Test method of thrust correction factor in endurance test of civil aviation engine

Abstract

The application discloses a test method for a thrust correction coefficient in a civil aviation engine endurance test, and the test method comprises the following steps: S1, selecting an engine, performing performance evaluation on the engine, and obtaining F a‑i ; S2, modifying the engine and a test bed, and obtaining F b‑i ; S3, calculating K 前‑i ; S4, entering an endurance test; S5, correcting the engine by using K 前‑i , and obtaining F e‑i ; S6, restoring the engine and the test bed to original configurations, and obtaining F f‑i ; S7, calculating K 后‑i ; S8, calculating K 中‑i by using a linear interpolation method. The application solves the problems of long cycle time and high cost of flow field measurement, is beneficial to improving engine research and development efficiency, reducing research and development cost, and shortening a work cycle of type development.

Description

Technical Field

[0001] This invention relates to a test method for the thrust correction coefficient in a sustained test of a civil aircraft engine. Background Technology

[0002] The 150-hour endurance test of an aero-engine is a special demonstration test required by airworthiness regulations. It is also an important milestone in the development process of the model and an unavoidable part of the aero-engine development process in countries around the world. Among the three major OEMs, GE, PW, and RR, each company attaches great importance to the endurance test. Before each aero-engine undergoes endurance test, a thrust calibration test is carried out, and the performance characteristics of the aero-engine are determined according to regulations.

[0003] The results of thrust calibration tests determine the characteristics of an aero-engine across its entire operating range of speed, pressure, temperature, and altitude. Power ratings are based on standard atmospheric conditions (without aircraft bleed air and power extraction). During calibration tests, measurements should only be recorded when the aero-engine is stable at each state. The thrust calibration of the aero-engine is completed through test runs with correction factors. The test results must meet the test requirements in the TCDS (Tracking Control System), and these thrust calibration results must be described in writing in the submitted report.

[0004] During the sustained test runs required by airworthiness regulations for civil aircraft engines, modifications to the test bench and the engine itself are necessary. These modifications include changes to both the engine configuration and the test bench setup, necessitating adjustments and verification to determine thrust. According to CCAR 33.87, sustained test runs require verification of the thrust of a standard aircraft engine. In the early stages of aircraft engine development, when sustained test runs are required, standard aircraft engines and test benches are often unavailable. Therefore, flow field testing methods are typically used for thrust calibration. However, the existing flow field testing methods for thrust calibration not only extend the engine development cycle but are also very expensive, causing numerous inconveniences in aircraft engine development. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the existing method of using flow field testing during thrust calibration test in civil aircraft engine endurance test, which requires a long time cycle and is expensive, and to provide a test method for thrust correction coefficient in civil aircraft engine endurance test.

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

[0007] A test method for thrust correction coefficient in a sustained test of a civil aircraft engine, the test method comprising the following steps:

[0008] S1. Select a stable engine through pre-testing and evaluation, and evaluate the engine's performance according to the thrust correction coefficient corrected by the existing test bench, to obtain the thrust performance data F of the engine under various states in the conventional test configuration. a-i ;

[0009] S2. Modify the engine and the test stand into a long-duration test configuration, and obtain the thrust performance data F of the engine in each state under the long-duration test configuration. b-i ;

[0010] S3, via the F a-i and the F b-i Calculate the thrust correction factor K of the engine in each state before the endurance test. 前-i ;

[0011] S4. The engine enters the sustained test run.

[0012] S5, by using the K 前-i The thrust performance data of the engine under various conditions after the endurance test are corrected to obtain the thrust performance data F of the engine under the endurance test configuration. e-i ;

[0013] S6. Restore the engine and the test stand to their original conventional test configuration, and obtain the thrust performance data F of the engine in each state under the conventional test configuration after the endurance test. f-i ;

[0014] S7, via the F e-i and the F f-i Calculate the thrust correction factor K for each state of the engine after the sustained test run. 后-i ;

[0015] S8, combined with the aforementioned K 前-i and the K 后-i The thrust correction coefficient K of the engine under various states during the sustained test run was calculated using linear interpolation. 中-i .

[0016] Preferably, in step S8:

[0017] K 中-i =K 前-i + (K) 后-i -K 前-i (t) 当前 / t 总)

[0018] Among them, t 当前 t represents the current working time since the start of the long-duration test. 总 This refers to the total working time of the long-term test.

[0019] Preferably, in step S3:

[0020] K 前-i =F a-i / F b-i .

[0021] Preferably, in step S7:

[0022] K 后-i =F f-i / F e-i .

[0023] Preferably, i refers to the engine's operating states such as takeoff, continuous operation, cruise, and idle.

[0024] This solution is designed based on the implementation method of thrust calibration test for sustained testing of civil aero engines. During sustained testing of civil aero engines, in the calibration test process, the state thrust of the engine is calculated and evaluated by combining the existing thrust coefficient (using flow field testing methods) with data transfer methods based on the same engine. This solves the problem in actual R&D work, in the early stages of aero engine model development, where sustained testing is required but standard aero engines and standard test stands are unavailable, and only flow field testing methods can be used for thrust calibration tests. Compared with the flow field testing methods used in the prior art for thrust calibration tests, this invention not only shortens the engine development cycle but also reduces costs, bringing many conveniences to aero engine development.

[0025] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of the present invention.

[0026] The positive and progressive effects of this invention are as follows:

[0027] By adopting the test method in this invention, during the sustained testing process of model development, it is no longer necessary to conduct separate flow field tests or thrust verification of standard engines. This solves the problem of the lack of standard engines in the early stages of model development. Furthermore, by effectively utilizing data, the state thrust correction of the engine can be calculated and evaluated. Flow field tests are no longer required, which solves the problems of long cycle time and high cost of flow field measurement. This is conducive to improving the efficiency of engine development, reducing development costs, and shortening the work cycle of model development. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the test method for the thrust correction coefficient in the endurance test of a civil aircraft engine according to an embodiment of the present invention.

[0029] Figure 2 This is a flowchart illustrating the test method for the thrust correction coefficient in a sustained test of a civil aircraft engine according to an embodiment of the present invention.

[0030] Explanation of reference numerals in the attached figures:

[0031] Takeoff i1

[0032] continuous i2

[0033] Cruise i3

[0034] slow train i4

[0035] Pre-inspection and test drive Step 1

[0036] Equipment Modification and First Calibration Test Step 2

[0037] Get K 前-i Step 3

[0038] Durational testing and test run Step 4

[0039] Second calibration test Step 5

[0040] The engine and test bench were restored to their conventional test configuration. (Step 6)

[0041] Get K 后-i Step 7

[0042] Get K 中-i Step 8

[0043] Current working time t since the start of the endurance test 当前

[0044] Total working time t of the endurance test 总 Detailed Implementation

[0045] The present invention will be described more clearly and completely below by way of embodiments and in conjunction with the accompanying drawings, but the present invention is not limited to the scope of the embodiments described herein.

[0046] This invention provides a test method for the thrust correction coefficient in a sustained test of a civil aircraft engine, such as... Figure 1-2 As shown, the test method includes the following steps:

[0047] S1. Select a stable engine through pre-testing and evaluate its performance using the thrust correction factor corrected by the existing test bench. Obtain the thrust performance data F of the engine under various states in the conventional test configuration. a-i (Where, 'i' refers to the engine's operating states, such as takeoff, continuous, cruise, and idle.) Figure 1 In this context, i1 represents takeoff, i2 represents continuous flight, i3 represents cruise, and i4 represents local flight (i.e., F). a-起飞 F a-连续 F a-巡航 ….F a-慢车 ;

[0048] S2. Modify the engine and test stand into a long-duration test configuration, then conduct the first calibration test on the engine, and obtain the thrust performance data F of the engine in various states under the long-duration test configuration. b-i That is, F b-起飞 F b-连续 F b-巡航 …...F b-慢车 ;

[0049] S3, by passing F a-i and F b-i Substitute into formula K 前-i =F a-i / F b-i The thrust correction factor K of the engine under various conditions before the sustained test run is calculated. 前-i K 前-起飞 K 前-连续 K 前-巡航 ...K 前-慢车 ;

[0050] S4. Conduct a sustained test run of the engine;

[0051] S5. Perform a second calibration test on the engine, using K... 前-i The thrust performance data of the engine under various conditions after the endurance test are corrected to obtain the thrust performance data F of the engine under various conditions in the endurance test configuration. e-i That is, F e-起飞 F e-连续 F e-巡航 …...F e-慢车 ;

[0052] S6. Restore the engine and test stand to their original conventional test configuration, and obtain the thrust performance data F of the engine in each state under the conventional test configuration after the endurance test. f-i That is, F f-起飞 F f-连续 F f-巡航 …...F f-慢车 ;

[0053] S7, By passing F e-i and F f-i Substitute into formula K 后-i =F f-i / F e-i The thrust correction factor K was calculated for each state of the engine after the sustained test run. 后-i K 后-起飞 K 后-连续 K 后-巡航 ...K 后-慢车 ;

[0054] S8, K 前-i and K 后-i Substitute into formula K 中-i =K 前-i + (K) 后-i -K 前-i (t) 当前 / t 总 In the study, the thrust correction coefficient K for each state of the engine during the sustained test run was calculated using linear interpolation. 中-i K 中-起飞 K 中-连续 K 中-巡航 ...K 中-慢车 .

[0055] The experimental method of this invention uses the original engine and test stand as the benchmark for evaluating working parameters during sustained engine testing. These parameters are then linked together through data calculation. This process effectively utilizes initial data and directly completes thrust correction during testing by transferring data between test stands of different configurations based on the same engine. Thrust calibration and correction do not require the use of a standard engine, solving the problem of the lack of a standard engine in the early stages of model development. By effectively utilizing initial data, the parameter evaluation process does not require re-arranging flow field tests, solving the problems of long cycle time and high cost in existing flow field measurements. During sustained engine testing in model development, separate flow field tests or thrust verification of a standard engine are no longer necessary, solving the problem of the lack of a standard engine in the early stages of model development. Furthermore, by effectively utilizing data to calculate and evaluate the engine's state-of-the-art thrust correction, and eliminating the need for flow field tests, the problem of long cycle time and high cost in flow field measurements is solved. This improves engine development efficiency, reduces development costs, and shortens the model development cycle.

[0056] 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 test method for the thrust correction coefficient in a sustained test of a civil aircraft engine, characterized in that, The experimental method includes the following steps: S1. Select a stable engine through pre-testing and evaluation, and evaluate the engine's performance according to the thrust correction coefficient corrected by the existing test bench, to obtain the thrust performance data F of the engine under various states in the conventional test configuration. a-i ; S2. Modify the engine and the test stand into a long-duration test configuration, and obtain the thrust performance data F of the engine in each state under the long-duration test configuration. b-i ; S3, via the F a-i and the F b-i Calculate the thrust correction factor K of the engine in each state before the endurance test. 前-i ; S4. The engine enters the sustained test run. S5, by using the K 前-i The thrust performance data of the engine under various conditions after the endurance test are corrected to obtain the thrust performance data F of the engine under the endurance test configuration. e-i ; S6. Restore the engine and the test stand to their original conventional test configuration, and obtain the thrust performance data F of the engine in each state under the conventional test configuration after the endurance test. f-i ; S7, via the F e-i and the F f-i Calculate the thrust correction factor K for each state of the engine after the sustained test run. 后-i ; S8, combined with the aforementioned K 前-i and the K 后-i The thrust correction coefficient K of the engine under various states during the sustained test run was calculated using linear interpolation. 中-i ; The number 'i' refers to the engine's takeoff, continuous, cruise, and idle operating states, respectively.

2. The test method for thrust correction coefficient in the endurance test of a civil aircraft engine as described in claim 1, characterized in that, In step S8: K 中-i =K 前-i +(K 后-i -K 前-i )(t 当前 / t 总 ) Among them, t 当前 t represents the current working time since the start of the long-duration test. 总 This refers to the total working time of the long-term test.

3. The test method for thrust correction coefficient in the endurance test of a civil aircraft engine as described in claim 2, characterized in that, In step S3: K 前-i =F a-i / F b-i 。 4. The test method for thrust correction coefficient in the endurance test of a civil aircraft engine as described in claim 3, characterized in that, In step S7: K 后-i =F f-i / F e-i 。

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