Method for establishing evaluation model of maximum air intake of compressor and evaluation method

Abstract

This invention discloses a method for establishing and evaluating a model for assessing the maximum bleed air volume of a compressor. The method for establishing the assessment model includes the following steps: establishing a model formula for assessing the maximum bleed air volume of the compressor; obtaining sufficient data from the interface of the bleed air test specimen for assessing the maximum bleed air volume of the compressor, extracting existing influencing factors and their corresponding maximum bleed air volumes, and dividing the data into a derivation dataset, a correction dataset, and a verification dataset; substituting the data from the derivation dataset into the model formula to obtain an initial model for the maximum bleed air volume of the compressor; substituting the data from the correction dataset into the initial model to correct the model to obtain a corrected model; and substituting the data from the verification dataset into the corrected model for verification to determine the final assessment model. The assessment model established by the method of this invention can more accurately assess the bleed air volume of compressor test specimens under limited data support.

Description

Technical Field

[0001] This invention relates to the field of aero-engine testing, specifically to a method for establishing and evaluating an evaluation model for the maximum bleed air volume of a compressor. Background Technology

[0002] Compressor performance testing is a crucial step in the development of aero-engines. Bleed air testing is a mandatory component of compressor performance testing. An appropriate bleed air ratio can increase the compressor surge margin and improve its aerodynamic performance. The data from this test provides vital support for the research and optimization of the entire aero-engine and its core components. Furthermore, during aero-engine ignition and startup, to prevent compressor surge caused by a sudden increase in compressor back pressure, the bleed air ratio needs to be appropriately increased. The corresponding changes in the bleed air ratio must be tested during the compressor performance testing process.

[0003] To ensure the smooth conduct of bleed air tests, the maximum bleed air volume of the compressor must be assessed during the aero-engine test preparation phase to confirm the conditions that can be met during the test. Furthermore, the estimation of bleed air volume sometimes determines the technical requirements of the corresponding hardware interface dimensions and connection methods of the test piece and equipment, which directly affects the configuration of the aero-engine compressor test piece. Therefore, accurate and effective methods for bleed air volume assessment are extremely important.

[0004] During the test specimen design process, the maximum bleed capacity of the test specimen under various operating conditions is evaluated by calculating the air flow characteristics based on the bleed port of the test specimen and the bleed position status parameters before the test. This method has a large evaluation error, cannot assess the actual flow state, and cannot effectively assess the losses caused to the test specimen structure during compressor bleed. With the development of numerical simulation technology, calculating the bleed outlet flow state of the test specimen using numerical simulation is also one of the current methods for evaluating the maximum bleed capacity. However, this method does not integrate the test apparatus and the test specimen together, resulting in large calculation errors. If the test specimen and the test apparatus are integrated into a unified model for calculation, the evaluation accuracy can be improved, but the preparation and calculation time is longer, increasing the test preparation cycle and causing additional test costs. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the existing technology in evaluating the maximum bleed air volume of aero-engine compressors, which has large evaluation errors and long evaluation time. The present invention provides a method for establishing an evaluation model for the maximum bleed air volume of a compressor and an evaluation method thereof.

[0006] The present invention solves the above-mentioned technical problems through the following technical solution:

[0007] This invention provides a method for establishing an evaluation model for the maximum bleed air volume of a compressor, comprising the following steps:

[0008] S1. Establish a model formula for evaluating the maximum bleed air volume of the compressor. The model formula is as follows:

[0009] M=A(f(x1)+b1)(f(x2)+b2)···(f(xi)+bi);

[0010] In the formula: M is the maximum bleed air volume in the final evaluation, parameter A is the total influence coefficient of the evaluation model, xi is the influence factor of the maximum bleed air volume of the compressor, f(xi) is the underlying function of each influence factor, and bi is the correction coefficient of each influence factor.

[0011] S2. Obtain sufficient data from the bleed air test specimen interface to evaluate the maximum bleed air volume of the compressor, extract possible influencing factors and corresponding maximum bleed air volume M, and divide the data into derivation dataset, correction dataset, and verification dataset.

[0012] S3. Substitute the data from the derivation dataset obtained in step S2 into the model formula to obtain the underlying function f(xi), correction coefficient bi and parameter A of each influencing factor of the compressor's maximum bleed air volume, and obtain the initial model of the compressor's maximum bleed air volume.

[0013] S4. Substitute the data from the corrected dataset in step S2 into the obtained initial model to correct the model and obtain the corrected model.

[0014] S5. Substitute the data in the verification dataset into the correction model and determine whether the calculation error of the verification data is greater than the error requirement value C. If the calculation error is not greater than the error requirement value C, the correction model obtained in step S4 is the final evaluation model of the compressor's maximum bleed air volume. If the calculation error of the verification data is greater than the error requirement value C, return to step S3 to obtain a new initial model, and then obtain a new correction model through step S4 before executing step S5. Repeat this iterative process until the correction model meets the error requirement.

[0015] In this scheme, the method for establishing the evaluation model of the maximum bleed air volume of the compressor can be used to establish a general evaluation model of the bleed air volume of aero-engines. It can more accurately complete the evaluation of the bleed air volume of the compressor test piece under the condition of limited data support. The method effectively integrates the influencing factors of the test piece and the test instrument, making the evaluation model more accurate in evaluating the compressor bleed air volume. Moreover, the obtained evaluation model is universal and can be used repeatedly, which greatly reduces the difficulty and cost of compressor bleed air evaluation and provides better results for aero-engine compressor bleed air testing.

[0016] Preferably, step S2 includes the following steps:

[0017] S21. Determine whether the data obtained through the experiment for establishing the evaluation model of the maximum bleed air volume of the compressor is sufficient; if sufficient, proceed to step S3; if insufficient, proceed to step S22 below.

[0018] S22. Obtain data for establishing an evaluation model of the maximum bleed air volume of the compressor through numerical simulation, and combine this data with some data obtained through experiments into the derivation dataset. The remaining data obtained through experiments are combined into the correction dataset and the verification dataset.

[0019] In this approach, when experimental data is insufficient, partial data is obtained through numerical simulation and used only for model building, rather than directly for air entrainment assessment. This allows for the rapid establishment of an air entrainment assessment model without the need for multiple experiments to obtain data or repeated modeling calculations, thus reducing time consumption and significantly lowering costs.

[0020] Preferably, in step S5, the calculation error of the verification data is defined as follows, assuming the influence factors are the same within the verification dataset: (model calculation flow - test flow) / test flow.

[0021] In this scheme, the calculation error of the verification data is determined to determine whether the established evaluation model meets the requirements, so as to avoid too much deviation between the evaluation data and the actual induced gas flow rate data.

[0022] Preferably, the derived dataset, the corrected dataset, and the verification dataset are all distributed across the entire range of data.

[0023] In this approach, the derivation dataset, the correction dataset, and the validation dataset are all distributed across the entire data range, ensuring the reliability of the final evaluation model and making the evaluation results more accurate.

[0024] Preferably, the verification dataset is randomly selected from the data obtained through experiments and is distributed across the entire range of the data.

[0025] In this approach, the validation dataset is randomly selected from the data obtained through experiments, further ensuring the reliability of the final evaluation model and making the evaluation results more accurate.

[0026] Preferably, the factors affecting the maximum bleed air volume of the compressor include the compressor bleed port pressure, the bleed port cross-sectional area, and the airflow temperature.

[0027] Preferably, the underlying function f(xi) of each influencing factor of the compressor's maximum bleed air volume is obtained by the controlled variable method.

[0028] In this scheme, by controlling the variables and keeping other influencing factors constant, we first find the underlying function f(xi) of a certain influencing factor, substitute it into the model, and solve it easily, effectively reducing the difficulty of calculation and derivation.

[0029] The present invention also provides a method for evaluating the maximum bleed air volume of a compressor, the evaluation method comprising the following steps:

[0030] An evaluation model for the maximum bleed air volume of a compressor is established using the method described above.

[0031] Obtain the parameters of each influencing factor on the maximum bleed air volume of the compressor;

[0032] By substituting the parameters of each influencing factor of the compressor's maximum bleed air volume into the evaluation model, the compressor's maximum bleed air volume can be obtained.

[0033] In this scheme, the established bleed air volume assessment model can quickly assess the compressor bleed air volume and evaluate the actual flow state caused by the compressor. It has low error, short preparation time, reduces the difficulty and cost of compressor bleed air assessment, and ensures the smooth conduct of aero-engine compressor bleed air tests.

[0034] The positive and progressive effects of this invention are as follows: the method for establishing an evaluation model for the maximum bleed air volume of a compressor can be used to establish a general evaluation model for the bleed air volume of aero-engines, enabling more accurate evaluation of the bleed air volume of compressor test pieces even with limited data support; this method effectively integrates the influencing factors of the test piece and the test instrument, making the evaluation model more accurate in evaluating the compressor bleed air volume; furthermore, the obtained evaluation model is universal and can be used repeatedly, greatly reducing the difficulty and cost of compressor bleed air evaluation, and providing better results for aero-engine compressor bleed air testing. Attached Figure Description

[0035] Figure 1 This is a flowchart illustrating the method for establishing an evaluation model for the maximum bleed air volume of a compressor, which is a preferred embodiment of the present invention.

[0036] Figure 2 This is a flowchart of a method for evaluating the maximum bleed air volume of a compressor in an embodiment of the present invention. Detailed Implementation

[0037] The present invention will be further illustrated by way of embodiments below, but the present invention is not limited to the scope of the following embodiments.

[0038] like Figure 1 As shown, a method for establishing an evaluation model for the maximum bleed air volume of a compressor according to an embodiment of the present invention includes the following steps:

[0039] S1. Establish a model formula for evaluating the maximum bleed air volume of the compressor. The model formula is as follows:

[0040] M=A(f(x1)+b1)(f(x2)+b2)···(f(xi)+bi).

[0041] In the formula: M is the maximum bleed air volume for final evaluation; parameter A is the total influence coefficient of the evaluation model; xi is the influence factor of the maximum bleed air volume of the compressor; f(xi) is the underlying function of each influence factor. This function f(xi) is a simple function such as linear, exponential, logarithmic, or polynomial, and there is no complex transformation of the influence factors; bi is the correction coefficient of each influence factor, which is used to improve the accuracy of the evaluation model.

[0042] S2. Obtain sufficient data from the bleed air test specimen interface to evaluate the maximum bleed air volume of the compressor, extract possible influencing factors and corresponding maximum bleed air volume M, and divide the data into derivation dataset, correction dataset, and verification dataset.

[0043] S3. Substitute the data from the derivation dataset obtained in step S2 into the model formula to obtain the underlying function f(xi), correction coefficient bi and parameter A of each influencing factor of the compressor's maximum bleed air volume, and obtain the initial model of the compressor's maximum bleed air volume.

[0044] S4. Substitute the data from the corrected dataset in step S2 into the obtained initial model to correct the model and obtain the corrected model.

[0045] S5. Substitute the data in the verification dataset into the correction model and determine whether the calculation error of the verification data is greater than the error requirement value C. If the calculation error is not greater than the error requirement value C, the correction model obtained in step S4 is the final evaluation model of the compressor's maximum bleed air volume. If the calculation error of the verification data is greater than the error requirement value C, return to step S3 to obtain a new initial model, and then obtain a new correction model through step S4 before executing step S5. Repeat this iterative process until the correction model meets the error requirement.

[0046] The method for establishing the maximum bleed air volume assessment model of this compressor can be used to establish a general bleed air volume assessment model for aero-engines. It enables more accurate assessment of the bleed air volume of compressor test pieces even with limited data support. This method effectively integrates the influencing factors of the test piece and the testing equipment, making the assessment model more accurate in evaluating the compressor bleed air volume. Furthermore, the obtained assessment model is universal and can be used repeatedly, greatly reducing the difficulty and cost of compressor bleed air assessment and providing better results for aero-engine compressor bleed air testing. The implementation order of steps S1 and S2 is not restricted here; they can be performed simultaneously or sequentially.

[0047] In this embodiment, step S2 includes the following steps:

[0048] S21. Determine whether the data obtained through the experiment for establishing the evaluation model of the maximum bleed air volume of the compressor is sufficient; if sufficient, proceed to step S3; if insufficient, proceed to step S22 below.

[0049] S22. Obtain data for establishing an evaluation model of the maximum bleed air volume of the compressor through numerical simulation, and combine this data with some data obtained through experiments into the derivation dataset. The remaining data obtained through experiments are combined into the correction dataset and the verification dataset.

[0050] When experimental data is insufficient, numerical simulation can be used to obtain partial data, which is then used solely for model building rather than directly for air-entraining assessment. This allows for the rapid establishment of an air-entraining assessment model without the need for multiple experiments to obtain data or repeated modeling calculations, resulting in lower time consumption and significantly reduced costs. Numerical simulation can be performed using a computer employing the finite difference method or the finite element method. Of course, if the experimental data is sufficient to support model building, numerical simulation calculations may not be necessary.

[0051] The data obtained from numerical simulation can only be used as a derivation dataset. The established evaluation model for induced air volume needs to be corrected and verified using experimental data.

[0052] In step S5, the calculation error of the verification data is defined as follows, assuming the influencing factors are the same within the verification dataset: (model calculated flow rate - experimental flow rate) / experimental flow rate. Determining the calculation error of the verification data helps determine whether the established evaluation model meets the requirements, avoiding excessive deviation between the evaluation data and the actual induced draft flow rate data.

[0053] Use the verification dataset to check the air volume calculation model in step S4. The calculation error of all verification data must be less than or equal to the required value C. Otherwise, obtain a new initial model based on the data of the derivation dataset, change the correction reference point and increase the revision accuracy to obtain a new corrected model, and then perform verification until the model meets the error requirements.

[0054] In this embodiment, the derived dataset, the corrected dataset, and the verification dataset must all be distributed across the entire range of data. This ensures the reliability of the final evaluation model and makes the evaluation results more accurate.

[0055] The validation dataset is randomly selected from the data obtained through experiments and is distributed across the entire data range. Random selection of the validation dataset further ensures the reliability of the final evaluation model and makes the evaluation results more accurate.

[0056] The influencing factors of the compressor's maximum bleed air volume include the compressor's bleed port pressure, bleed port cross-sectional area, and gas flow temperature. The underlying function f(xi) of each influencing factor of the compressor's maximum bleed air volume is obtained using the controlled variable method. By using the controlled variable method, under the condition that other influencing factors remain constant, the underlying function f(xi) of a certain influencing factor is first identified, substituted into the model, and the solution is easy, effectively reducing the difficulty of calculation and derivation. The compressor's maximum bleed air volume may also have other influencing factors; their underlying functions and correction coefficients can be obtained using the controlled variable method and substituted into the model formula to increase the accuracy of the evaluation model.

[0057] The underlying function f(xi) corresponding to each influencing factor xi may differ, and each influencing factor should be independent and not affect each other. The simple functions of the existing influencing factors in the model can be used, which represents the general rule of the influence of each influencing factor on the assessment of maximum induced draft.

[0058] It should be noted that, with the bleed air system of the compressor test chamber for aero-engines remaining unchanged, the evaluation model for the maximum bleed air volume of the compressor obtained in this invention is universal. Therefore, the evaluation model of this invention can achieve the evaluation of the maximum bleed air volume for all test pieces using a very small number of bleed air volume models. The evaluation model established using the above-described method for establishing the evaluation model for the maximum bleed air volume of the compressor can be continuously corrected during the accumulation of test data, thereby improving the evaluation accuracy.

[0059] like Figure 2 As shown, the present invention also provides a method for evaluating the maximum bleed air volume of a compressor, the evaluation method comprising the following steps:

[0060] S10. Establish an evaluation model for the maximum bleed air volume of the compressor using the method described above.

[0061] S20. Obtain the parameters of each influencing factor of the compressor's maximum bleed air volume;

[0062] S30. By substituting the parameters of each influencing factor of the compressor's maximum bleed air volume into the evaluation model, the compressor's maximum bleed air volume can be obtained.

[0063] The method for evaluating the maximum bleed air volume of the compressor can quickly assess the bleed air volume of the compressor through the established bleed air volume evaluation model. It can evaluate the actual flow state of the airflow caused by the compressor, with low error, short preparation time, and reduced difficulty and cost of compressor bleed air evaluation, thus ensuring the smooth conduct of aero-engine compressor bleed air tests.

[0064] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A method of establishing an evaluation model of a maximum air intake amount of a compressor, characterized by, Includes the following steps: S1. Establish a model formula for evaluating the maximum bleed air volume of the compressor. The model formula is as follows: M=A(f(x1)+b1)(f(x2)+b2)…(f(xi)+bi); In the formula: M is the maximum bleed air volume in the final evaluation, parameter A is the total influence coefficient of the evaluation model, xi is the influence factor of the maximum bleed air volume of the compressor, f(xi) is the underlying function of each influence factor, and bi is the correction coefficient of each influence factor. S2. Obtain sufficient data from the bleed air test specimen interface to evaluate the maximum bleed air volume of the compressor, extract the existing influencing factors and the corresponding maximum bleed air volume M, and divide the data into derivation dataset, correction dataset, and verification dataset. S3. Substitute the data from the derivation dataset obtained in step S2 into the model formula to obtain the underlying function f(xi), correction coefficient bi and parameter A of each influencing factor of the compressor's maximum bleed air volume, and obtain the initial model of the compressor's maximum bleed air volume. S4. Substitute the data from the corrected dataset in step S2 into the obtained initial model to correct the model and obtain the corrected model. S5. Substitute the data in the verification dataset into the correction model and determine whether the calculation error of the verification data is greater than the error requirement value C. If the calculation error is not greater than the error requirement value C, the corrected model obtained in step S4 is the final evaluation model for the maximum bleed air volume of the compressor; if the calculation error of the verification data is greater than the error requirement value C, return to step S3 to obtain a new initial model, then obtain a new corrected model through step S4 and execute step S5, iterating repeatedly until the corrected model meets the error requirement.

2. The method of claim 1, wherein Step S2 includes the following steps: S21. Determine whether the data obtained through the experiment for establishing the evaluation model of the maximum bleed air volume of the compressor is sufficient; if sufficient, proceed to step S3; if insufficient, proceed to step S22 below. S22. Obtain data for establishing an evaluation model of the maximum bleed air volume of the compressor through numerical simulation, and combine this data with some data obtained through experiments into the derivation dataset. The remaining data obtained through experiments are combined into the correction dataset and the verification dataset.

3. The method of claim 1, wherein In step S5, the calculation error of the verification data is defined as follows, assuming the influence factors are the same within the verification dataset: (model calculation flow - test flow) / test flow.

4. The method of claim 1, wherein The derived dataset, the corrected dataset, and the verification dataset must all be distributed across the entire range of data.

5. The method of claim 1, wherein The verification dataset is randomly selected from the data obtained through experiments and is distributed across the entire range of data.

6. The method of claim 1, wherein Factors affecting the maximum bleed air volume of a compressor include the compressor's bleed air inlet pressure, the cross-sectional area of ​​the bleed air inlet, and the airflow temperature.

7. The method of claim 1, wherein The underlying function f(xi) of each influencing factor of the compressor's maximum bleed air volume was obtained by the controlled variable method.

8. A method of evaluating the maximum mass flow of a compressor, characterized in that, The evaluation method includes the following steps: An evaluation model for the maximum bleed air volume of a compressor is established using the method described in any one of claims 1-7. Obtain the parameters of each influencing factor on the maximum bleed air volume of the compressor; By substituting the parameters of each influencing factor of the compressor's maximum bleed air volume into the evaluation model, the compressor's maximum bleed air volume can be obtained.

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