Comprehensive cooling effect modeling method for turbine rotor blade of gas turbine engine

Abstract

The invention discloses a gas turbine engine turbine rotor blade comprehensive cooling effect modeling method which comprises the steps that key parameters concerned by the modeling method and forms of the key parameters are determined through theoretical derivation, the key parameters and the forms of the key parameters are arranged into an initial modeling correlation formula, the influence rule of the key parameters on the comprehensive cooling effect is obtained by conducting a test, and the comprehensive cooling effect is obtained. The form of each parameter in the whole initial modeling correlation is quantified and determined; based on the influence rule, determining the form of the key parameter in the initial modeling correlation formula, fitting to obtain the rule of the influence of the key parameter on the comprehensive cooling effect, converting the rule of the influence of the key parameter on the comprehensive cooling effect into a parameter correlation function in the initial modeling correlation formula, and after the research on the rule of the influence of all the parameters on the comprehensive cooling effect is completed, determining the comprehensive cooling effect. And integrating the functions to obtain a final modeling correlation. According to the method, a blade designer can be effectively helped to model the overall comprehensive cooling effect and on-way distribution of the turbine blade under the real rotation working condition.

Description

Technical Field

[0001] The invention relates to the technical field of cooling of turbine blades of aviation engines, and in particular to a comprehensive cooling effect modeling method for turbine rotor blades of gas turbine engines. Background Art

[0002] With the development of science and technology and industrial technology, the indicators of aircraft engines are also constantly improving. The current development trend is still focused on breakthroughs in high efficiency and high thrust. Since the main principle of aircraft engines is based on the Brayton cycle, increasing the temperature of the gas before the turbine can significantly improve the thermal efficiency and thrust-to-weight ratio, which is the main development direction. However, with the development of technology, countries around the world have raised the research and development requirements of the thrust-to-weight ratio to 20, and the turbine inlet temperature will reach 2273~2473K. The current turbine inlet temperature is significantly higher than the maximum temperature that the material can withstand.

[0003] Too high an inlet temperature can cause serious damage to the engine structure. To reduce damage to the blades, the main measures currently used are to raise the maximum temperature that the material can withstand or to use a cooling structure to reduce the wall temperature. The turbine inlet temperature has increased significantly with technological development, while the maximum temperature that high-temperature alloys can withstand has increased only to a limited extent. Therefore, in order to ensure the improvement of engine efficiency and thrust, it is necessary to continuously improve cooling technology.

[0004] In the exploration of blade cooling technology, experiments are the most important and accurate design and evaluation method. However, it is obvious that for aircraft engines, especially turbine blades, the high pressure and high temperature of the actual working conditions require great costs to implement and test for experimenters, and there are also great safety risks. Therefore, similarity theory is often used for modeling in experiments. That is, while ensuring that similar dimensionless numbers are equal, the high temperature and high pressure conditions of the actual working conditions are modeled to make them relatively easy to achieve in the laboratory. Relatively low temperature and low pressure conditions save costs while reducing risks.

[0005] Although similar theories are used in both domestic and foreign cooling efficiency tests to simulate real working conditions in the laboratory, the heat transfer characteristics of real working conditions at high temperature and high pressure are essentially different from those in the laboratory. Nowadays, experiments are often conducted using medium temperature and medium pressure conditions + modeling corrections. However, as the temperature before the turbine continues to increase, the working requirements and accuracy of the turbine blades are greatly improved. According to relevant literature, as long as the predicted value of the turbine blade working temperature deviates by 28K, it may shorten its service life by 1 / 2. However, at the current level, it is not possible to carry out real-condition turbine cooling efficiency tests for the following reasons:

[0006] (1) It is difficult to collect signals under high temperature conditions

[0007] Thermocouples cannot withstand high temperatures above 2000K. Although infrared radiation can achieve non-contact temperature measurement, the accuracy of infrared temperature measurement is far inferior to that of thermocouples. In addition, the pressure probe requires a water-cooling structure, but the water-cooling structure will reduce the detection accuracy.

[0008] (2) The structure cannot withstand high temperature conditions

[0009] At present, high-temperature materials generally have a temperature resistance of about 1350K. Even with a coating, they can only withstand a high temperature of 1450K, far from reaching 2000K. The current mainstream method is the water cooling jacket, which can solve the problem of material temperature resistance, but the material's own anti-oxidation problem brings about service life problems.

[0010] (3) The cost of the rotation state increases dramatically

[0011] Testing under high temperature and high pressure (temperature>2000K, pressure>3Mpa, rotation speed>10000rpm) conditions places extremely high demands on test components. Each test consumes a lot of water and electricity, which is very costly. In addition, the high-speed rotating blades will pose a great safety risk.

[0012] Based on the above reasons, it is currently unlikely to conduct experiments under real working conditions. Therefore, there is a need to conduct research on turbine cooling efficiency tests. After obtaining the accurate influence rules of key parameters, the test data under medium temperature and medium pressure conditions are used to obtain the high and low working condition modeling methods to accurately obtain the working effect of turbine blades under real working conditions.

[0013] There are two main test methods for medium temperature and medium pressure simulation tests: (1) cooling effect modeling correlation method; (2) engine operating condition simulation test method.

[0014] (1) Cooling effect test relationship method

[0015] This method is based on the model test research method, that is, according to the similarity theory, the actual target to be studied is modeled, and then the test is carried out on the test equipment. Next, the relationship between the similar parameters concerned in the similarity criterion can be derived generally through differential equation analysis or dimensional analysis, and these functional relationships are projected onto the actual target to be studied, thereby obtaining a method of obtaining the functional relationship between the parameters that are of interest in the actual target. Through heat transfer and modeling analysis, the test data of turbine blades with air-cooled structures have been organized and converted into correlation formulas to guide the test. This correlation formula for the test can be used to derive the cooling effect of turbine blades under any working condition of the engine. The general form is organized as follows:

[0016]

[0017] Where θ represents the relative cooling effect of the turbine blades, Tg Indicates the mainstream gas temperature, T w represents the turbine blade surface temperature, T c Indicates the cooling air temperature, K G Indicates the ratio of cooling air flow to gas flow; K T Represents the ratio of gas temperature to cooling air temperature; g It represents the Reynolds number on the gas side. After determining the values ​​of coefficient C and exponents n, z, and nm based on the test results, the cooling effect under any state can be calculated.

[0018] (2) Engine operating condition simulation test method

[0019] Similarity theory holds that when two physical phenomena of the same type simultaneously meet the four similarity conditions of geometric similarity, motion similarity, dynamic similarity, and thermal similarity, then the two phenomena of the same type can be considered to be similar. The engine operating condition simulation test method uses similarity theory as a theoretical basis, models the parameters of the actual engine operating conditions to medium-temperature and medium-pressure conditions according to the modeling criteria, and conducts experimental research on the comprehensive cooling effect of turbine blades under medium-temperature and medium-pressure conditions. After certain empirical corrections, the test results obtained can generally be considered to be consistent with the comprehensive cooling effect obtained under actual conditions. The key to the accurate simulation of this method is to propose an accurate modeling method to ensure that the medium-temperature and medium-pressure and high-temperature and high-pressure systems meet the similarity conditions.

[0020] However, the above-mentioned simulation methods are all for stationary conditions, and there is no simulation method applicable to rotating conditions. In the rotating state, simulation needs to study a variety of new influencing factors such as rotation speed and changes in inlet airflow angle. Because the traditional method lacks the simulation principle in this direction, it can only leave a margin to protect the highest temperature of the blade from ablation, but it will produce a large power loss. In addition, in the simulation experiment, due to different rotation speeds, there is no unified matching principle for the inlet airflow angle, which will cause the stagnation point to shift, resulting in a large deviation between the experimental results and the simulation results. Summary of the invention

[0021] The present invention proposes a comprehensive cooling effect modeling method for gas turbine engine turbine rotor blades to solve the problem that the existing modeling method for aircraft engine turbine rotating blades under static conditions cannot more effectively model the rotation speed and inlet airflow angle.

[0022] To achieve the above object, the present invention provides a method for modeling the comprehensive cooling effect of a gas turbine engine turbine rotor blade, comprising:

[0023] Through theoretical derivation, the key parameters and their forms of the modeling method are determined, and the parameters that have a greater impact on the comprehensive cooling effect include mainstream Reynolds number, mainstream to cold air flow ratio, and mainstream to cold air temperature ratio;

[0024] The key parameters and their forms are organized into an initial modeling correlation formula, and the influence of the key parameters on the comprehensive cooling efficiency is obtained by conducting several experiments, so as to quantitatively determine the form of each parameter in the entire initial modeling correlation formula, wherein the dependent variable of the initial modeling correlation formula is the comprehensive cooling efficiency of the blade, and the independent variable is each key parameter;

[0025] By theoretically deducing the rotation state, similar rotation speed is added as a new variable for the rotation condition of the rotor blades in the initial modeling correlation formula to obtain the final modeling correlation formula, and the influence of each parameter of flow ratio, temperature ratio and rotation speed on the comprehensive cooling effect is obtained through sensitivity analysis;

[0026] Based on the influence of each parameter on the comprehensive cooling efficiency, the form of the key parameter in the modeling correlation formula is determined, and the law of the influence of the key parameter on the comprehensive cooling efficiency is fitted, and the law of the influence of the key parameter on the comprehensive cooling efficiency is converted into a parameter-related function in the modeling correlation formula. After completing the study on the law of the influence of all parameters on the comprehensive cooling efficiency, the functions are integrated to obtain the final modeling correlation formula, that is, the modeling of the static comprehensive cooling efficiency result to the rotating result is realized, and a comprehensive cooling efficiency modeling method suitable for rotating turbine blades of aircraft engines is obtained.

[0027] Preferably, the key parameters concerned by the modeling method include: the mainstream Reynolds number, similar rotational speed, the temperature ratio and flow ratio of the cold air, and according to the test bench capability, the expression of similar rotational speed is processed differently for the two situations where the airflow angle can be guaranteed and the airflow angle cannot be guaranteed.

[0028] Preferably, the initial modeling association is:

[0029] θ=C(K G ) n (K T ) z (Re g ) n-m

[0030] In the formula, θ is the comprehensive cooling effect, C is a constant, K G is the flow ratio, K T is the temperature ratio, Re g is the mainstream Reynolds number, n is the influence index of flow ratio on the comprehensive cooling effect, z is the influence index of temperature ratio on the comprehensive cooling effect, and nm is the influence index of Reynolds number on the comprehensive cooling effect.

[0031] Preferably, after theoretical derivation of the rotation state, in addition to the flow ratio, temperature ratio, and Reynolds number, the speed-related dimensionless parameters are also included to select similar speeds. The rotation speed related dimensionless parameter is selected from the rotation linear velocity Mach number.

[0032] Preferably, obtaining the influence of the flow ratio, temperature ratio and rotation speed parameters on the comprehensive cooling effect includes:

[0033] A sensitivity analysis was performed on the temperature ratio, the flow ratio and the similar rotation speed, and the influence on the comprehensive cooling efficiency was obtained from large to small, namely, flow ratio, similar rotation speed and temperature ratio.

[0034] Preferably, the final modeling association is:

[0035] θ=C(K G ) n (K T ) z (Re g ) n-m F(K N )

[0036] In the formula, F(K N ) is a mathematical expression for the influence of similar rotation speed on the comprehensive cooling efficiency.

[0037] Compared with the prior art, the present invention has the following advantages and technical effects:

[0038] (1) The present invention has carried out relevant research on the rotating comprehensive cooling effect modeling method, and has carried out sensitivity analysis and other methods on the key parameters and matching principles of the rotating modeling that have not been carried out at home and abroad, and obtained a modeling method for the rotating working conditions of aircraft engines. Compared with the previous static modeling method, this method has carried out in-depth research on the inlet airflow angle and rotation speed, and has discovered similar rotation speed and mid-section inlet airflow angle as new parameters of the rotating working conditions to study their form in the modeling correlation equation.

[0039] (2) The present invention effectively realizes the modeling between working conditions under the rotating state, greatly reducing the modeling error. Previously, due to the lack of a modeling method applicable to the rotating state, the experiments did not match similar rotation speeds with inlet airflow angles. The domestic design also adopted the method of increasing the margin to prevent the blades from burning too quickly. However, because of the impact of the change in the inlet airflow angle, the comprehensive cooling effect distribution trend along the process obtained has a large error, which will lead to a large deviation in the positioning of the high-temperature zone of the blade during the design, resulting in a lack of protection measures in the areas that need to be protected, and the main protection measures (such as the air film hole outflow design) are given to relatively unimportant areas.

[0040] (3) The present invention can effectively help blade designers simulate the overall comprehensive cooling effect and its distribution along the turbine blade under the actual rotation condition, and help locate the highest temperature point, thereby extending the blade life, reducing damage, and reducing power waste caused by margin. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0042] Figure 1 A flow chart of a method for modeling the comprehensive cooling effect of a turbine rotor blade of a gas turbine engine according to an embodiment of the present invention;

[0043] Figure 2 This is a sensitivity analysis diagram of temperature ratio, flow ratio, Biot number and rotation speed according to an embodiment of the present invention;

[0044] Figure 3 1 is a diagram of the distribution of the comprehensive cooling effect along the middle section at different speeds of an embodiment of the present invention, wherein (a) is a schematic diagram of a comparative working condition, (b) is a schematic diagram of the comprehensive cooling effect distribution at 600 rpm, (c) is a schematic diagram of the comprehensive cooling effect distribution at 8000 rpm, and (d) is a schematic diagram of the comprehensive cooling effect distribution at 10000 rpm;

[0045] Figure 4 This is a curve diagram of the comprehensive cooling efficiency changing with the Reynolds number according to an embodiment of the present invention. DETAILED DESCRIPTION

[0046] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0047] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0048] Terminology explanation:

[0049] Comprehensive cooling efficiency: A dimensionless parameter to measure the cooling effect of turbine blades. Its physical meaning is the difference between the mainstream gas and the blade surface temperature divided by the difference between the mainstream gas and the cold air temperature. Its value is between 0 and 1. The closer the value is to 1, the better the cooling effect of the blade, and vice versa.

[0050] Modeling method: A method based on similarity theory to simulate real high-temperature working conditions to medium / low-temperature working conditions. After ensuring geometric similarity, dynamic similarity, motion similarity and thermal similarity, it can be considered that the simulated working conditions are similar to the flow and heat exchange of the real working conditions. Therefore, it is often used to simulate the comprehensive cooling effect of the real engine working conditions.

[0051] Modeling correlation formula: During the test, it is impossible to ensure that all dimensionless parameters match the actual working conditions. Therefore, it is necessary to find out the influence of the parameters that cannot be met on the comprehensive cooling efficiency results. All influencing parameters are classified into a correlation formula, which is the modeling correlation formula. When a certain parameter cannot be matched, the influence of the parameter on the comprehensive cooling efficiency can be calculated through the influence of the parameter on the comprehensive cooling efficiency when the parameter cannot be matched. The influence of the parameter on the comprehensive cooling efficiency is used as a correction coefficient. The comprehensive cooling efficiency result of the test is multiplied by the correction coefficient and it can be considered to be the same as the comprehensive cooling efficiency result of the actual working conditions.

[0052] Moving blade inlet airflow angle: the angle between the moving blade inlet airflow direction and the turbine axis direction.

[0053] Since most guide vanes are twisted blades, it is often impossible to ensure that the inlet airflow angle of each section is completely matched in the experiment. Therefore, it is necessary to analyze which blade height inlet airflow angle can ensure the minimum deviation of the comprehensive cooling efficiency. By similarly matching the speed and the inlet airflow angle, the modeling error of the turbine blades in the rotating state is greatly improved, while ensuring that the comprehensive cooling efficiency along the process is basically consistent with the original working condition trend.

[0054] This embodiment provides a method for modeling the comprehensive cooling effect of a turbine rotor blade of a gas turbine engine (eg Figure 1 ), while ensuring the modeling error of the overall comprehensive cooling effect and the distribution trend of the comprehensive cooling effect along the process, so as to improve the accuracy of the design and test of aircraft engine turbine blades, and enhance the design and test capabilities of aircraft engine turbine blades in my country, including:

[0055] Based on the existing related research, theoretical deduction is carried out to establish the initial modeling correlation formula:

[0056]

[0057] The above relationship is an existing modeling correlation method for static working conditions, but its limitation is that it does not take into account the influence of the rotating state. Therefore, the previous modeling correlation method is supplemented by adding a similar parameter of the speed.

[0058] During the test, the speed similarity parameter positioning K N , which is based on similar speeds. However, in the static test, the speed is 0, so K N A simple definition of similar speed will make the calculation result of comprehensive cooling efficiency under static condition equal to 0, which is incorrect. Therefore, in order to prevent the universality of the relationship from being reduced, when calculating the influence of similar speed parameters, the comprehensive cooling efficiency result under static condition is taken as the benchmark, and the comprehensive cooling efficiency results under different speeds are divided by the comprehensive cooling efficiency under static condition to obtain a ratio, which is used as F(K N ) value, due to F(K N) is close to a quadratic function, so this method effectively avoids the problem that the correlation is invalid when the speed is 0. For a quadratic function, there will be a problem of being less than 0. It has been observed that when this parameter is less than 0, the similar speed is extremely large, and it is difficult to reach this value in the test and the actual working conditions of the engine, so this method is feasible.

[0059] The final modular association is formed:

[0060] θ=C(K G ) n (K T ) z (Re g ) n-m F(K N )

[0061] In the formula, F(K N ) is a mathematical expression for the influence of similar rotation speed on the comprehensive cooling efficiency.

[0062] Compared with the existing achievements, which mainly simulate static conditions, there are few simulation methods for rotating conditions at home and abroad. Therefore, this embodiment can focus on the modeling problems of rotation speed and inlet airflow angle that the existing methods cannot simulate, and effectively improve the problem that the real rotating conditions cannot be effectively simulated during the test and design process. The influence degree and influence law of each parameter on the comprehensive cooling effect are clarified, and the comprehensive cooling effect modeling error is greatly reduced, providing a more accurate comprehensive cooling effect modeling principle for the design of aircraft engine turbine blades.

[0063] Furthermore, the key parameters include: the mainstream Reynolds number, similar rotation speed, the temperature ratio and flow ratio of the cold air, and whether to ensure the inlet airflow angle is selected according to the capability of the test bench itself.

[0064] Furthermore, based on the modeling correlation formula, the test bench capability is analyzed. If the guide vane angle, that is, the blade inlet airflow angle, can be adjusted, then in subsequent tests, the blade inlet airflow angle under the test conditions will be kept consistent with the blade inlet airflow angle under the set comparison conditions, thereby obtaining a comprehensive cooling efficiency modeling method suitable for rotating turbine blades of aircraft engines.

[0065] If it cannot be adjusted, then based on the study of the change of the comprehensive cooling effect of turbine blades with the speed, it is found that the change of speed will cause the change of the comprehensive cooling effect of the blades to show opposite trends on the pressure side and the suction side, such as Figure 3 (a)- Figure 3 As shown in (d), the comprehensive cooling effect is divided into the comprehensive cooling effect of the pressure surface and the comprehensive cooling effect of the suction surface, and the comprehensive cooling effect correlation formula of the two surfaces is obtained, including: the suction surface and the pressure surface;

[0066] The suction surface is:

[0067] θs =C(K G ) n (K T ) z (Re g ) n-m F S (K N )

[0068] In the formula, θ s is the average comprehensive cooling efficiency of the suction surface, F S (K N ) is the influence of similar rotation speed of suction surface on comprehensive cooling efficiency;

[0069] The pressure surface is:

[0070] θ c =C(K G ) n (K T ) z (Re g ) n-m F C (K N )

[0071] In the formula, θ c is the average comprehensive cooling effect of the pressure surface, F C (K N ) is the influence of similar rotation speed on the pressure surface on the comprehensive cooling effect.

[0072] For the flow ratio, temperature ratio and mainstream Reynolds number, the index is obtained as follows:

[0073] For each parameter, multiple tests were carried out separately. Only one of the above parameters was changed, and the others remained unchanged. At this time, the influence of each parameter change on the comprehensive cooling efficiency can be obtained. Then the influence law is quantified. The parameter change is taken as the X-axis and the comprehensive cooling efficiency change is taken as the Y-axis. The data is defined as the point in the coordinate system and fitted into an exponential function. The exponent of the function is the exponent of the parameter in the correlation equation.

[0074] Taking the Reynolds number as an example, four groups of working conditions are set, and only the main gas Reynolds number is changed. The ratios of the main gas Reynolds number to the original working condition are 0.6, 0.8, 1.2, and 1.4 respectively. The comprehensive cooling effect is shown in Table 1 below:

[0075] Table 1

[0076] Ratio of Reynolds number to original working condition Comprehensive cooling effect 0.6 0.9337 0.8 0.9581 1.2 1.0303 1.4 1.0561

[0077] The exponential function curve is obtained by fitting, such as Figure 4 As shown, the curve index is 0.15, corresponding to the target blade index nm=0.15.

[0078] For similar speeds, multiple tests were conducted to obtain the influence law of similar speeds and comprehensive cooling efficiency, which was then fitted into a polynomial, which is the form of the similar speed in the correlation equation.

[0079] Finally, a comprehensive cooling efficiency modeling method suitable for rotating turbine blades of aircraft engines is obtained. By changing the test conditions, the difference between the comprehensive cooling efficiency prediction value based on the present invention and the simulation value is only 3%, and the calculation accuracy is high.

[0080] In order to more clearly express the technical solution of the present invention, the following specific embodiments are provided to introduce the solution:

[0081] Step 1: Determine the test process based on whether the guide vane angle can be adjusted on the test bench. If the guide vane can be adjusted, the guide vane angle should be adjusted to ensure the rotor blade inlet airflow angle of the test condition.

[0082] If the guide vane angle cannot be adjusted, then due to the different influence trends of the rotational speed on the pressure surface and the suction surface, the pressure surface and the suction surface should be considered separately in subsequent tests on the rotational speed. The pressure surface refers to the surface on the blade where the fluid flow is subjected to pressure, that is, the convex surface of the blade. The suction surface refers to the surface on the blade where the fluid flow is subjected to suction, that is, the concave surface of the blade.

[0083] Step 2. Based on step 1, design a set of test conditions with matching airflow angles at the inlet of the moving blades on the test bench. The conditions do not need to be similar to the actual conditions, and set multiple sets of comparison conditions. Each comparison condition only changes one of the mainstream Reynolds number, temperature ratio, flow ratio and similar speed relative to the test condition, and the parameters involved in the test and the ratio of the change parameters of each comparison condition to the test condition parameters are calculated, and the comprehensive cooling effect ratio is combined to form a curve graph of the comprehensive cooling effect changing with the key parameters, and fit it to an exponential function, and solve its index, which is the influence index of the key parameter. Taking the mainstream Reynolds number as an example, set multiple conditions, each condition only changes the mainstream Reynolds number, and set the ratio of the mainstream Reynolds number of each condition to the mainstream Reynolds number of the test condition as the X-axis, and the ratio of the comprehensive cooling effect to the comprehensive cooling effect of the test condition as the Y-axis, so as to form a curve graph with the mainstream Reynolds as the independent variable and the comprehensive cooling effect as the dependent variable, and fit it to obtain the influence index of the Reynolds number on the comprehensive cooling effect. Finally, the influence indexes of multiple key parameters are integrated to form a modeled correlation formula:

[0084] θ=C(K G ) n (K T ) z (Re g ) n-m F(K N )

[0085] like Figure 2It is an analysis diagram for the sensitivity of temperature ratio, flow ratio, Biot number and speed, where operating conditions 1-2 are temperature ratio sensitivity, 3-4 are flow ratio sensitivity, 5-6 are Biot number sensitivity, and 7-11 are speed sensitivity.

[0086] If the inlet airflow angle cannot be guaranteed in step 2, then the test results should be statistically analyzed for the pressure side and the suction side respectively to obtain the suction side modeling correlation formula:

[0087] θ s =C(K G ) n (K T ) z (Re g ) n-m F S (K N )

[0088] Pressure surface model correlation:

[0089] θ c =C(K G ) n (K T ) z (Re g ) n-m F C (K N )

[0090] Step 3: Set up test conditions based on the test methods of each experimental team. The test conditions are mainly to ensure that the conditions are most similar to the actual conditions, and then carry out the test.

[0091] Step 4: Correct the dimensionless parameters that cannot be satisfied in the test conditions determined in step 3.

[0092] Taking the Reynolds number as an example, when other parameters are guaranteed under the test conditions but the mainstream Reynolds number cannot be guaranteed, the comprehensive cooling efficiency results of the actual conditions will inevitably differ from the test conditions. The actual conditions are defined as condition 1 and the test conditions are defined as condition 2. The test results can be corrected using the following correlation formula to obtain a comprehensive cooling efficiency value that is closer to the actual results:

[0093]

[0094] In the formula, θ 1 is the comprehensive cooling effect result under actual working conditions, θ 2 is the comprehensive cooling effect result of the test condition, Re g1 is the mainstream Reynolds number under real working conditions, Re g2 is the mainstream Reynolds number of the test condition.

[0095] In this way, the correction of the comprehensive cooling efficiency can be completed, and the final comprehensive cooling efficiency value is closest to the comprehensive cooling efficiency under actual working conditions.

[0096] The above are only preferred specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for modeling the comprehensive cooling effect of a gas turbine engine turbine rotor blade, characterized in that: include: Through theoretical derivation, the key parameters and their forms of the modeling method are determined, and the parameters that have a greater impact on the comprehensive cooling effect include mainstream Reynolds number, mainstream to cold air flow ratio, and mainstream to cold air temperature ratio; The key parameters and their forms are organized into an initial modeling correlation formula, and the influence of the key parameters on the comprehensive cooling efficiency is obtained by conducting several experiments, so as to quantitatively determine the form of each parameter in the entire initial modeling correlation formula, wherein the dependent variable of the initial modeling correlation formula is the comprehensive cooling efficiency of the blade, and the independent variable is each key parameter; By theoretically deducing the rotation state, similar rotation speed is added as a new variable for the rotation condition of the rotor blades in the initial modeling correlation formula to obtain the final modeling correlation formula, and the influence of each parameter of flow ratio, temperature ratio and rotation speed on the comprehensive cooling effect is obtained through sensitivity analysis; Based on the influence of each parameter on the comprehensive cooling efficiency, the form of the key parameter in the modeling correlation formula is determined, and the law of the influence of the key parameter on the comprehensive cooling efficiency is fitted, and the law of the influence of the key parameter on the comprehensive cooling efficiency is converted into a parameter-related function in the modeling correlation formula. After completing the study on the law of the influence of all parameters on the comprehensive cooling efficiency, the functions are integrated to obtain the final modeling correlation formula, that is, the modeling of the static comprehensive cooling efficiency result to the rotating result is realized, and a comprehensive cooling efficiency modeling method suitable for rotating turbine blades of aircraft engines is obtained.

2. The method for modeling the comprehensive cooling effect of a gas turbine engine turbine rotor blade according to claim 1, characterized in that: The key parameters that the modeling method focuses on include: mainstream Reynolds number, similar speed, temperature ratio and flow ratio of cold air. Based on the test bench capability, the expression of similar speed is processed differently for the two situations where the airflow angle can be guaranteed and the airflow angle cannot be guaranteed.

3. The method for modeling the comprehensive cooling effect of a gas turbine engine turbine rotor blade according to claim 1, characterized in that: The initial modeling association is: θ=C(K G ) n (K T ) z (Re g ) n-m In the formula, θ is the comprehensive cooling effect, C is a constant, K G is the flow ratio, K T is the temperature ratio, Re g is the mainstream Reynolds number, n is the influence index of flow ratio on the comprehensive cooling effect, z is the influence index of temperature ratio on the comprehensive cooling effect, and nm is the influence index of Reynolds number on the comprehensive cooling effect.

4. The method for modeling the comprehensive cooling effect of a gas turbine engine turbine rotor blade according to claim 1, characterized in that: After theoretical derivation of the rotation state, in addition to the flow ratio, temperature ratio, and Reynolds number, the speed-related dimensionless parameters are also included to select similar speeds. The rotation speed related dimensionless parameter is selected from the rotation linear velocity Mach number.

5. The method for modeling the comprehensive cooling effect of a gas turbine engine turbine rotor blade according to claim 4, characterized in that: Obtain the influence of flow ratio, temperature ratio and speed parameters on the comprehensive cooling effect, including: A sensitivity analysis was performed on the temperature ratio, the flow ratio and the similar rotation speed, and the influence on the comprehensive cooling efficiency was obtained from large to small, namely, flow ratio, similar rotation speed and temperature ratio.

6. The method for modeling the comprehensive cooling effect of a gas turbine engine turbine rotor blade according to claim 1, characterized in that: The final modeling association is: θ=C(K G ) n (K T ) z (Re g ) n-m F(K N ) In the formula, F(K N ) is a mathematical expression for the influence of similar rotation speed on the comprehensive cooling efficiency.

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