Thrust measurement device and method for improving engine thrust measurement precision and stability

Abstract

The invention discloses a thrust measuring device and a thrust measuring method for improving the thrust measuring precision and stability of an engine. The measuring device comprises a fixed frame, a movable frame, a rear spring piece, a front spring piece, a left thrust sensor, a left measuring cable, a right thrust sensor, a right measuring cable, a sensor power supply, a data collector and a computer. The movable frame is hung on the fixed frame through the two front spring pieces and the two rear spring pieces, a left thrust sensor and a right thrust sensor are fixedly installed on the fixed frame, and the left thrust sensor and the right thrust sensor are symmetrically arranged about the axis of the aero-engine to be tested. When the thrust is measured, the measuring method that double thrust sensors are configured with double-channel data acquisition and superposition is adopted, the stability of thrust measurement is improved, the influence of interference is reduced, the fluctuation of the thrust is reduced, and the measuring precision is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of engine test and measurement technology, and particularly relates to a thrust measurement device and method for improving the accuracy and stability of engine thrust measurement. BACKGROUND

[0002] Thrust is the reaction force generated by the high-speed jet flow of an aero gas turbine engine acting on the atmospheric environment, which is used to push the aircraft to fly. The thrust is measured by a thrust measurement system during the test run of an aero-engine test bed. The thrust measurement system is composed of a thrust sensor and a data acquisition system. At present, based on the existing force sensor technology, the output electric signal of the thrust sensor produced at home and abroad is relatively small, generally about 20mv. Therefore, the engine thrust measurement is easily affected by interference. The main reason for the signal interference of the test bed is that multiple different high-power power supplies are used during the test run. With the change of the engine working state, the power of various power supplies is constantly changing. The electromagnetic interference generated by these high-power power supplies is superimposed on the test bed thrust measurement circuit, resulting in a large swing and jump of the measured thrust during the engine test run, which usually reaches about 100-200kg, seriously affecting the accuracy of the engine thrust measurement.

[0003] Specifically, the engine thrust measurement of the test bench currently generally adopts a measurement method of single thrust sensor with multiple channels of the data acquisition system, which is simple to measure, easy to maintain and calibrate, and can be completed at one time, but has certain limitations, i.e., there is no problem in static calibration, since the engine is not started, various high-power power supplies are not in operation, the interference is small, and the calibration accuracy and accuracy basically meet the requirements, but when the engine test is completed, various interferences will be generated and superimposed into the thrust measurement, so that the measured thrust has large fluctuation and swing, which seriously affects the accuracy of the thrust measurement, and the reasons are as follows: the output voltage of basically all thrust sensors is about 20mv at full scale, the measurement channel of the data acquisition system generally adopts ±5V sampling, so the signal needs to be amplified, and the calculation is based on the maximum sampling voltage of A / D +5V (the -5V is mainly used when the zero position is negative), at this time, if the measured engine thrust is 15 tons, i.e., 15000kg, the corresponding relationship between the signal 5V and the 15000kg thrust is 5V÷15000kg=0.00033V / kg, which is equivalent to 0.33mv corresponding to 1kg thrust, and the electromagnetic interference generated by the high-power power supply on site, even if the electromagnetic shielding is good, is usually between dozens of mv, which leads to large swing and fluctuation of the measured thrust during the engine test, which usually reaches about 100-200kg, seriously affecting the accuracy of the engine thrust measurement, and the on-site processing adopts the method of average filtering to reduce the fluctuation, which basically meets the use, but sacrifices the dynamic response characteristics of the measured thrust, and cannot meet the rapid measurement of the transient state thrust, and the existing measurement scheme principle diagram is shown in Figure 1 . Figure 1 In the measurement scheme principle diagram, the sensor is installed in the middle of the fixed frame and the movable frame, the base is installed on the fixed frame, the other end is in contact with the movable frame through the jacking rod, the threaded length of the jacking rod is adjustable, a certain pre-tightening force is applied in use to ensure good contact and effective force transmission, and the pre-tightening force is calibrated as the zero position during calibration, which is equivalent to skinning. SUMMARY

[0004] The present application aims to provide a thrust measurement device and measurement method for improving the measurement accuracy and stability of the engine thrust, which can meet the dynamic and static measurement requirements of the aero-engine thrust test, reduce the measurement error, and improve the measurement accuracy and stability.

[0005] To achieve the above-mentioned purpose, the present application adopts the following technical scheme: A thrust measurement device for improving the measurement accuracy and stability of the engine thrust, comprising: Right and left thrust sensors, the right and left thrust sensors are the same in specification and are symmetrically arranged about the aero-engine axis; The data acquisition device includes at least two independent acquisition channels, one of which is connected to the right thrust sensor and the other is connected to the left thrust sensor; A fixed frame is fixed on a horizontal plane, and a right thrust sensor and a left thrust sensor are mounted on the fixed frame. The moving frame is suspended below the fixed frame by two front spring plates and two rear spring plates. The moving frame is connected to the aero-engine at the bottom. The two front spring plates and two rear spring plates are of the same specification and are distributed at the four vertices of a rectangle. The moving frame is equipped with a right actuating block and a left actuating block that are symmetrical about the aero-engine. The right actuating block cooperates with the right thrust sensor through a push rod, and the left actuating block cooperates with the left thrust sensor through a push rod.

[0006] Furthermore, thrust measurement devices that improve the accuracy and stability of engine thrust measurement also include: The sensor power supply is connected to the right thrust sensor via the right measuring cable and to the left thrust sensor via the left measuring cable. A computer connected to a data acquisition unit.

[0007] As one option, both the fixed frame and the moving frame are rectangular frames.

[0008] A thrust measurement method for improving the accuracy and stability of engine thrust measurement, employing the aforementioned thrust measurement device, and comprising: Step 1: Determine the range of the thrust sensor. Select two identical right and left thrust sensors, using half of the total thrust of the aero-engine to be measured as the range. Step 2: Check that there are no other connections between the moving frame and the fixed frame besides the two front spring plates and the two rear spring plates, and that there is no interference on the moving path of the moving frame. Step 3: Install the aircraft engine to be tested under the moving frame, with the axis of the aircraft engine parallel to the horizontal direction; Step 4: Start the aircraft engine under test, and trigger the right thrust sensor and left thrust sensor through the right and left actuator blocks to measure the thrust values ​​under static and dynamic conditions respectively.

[0009] As one approach, in step four, when measuring thrust values ​​under static and dynamic conditions, the data acquisition unit uses a 10V voltage for sampling.

[0010] This invention proposes a measurement method that combines dual-thrust sensor configuration with dual-channel data acquisition and superposition. It modifies the existing single-thrust measurement method by measuring and superimposing dual thrusts separately. Compared with single-thrust measurement, this invention has the following advantages: (1) The present invention improves the stability of thrust measurement, reduces the influence of interference, and reduces thrust fluctuation; (2) From the perspective of A / D quantization, obtaining the superposition of two 10V voltage signals by A / D conversion improves the measurement accuracy and reduces the difficulty of electromagnetic shielding. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of an existing engine thrust measurement device; Figure 2 This is a schematic diagram of the improved engine thrust measuring device of the present invention; In the diagram: 1—Right thrust sensor; 2—Fixed frame; 3—Moving frame; 4—Rear spring plate; 5—Right measuring cable; 6—Sensor power supply; 7—Left measuring cable; 8—Computer; 9—Data acquisition unit; 10—Aircraft engine; 11—Left thrust sensor; 12—Front spring plate. Detailed Implementation

[0012] The present invention will be further described below with reference to specific embodiments, but it should not be construed as limiting the scope of the subject matter of the present invention to the following embodiments. All modifications, substitutions and alterations made based on ordinary technical knowledge and common practices in the art without departing from the above-described technical concept of the present invention are included within the scope of the present invention.

[0013] To improve the accuracy and stability of engine thrust measurement, this invention proposes a dual-thrust superposition measurement method using dual thrust sensors paired with a data acquisition system employing dual-channel 0-10V sampling. This method can improve the accuracy and stability of thrust measurement by more than two times. The specific method is as follows: A dual-sensor + data acquisition system with dual channels is employed, meaning one sensor is paired with one channel. The sensors are mounted on the left and right sides of the test bench, respectively. Each sensor handles half of the engine's thrust, thus halving the sensor's range. For example, a 15000kg range can be reduced to 7500kg. Using a 7500kg range sensor, the full-scale output remains 20mV. With the data acquisition system configured, the signal is amplified to 10V. The other channel follows the same method, effectively doubling the correlation between thrust and the acquired voltage: 10V ÷ 7500kg + 10V ÷ 7500kg = 0.0027V / kg. That is, 2.7 mv / kg, which is 8.18 times the original 2.7 / 0.33. After the measurement method was improved, the thrust fluctuation or oscillation changed from the original 100-200 kg to about 15-25 kg. After using about 5 average filters, the number of oscillations is within 10 kg, and the dynamic response of the thrust is basically not reduced, which fully meets the thrust measurement requirements of the carrier-based aircraft in the transition state.

[0014] like Figure 2As shown, the thrust measurement device for improving the accuracy and stability of engine thrust measurement mainly consists of a fixed frame 2, a moving frame 3, a rear spring plate 4, a front spring plate 11, a left thrust sensor 10, a left measuring cable 7, a right thrust sensor 1, a right measuring cable 5, a sensor power supply 6, a data acquisition unit 9, and a computer 8. Both the fixed frame 2 and the moving frame 3 are rigid rectangular frames (they cannot easily deform, otherwise deformation will affect the accuracy of thrust measurement). The fixed frame 2 and the moving frame 3 can only be connected by four spring plates (two front spring plates 12 and two rear spring plates 4). The spring plates are sheet-like... The spring and the moving frame 3 are in an elastic state (i.e., within the elastic deformation range of the spring sheet), and no tension or interference is allowed. The aircraft engine 10 to be tested is mounted on the moving frame 3. The moving frame 3 is equipped with a left actuating block and a right actuating block for thrust transmission. A push rod (i.e., a support rod with adjustable length) is mounted on the left actuating block. Similarly, a push rod is mounted on the right actuating block. The length of the push rod is adjustable, and the preload force can be applied to the left thrust sensor 10 and the right thrust sensor 1 and the gap can be eliminated by adjusting the length, while ensuring that the left thrust sensor 10 and the right thrust sensor 1 are easy to disassemble. When the aero-engine 10 is working, the high-speed exhaust gas acts on the atmosphere, and the atmospheric reaction force, i.e., the thrust of the aero-engine 10, propels the aero-engine 10 forward. At the same time, the aero-engine 10 drives the actuator 3 forward. As the actuator 3 moves forward, the left and right actuator blocks on the actuator 3 press the left thrust sensor 10 and the right thrust sensor 1 through the push rod, respectively. The left thrust sensor 10 and the right thrust sensor 1 convert the magnitude of the thrust into an electrical signal, which is transmitted to the data acquisition unit 9 through the left measuring cable 7 and the right measuring cable 5. The data acquisition unit 9 amplifies the electrical signals output by the left thrust sensor 10 and the right thrust sensor 1, converts them into digital signals by A / D conversion, and transmits them to the computer 8. The digital signal received by the computer 8 is the obtained data. The computer 8 calculates the corresponding thrust of the obtained data, obtains the magnitude of the left and right thrust, and displays and stores the superimposed left and right thrust, thus completing the measurement of engine thrust.

[0015] The thrust measurement device for improving the accuracy and stability of engine thrust measurement in this invention uses the FC-T 100KN thrust sensor from Institute 304, the data acquisition unit 9 is the EP-L1033 manufactured by Chengdu Enfit Co., Ltd., and the sensor power supply 6 is a 24V DC power supply from the domestic Chaoyang Power 4NIC.

[0016] Contents not described in detail in this specification are prior art known to those skilled in the art. Although illustrative specific embodiments of the invention have been described above to facilitate understanding by those skilled in the art, it should be understood that the invention is not limited to the scope of the specific embodiments. Various modifications are readily apparent to those skilled in the art as long as they fall within the spirit and scope of the invention as defined and determined by the appended claims, and all inventions utilizing the concept of this invention are protected.

Claims

1. A thrust measuring device for improving the accuracy and stability of engine thrust measurement, characterized by, It comprises: Right thrust sensor (1) and left thrust sensor (11), the right thrust sensor (1) and left thrust sensor (11) are the same specification, and are symmetrically arranged about the axis of aero-engine (10); Data collector (9), the data collector (9) comprises at least two independent acquisition channels, one of which is connected with the right thrust sensor (1), and the other is connected with the left thrust sensor (11); Fixed frame (2), the right thrust sensor (1) and the left thrust sensor (11) are installed on the fixed frame (2); Movable frame (3), the movable frame (3) is suspended below the fixed frame (2) by two front spring sheets (12) and two rear spring sheets (4), the movable frame (3) is connected with the aero-engine (10) below, the two front spring sheets (12) and the two rear spring sheets (4) are completely the same specification, and are distributed at the four vertices of the rectangle, the movable frame (3) is provided with right and left actuator blocks symmetrically about the aero-engine (10), wherein the right actuator block is matched with the right thrust sensor (1) through a top rod, and the left actuator block is matched with the left thrust sensor (11) through a top rod.

2. The thrust measuring device of claim 1, wherein, It also comprises: Sensor power supply (6), the sensor power supply (6) is connected with the right thrust sensor (1) through the right measuring cable (5), and is connected with the left thrust sensor (11) through the left measuring cable (7); Computer (8), the computer (8) is connected with the data collector (9).

3. The thrust measuring device of claim 1, wherein: The fixed frame (2) and the movable frame (3) are both rectangular frames.

4. A thrust measurement method for improving the accuracy and stability of engine thrust measurement, characterized by, The thrust measuring device of claim 1 or 2 or 3 is adopted, and comprises: Step one, determine the range of thrust sensor, take half of the total thrust of the aero-engine (10) to be measured as the range, select two right thrust sensors (1) and left thrust sensors (11) which are completely the same specification; Step two, check that there is no other connection between the movable frame (3) and the fixed frame (2) except the two front spring sheets (12) and the two rear spring sheets (4), and there is no interference in the moving path of the movable frame (3); Step three, install the aero-engine (10) to be measured below the movable frame (3), and the axis of the aero-engine (10) is parallel to the horizontal direction; Step four, start the aero-engine (10) to be measured, trigger the right thrust sensor (1) and the left thrust sensor (11) through the right actuator block and the left actuator block, and measure the thrust value under static and dynamic conditions respectively.

5. The thrust measurement method of claim 4, wherein: In step four, when measuring the thrust value under static and dynamic conditions, the data collector (9) uses 10V voltage for sampling.

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