is the design cold gas outflow area of the original cylindrical gas film hole, A 2 is the cold gas outflow area of the cylindrical gas film hole after the aperture is enlarged after being subjected to spraying and blocking;

[0116] Step 5: Under the premise that the cylindrical gas film hole structure adopts the aperture enlargement factor, the size relationship between the blocking height and the radius of the enlarged cylindrical gas film hole is determined, so as to select the mathematical model for calculating the aperture enlargement factor;

[0117] The size relationship between the blocking height and the blocking height threshold value is determined as follows:

[0118] The cylindrical gas film hole blocking height is h =0.28mm, which is less than The mathematical model for calculating the aperture enlargement factor is selected under the condition that the blocking height is less than the blocking height threshold value;

[0119] Step 6: According to the mathematical model of the cold gas outflow area and the blocking range angle in step 3, the equation group for calculating the aperture enlargement factor under the condition that is established;

[0120] The equation group for calculating the aperture enlargement factor under the condition that is as follows:

[0121] ;

[0122] wherein, is the aperture enlargement factor;

[0123] Step 7: and are substituted into the equation , so that the equation is obtained, and the aperture enlargement factor can be obtained by solving the equation;

[0124] The specific equation is as follows:

[0125] ;

[0126] Step 8: The equation contains inverse trigonometric functions and quadratic terms, and cannot obtain a theoretical solution. Newton-Raphson method is used to obtain the numerical solution of the equation by iteration;

[0127] The calculation process of Newton-Raphson method is as follows:

[0128] Function At the initial point , Taylor expansion is used:

[0129] ;

[0130] Let , that is:

[0131] ;

[0132] The next iteration point is obtained:

[0133] ;

[0134] This process is continuously iterated until the accuracy requirement is met:

[0135] ;

[0136] Step 9: Referring to the iteration termination condition of the aperture amplification factor shown in Figure 3 , 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;

[0137] The iteration termination condition of the aperture amplification factor is as follows:

[0138] The aperture amplification factor obtained by iteration calculation is =1.15, and the corresponding cold gas outflow area is A2=0.791mm2, which meets the accuracy requirement of iteration ;

[0139] Step 10: Referring to the flat plate gas film cooling calculation domain with a height of 0.28mm and the same cold gas outflow area as the original cylindrical gas film hole shown in Figure 4 , the blocking object modeling method and the aperture amplification factor in step 1 and step 9 are used to obtain the flat plate gas film cooling calculation domain;

[0140] Step 11: meshing and three-dimensional simulation calculation are performed on the flat plate gas film cooling calculation domain to obtain the flat plate gas film cooling distribution of the original, blocked and enlarged hole diameter and blocked flat plate gas film, specifically: the calculation domain is divided by tetrahedron unit, and irrelevance verification of meshing and relevant calculation condition setting are completed, wherein: the turbulent flow model is SST Gamma-Theta model, the main flow adopts velocity inlet and pressure outlet, the cooling gas adopts mass flow inlet, and the blowing ratio of the cooling gas is 0.5 and 1.0;

[0141] Step 12: as shown in Figure 5 and Figure 6 , the cylindrical gas film hole with blockage and enlarged hole diameter is obtained by the embodiment, and the gas film cooling effect and spanwise average gas film cooling effect of the original and blocked cylindrical gas film hole are compared, the negative effect of blockage on the gas film cooling under the blowing ratio of 0.5 is almost completely eliminated after the hole diameter is enlarged, and the blocked cylindrical gas film hole only has weak gas film cooling effect reduction under the blowing ratio of 1.0.

[0142] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments without departing from the principles and purposes of the present application within the scope of the present application.

Claims

1. A method for reaming design against plugging of cylindrical gas film orifices, characterized by, The method comprises the following steps: Step 1: determining the initial position, profile line and connection mode of the plug in the cylindrical gas film hole, and constructing a hole-plugging geometry model for spraying hole plugging; Step 2: identifying the influence area of the plug on the cold gas outflow in the radial circular cross section of the hole-plugging geometry model, dividing the circular cross section into a cold gas outflow area and a plug area, and establishing a mathematical model for calculating the cold gas outflow area; When the plug height is less than the original cylindrical gas film hole radius, a first mathematical model between the cold gas outflow area and the plug range angle is established; When the plug height is greater than or equal to the original cylindrical gas film hole radius, a second mathematical model between the cold gas outflow area and the plug range angle is established; Step 3: setting a hole diameter amplification factor, so that the cold gas outflow area of the cylindrical gas film hole after the hole diameter is expanded and the hole is plugged by spraying is equal to the designed cold gas outflow area of the original cylindrical gas film hole; Step 4: setting a plug height threshold, and according to the comparison result of the plug height threshold and the plug height, selecting the corresponding mathematical model of the cold gas outflow area and the plug range angle, and calculating 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, and the numerical solution of the hole diameter amplification factor is obtained; Step 7: judging whether the relative deviation of the cold gas outflow area of the cylindrical gas film hole after the hole diameter is expanded and the hole is plugged by spraying from the designed cold gas outflow area of the original cylindrical gas film hole is less than 1%, if yes, the calculation is terminated and the hole diameter amplification factor is output; if not, the iteration is continued until the accuracy requirement is met; Step 8: according to the finally obtained hole diameter amplification factor, the original cylindrical gas film hole is expanded and designed.

2. The method of reaming design for cylindrical gas film orifice plugging according to claim 1, wherein: The construction method of the hole-plugging geometry model for spraying hole plugging: the initial position of the plug is set at the intersection of the vertical line drawn downward from the upper end point of the leeward side of the axial cross section of the cylindrical gas film hole and the windward side, the plug height is the same as the coating thickness, the plug profile line parallel to the local windward side inclination angle is drawn, and the initial position and the plug profile line are connected by a tangent circular arc to complete the hole-plugging modeling.

3. The method of reaming design for a cylindrical gas film orifice plug according to claim 2, wherein: The first mathematical model is: wherein, A A0is the cold air outflow area of the original cylindrical gas film hole after experiencing spray clogging, R R0is the radius of the original cylindrical gas film hole, h H is the height of the clogging, α is the clogging range angle.

4. The method of reaming design for a cylindrical gas film orifice plug according to claim 3, wherein: The second mathematical model is: wherein, R R is the original cylindrical gas film hole radius, h H is the plug height, α A is the plug range angle.

5. The method of reaming design for a cylindrical gas film orifice plug according to claim 4, wherein: The rule for selecting the first mathematical model or the second mathematical model is: The clog height threshold is set to ; If then a first mathematical model is selected, and a calculated aperture magnification factor is obtained from the equation: If then a second mathematical model is selected to obtain a calculated aperture magnification factor The equation for the aperture magnification factor is as follows: wherein, 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 hole diameter is expanded and after the spray clogging is experienced.

6. The method of reaming design for a cylindrical gas film orifice plug according to claim 5, wherein: The aperture magnification factor The formula for calculating the aperture magnification factor is as follows: If , If , .

7. The method of reaming design for a cylindrical gas film orifice plug according to claim 6, wherein: The numerical iteration method is the Newton-Raphson method, and the iteration formula is: wherein is the aperture magnification factor value for the n th iteration, is the function first derivative at .

8. The method of reaming design for a cylindrical gas film orifice plug according to claim 7, wherein: The termination condition of the iteration is: wherein, 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 hole diameter is expanded and after experiencing spray clogging.

9. A system for designing a reaming operation for plugging a cylindrical gas film hole, performing the method for designing a reaming operation for plugging a cylindrical gas film hole according to any one of claims 1 to 8; characterized in that, It comprises: A plug modeling module is configured to establish a hole-plugging geometry model for spraying hole plugging according to the thermal barrier coating thickness, wherein the initial point of the plug is defined as the intersection of the vertical line drawn downward from the upper end point of the leeward side of the axial cross section of the cylindrical gas film hole and the windward side, and the point and the plug profile line parallel to the windward side inclination angle are connected by a tangent circular arc; A region identification module is connected with the plug modeling module and configured to identify and distinguish the plug region formed by the plug and the remaining cold gas outflow region in the radial circular cross section of the cylindrical gas film hole; A model construction and selection module is connected with the region identification module and configured to call the first mathematical model or the second mathematical model according to the size relationship between the plug height and the original cylindrical gas film hole radius. The aperture amplification factor calculation module is connected with the model construction and selection module, and its core is to set an aperture amplification factor, and the factor is solved through iterative calculation, so that after the hole is expanded, the cold gas outflow area of the cylindrical gas film hole after being blocked is equal to the designed cold gas outflow area of the original cylindrical gas 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 cylindrical gas film hole after being expanded in the aperture and the designed cold gas outflow area of the original cylindrical gas film hole is less than 1% after the spraying blockage is experienced, the iteration is terminated and the final aperture amplification factor is output, so as to determine the required expansion diameter.

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

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