Wind tunnel performance test and analysis method for a pull-in contra-rotating propeller fan

Abstract

This application discloses a wind tunnel performance test and analysis method for a pull-in counter-rotating propeller fan, comprising the following steps: S1, conducting a wind tunnel test verification in a bladeless state, where the test state is consistent with the test requirements for a test piece with blades, to obtain the resistance of the straightening propeller cap for use in correcting the blade test parameters; S2, conducting a wind tunnel test verification in a bladed state to obtain the tension and torque of the front and rear blades, and correcting the tension and torque of the front and rear blades by the resistance of the straightening propeller cap to obtain the actual blade parameters. This application can obtain the actual performance parameters of the wind tunnel test of the corresponding type of counter-rotating propeller fan test piece through the above method, thereby improving the accuracy of the wind tunnel performance test and thus obtaining the actual performance parameters of this type of counter-rotating propeller fan.

Description

Technical Field

[0001] The present application relates to the field of engine testing technology, and in particular, to a wind tunnel performance test and analysis method for a pull-in counter-rotating propeller fan. Background Art

[0002] Propfan engines combine the high Mach numbers of turbofans with the high propulsion efficiency of turboprops. In the global context of energy conservation and emissions reduction, they represent a promising green power source for the future. Major international engine manufacturers view them as a key development direction for advanced engines. In the 1980s, Hamilton Aircraft proposed counter-rotating propfan technology and completed full-machine verification and flight testing. GE developed unducted fan technology, completing ground-based full-machine verification and flight demonstrations. In the 1990s, Ukraine completed the development of a counter-rotating propfan engine model, which entered service on the An-70 transport aircraft. In the 21st century, Safran developed a propulsion open rotor engine as part of the European Clean Sky program and completed full-machine verification on a ground-based open-air test bench in 2017.

[0003] Based on their installation location, propfan engines are divided into two categories: the first is a pull-in counter-rotating propfan engine, with the blades at the front of the engine, such as the Ukrainian D27; the second is a push-in counter-rotating propfan engine, with the blades at the rear of the engine, such as GE's GE36. There are generally two approaches to verifying the aerodynamic performance of counter-rotating propfans: First, flight testing with the engine equipped with a full-scale propfan can obtain realistic aerodynamic performance. However, aerial testing presents safety issues and is very expensive, and it is difficult to arrange tension and torque measurement devices on the engine. Therefore, such tests are generally only conducted during the finalization phase; second, using scaled-down test pieces, based on similarity theory, and using a wind tunnel to simulate high-altitude inflow conditions, relevant performance verification tests and aerodynamic mechanism tests are conducted.

[0004] At present, propeller or propeller fan component test pieces at home and abroad usually use rotating balances to measure tension and torque. Due to the structural factors of the test pieces, different part structures will cause deviations in the measurement data, so the existing technology cannot obtain the actual performance parameters of the propeller fan. Summary of the Invention

[0005] In response to the above technical problems, the present application provides a wind tunnel performance test and analysis method for a pull-in counter-rotating propeller fan to solve the technical problem that in existing counter-rotating propeller fan tests, due to the structural factors of the test piece, different parts will cause deviations in the measurement data and the actual performance parameters of the propeller fan cannot be obtained.

[0006] The technical solutions adopted in this application are as follows:

[0007] A wind tunnel performance test and analysis method for a pull-in contra-rotating propeller fan comprises the following steps:

[0008] S1. Conduct wind tunnel tests without blades. The test conditions are consistent with the test requirements for the test piece with blades to obtain the resistance of the fairing cap for use in correcting the blade test parameters.

[0009] S2. Conduct wind tunnel tests with the blades attached to obtain the tension and torque of the front and rear blades. Correct the tension and torque of the front and rear blades using the resistance of the fairing cap to obtain the actual parameters of the blades.

[0010] Furthermore, step S1 specifically includes the steps of:

[0011] S11. Remove the front and rear blades of the test piece and replace them with unprocessed front and rear independent petioles made of the same material. Ensure the flow path is continuous after installation.

[0012] S12. Place the test piece with the front and rear independent blade petioles replaced in a wind tunnel for testing. The test conditions are consistent with those for the test piece with blades.

[0013] S13, obtaining aerodynamic forces detected by the front row propeller rotating balance and the rear row propeller rotating balance under different incoming flow Mach numbers and measuring the static pressure in the hub cavity;

[0014] S14. For the front row propeller, set D sp is the resistance of the spinner cap, P sb is the static pressure in the hub cavity, then the force applied to the inner wall of the front propeller hub is D pf =P sb *A sp , where A sp is the effective area, and the front row propeller rotation balance measurement value is T rsbf , then the resistance of the fairing cap is calculated as:

[0015] D sp =T rsbf +D pf ;

[0016] S15. For the rear row propeller, since the rear row propeller hub is connected front to back, the rear row propeller rotation balance measurement value T rsbr Too small to be ignored.

[0017] Furthermore, step S2 specifically includes the steps of:

[0018] S21. Conduct a wind tunnel performance test on the propeller blade test piece, using a front-row propeller rotating balance and a rear-row propeller rotating balance to measure the blade's combined tension and torque under different conditions.

[0019] S22. For the front row propeller, calculate the pull force Tb on the front row propeller blades. f for:

[0020] Tb f＝ T rsbf +D sp +D pf

[0021] Among them, T rsbf The measurement value of the front row paddle rotation balance 4, D sp is the propeller cap resistance, D pf is the force applied to the inner wall of the front propeller hub and D pf =P sb* A sp , P sb is the static pressure in the hub cavity, A sp is the effective area;

[0022] S23. For the rear row propeller, the value measured by the rear row propeller rotation balance is the blade tension, so the rear row propeller blade tension Tb r for:

[0023] Tb r =T rsbr .

[0024] Furthermore, the front row propeller rotary balance and the rear row propeller rotary balance adopt six-component spoke rotary balance.

[0025] Compared with the existing technology, this application has the following beneficial effects:

[0026] The present application provides a wind tunnel performance test and analysis method for a pull-in counter-rotating propeller fan, comprising the steps of: S1, conducting a wind tunnel test verification in a bladeless state, wherein the test state is consistent with the test requirements of a test piece with blades, so as to obtain the resistance of a straightening propeller cap for use in correcting the blade test parameters; S2, conducting a wind tunnel test verification in a blade-carrying state, obtaining the tension and torque of the front and rear blades, and obtaining the actual blade parameters after correcting the tension and torque of the front and rear blades by the resistance of the straightening propeller cap.

[0027] This application conducts a force analysis based on the structural characteristics of the test piece, and proposes that the torque value measured by the rotating balance is the actual torque value, the rear propeller tension is the actual tension value, and the front propeller is the comprehensive tension, including the blade tension, the resistance of the straightening propeller cap, and the force in the hub cavity. The resistance of the straightening propeller cap is measured in different states through a bladeless test piece, and its value is obtained by the tension of the rotating balance of the front propeller and the force of the inner wall of the front propeller hub in this state, which is used to correct the aerodynamic parameters of the test piece with blades. Then, the comprehensive tension of the front propeller is measured through the test piece with blades, and the actual tension of the front propeller is obtained according to the comprehensive tension of the front propeller, the resistance of the straightening propeller cap and the force in the hub cavity. The above method can obtain the actual performance parameters of the wind tunnel test of this type of counter-rotating propeller fan test piece, improve the accuracy of the wind tunnel performance test, and thus obtain the actual performance parameters of this type of counter-rotating propeller fan.

[0028] In addition to the above-described purposes, features and advantages, the present application has other purposes, features and advantages. The present application will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of this application. The exemplary embodiments and descriptions of this application are intended to explain this application and do not constitute an improper limitation on this application. In the accompanying drawings:

[0030] Figure 1 A schematic flow chart of a wind tunnel performance test and analysis method for a pull-in contra-rotating propeller fan provided in a preferred embodiment of the present application;

[0031] Figure 2 This is a schematic diagram of the bladeless test principle of a counter-rotating propeller fan according to a preferred embodiment of the present application;

[0032] Figure 3 This is a schematic diagram of the blade test principle of a counter-rotating propeller fan according to a preferred embodiment of the present application;

[0033] Figure 4 This is a schematic diagram of the forces acting on each component during the force measurement test of the fairing cap;

[0034] Figure 5 This is the force diagram of each component of the counter-rotating propeller fan with blade test piece performance test.

[0035] In the figure: 1. Fairing propeller cap; 2. Front row of blades; 3. Rear row of blades; 4. Rotating balance for front row propellers; 5. Rotating balance for rear row propellers; 6. Static pressure measuring device in the hub cavity; 7. Front row independent blade petiole; 8. Rear row independent blade petiole. DETAILED DESCRIPTION

[0036] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this 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.

[0037] Reference Figure 1 The preferred embodiment of the present application provides a wind tunnel performance test and analysis method for a pull-in contra-rotating propeller fan, comprising the following steps:

[0038] S1. Conduct wind tunnel tests without blades. The test conditions are consistent with the test requirements for the bladed test piece to obtain the resistance of the fairing cap 1 for use in correcting the blade test parameters.

[0039] S2. Conduct a wind tunnel test with the blades attached to obtain the tension and torque of the front blades 2 and the rear blades 3. Correct the tension and torque of the front blades 2 and the rear blades 3 using the resistance of the fairing cap 1 to obtain the actual parameters of the blades.

[0040] The method of this embodiment includes the steps of: S1, performing a wind tunnel test verification in a state without blades, the test state is consistent with the test requirements of the test piece with blades, so as to obtain the resistance of the straightening propeller cap, which is used for correcting the blade test parameters; S2, performing a wind tunnel test verification in a state with blades, obtaining the tension and torque of the front and rear blades, and obtaining the actual blade parameters after correcting the tension and torque of the front and rear blades by the resistance of the straightening propeller cap.

[0041] This embodiment performs a force analysis based on the structural characteristics of the test piece, and proposes that the torque value measured by the rotating balance is the actual torque value, the rear propeller tension is the actual tension value, and the front propeller is the comprehensive tension, including the blade tension, the resistance of the straightening propeller cap 1, and the force in the hub cavity. The resistance of the straightening propeller cap 1 under different states is measured by the test piece without blades, and its value is obtained by the tension of the rotating balance of the front propeller and the force of the inner wall of the front propeller hub in this state, which is used to correct the aerodynamic parameters of the test piece with blades. Then, the comprehensive tension of the front propeller is measured by the test piece with blades, and the actual tension of the front propeller is obtained according to the comprehensive tension of the front propeller, the resistance of the straightening propeller cap 1 and the force in the hub cavity. The above method can be used to obtain the actual performance parameters of the wind tunnel test of this type of counter-rotating propeller fan test piece, thereby improving the accuracy of the wind tunnel performance test, thereby obtaining the actual performance parameters of this type of counter-rotating propeller fan.

[0042] Specifically, the step S1 includes the following steps:

[0043] S11. Remove the front row blades 2 and rear row blades 3 of the test piece and replace them with the front row independent petioles 7 and rear row independent petioles 8 made of the same material but unprocessed. Ensure the flow path is continuous after installation (see Figure 2 );

[0044] S12. Place the test piece with the front row independent blade petioles 7 and the rear row independent blade petioles 8 in a wind tunnel for testing. The test conditions are consistent with the requirements for the test piece with blades.

[0045] S13, obtaining the aerodynamic forces detected by the front row propeller rotating balance 4 and the rear row propeller rotating balance 5 under different incoming flow Mach numbers and measuring the static pressure in the hub cavity;

[0046] S14, such as Figure 4 The force analysis shown in the figure shows that for the front blade 2, let D sp is the resistance of the spinner cap 1, P sb is the static pressure in the hub cavity, then the force applied to the inner wall of the front propeller hub is D pf =P sb *A sp , where A sp is the effective area, and the measurement value of the front row propeller rotating balance 4 is T rsbf , then the resistance of the fairing cap 1 is calculated as:

[0047] D sp =T rsbf +D pf ;

[0048] S15. For the rear row propeller, since the rear row propeller hub is connected front to back, the rear row propeller rotating balance 5 measures the value T rsbr Too small to be ignored.

[0049] In this embodiment, the resistance of the straightening propeller cap 1 is obtained by the force of the inner wall surface of the front propeller hub and the measurement value of the front row propeller rotating balance 4, which is used for the correction of the blade test parameters. The force of the inner wall surface of the front row propeller hub is obtained by multiplying the static pressure in the hub cavity and the effective area of ​​the inner wall surface of the front row propeller hub, and the static pressure in the hub cavity can be measured by the hub cavity static pressure measuring device 6. The commonly used hub cavity static pressure measuring device 6 includes strain gauges, pressure sensors, etc.

[0050] Specifically, step S2 includes the following steps:

[0051] S21. Conduct a wind tunnel performance test on the blade test piece, and use the front row propeller rotating balance 4 and the rear row propeller rotating balance 5 to measure the blade comprehensive tension and torque under different conditions (see Figure 3 );

[0052] S22, by Figure 5 From the force analysis shown, it can be seen that for the front row of propellers, the pull force on the front row of blades is calculated as:

[0053] Tb f＝ T rsbf +D sp +D pf

[0054] Among them, T rsbf The measurement value of the front row paddle rotation balance 4, D sp D is the resistance of the spinner cap 1, pf is the force applied to the inner wall of the front propeller hub and D pf =P sb* A sp , P sb is the static pressure in the hub cavity, A sp is the effective area;

[0055] S23. For the rear row propeller, the value measured by the rear row propeller rotation balance 5 is the blade tension, and the tension on the rear row propeller blade is:

[0056] Tb r =T rsbr .

[0057] Due to structural reasons, the straightening propeller cap 1 rotates together with the front row of blades 2, and the resistance generated will also be included in the test results, affecting the test results. In order to ensure the accuracy of the test results, this embodiment is based on actual force analysis. The actual pull on the front row of blades is calculated through the measurement value of the front row propeller rotating balance 4, the force of the inner wall of the front row propeller hub and the resistance of the straightening propeller cap 1, and the measurement value of the propeller rotating balance 5 is used as the actual pull on the rear row of blades, thereby ensuring the accuracy of the test data.

[0058] Based on the above test and analysis methods, the actual thrust and torque of the front and rear rows of propellers of the counter-rotating propeller fan can be obtained. Knowing the wind tunnel test conditions, rotational speed and blade geometric parameters, the propeller fan test performance parameters such as advance ratio, propulsion efficiency, power coefficient and thrust coefficient can be calculated to obtain the actual performance parameters of the counter-rotating propeller fan in the wind tunnel test.

[0059] Specifically, the front row paddle rotary balance 4 and the rear row paddle rotary balance 5 are six-component spoke rotary balances.

[0060] Obviously, those skilled in the art may make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if such changes and modifications of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such changes and modifications.

Claims

1. A wind tunnel performance test and analysis method for a pull-in contra-rotating propeller fan, characterized in that: Including steps: S1. Performing wind tunnel tests without blades, where the test conditions are consistent with the test requirements for the bladed test piece, to obtain the resistance of the fairing cap (1) for use in correcting the blade test parameters; S2. Performing wind tunnel tests with the blades attached to obtain the tension and torque of the front row blades (2) and the rear row blades (3). Correcting the tension and torque of the front row blades (2) and the rear row blades (3) by the resistance of the straightening propeller cap (1) to obtain the actual parameters of the blades. Step S1 specifically includes the following steps: S11. Remove the front row blades (2) and the rear row blades (3) of the test piece and replace them with the front row independent petioles (7) and the rear row independent petioles (8) made of the same material but unprocessed. Ensure the flow path is continuous after installation. S12, placing the test piece with the front row independent petiole (7) and the rear row independent petiole (8) in a wind tunnel for testing, and the test conditions are consistent with the requirements for the test piece with blades; S13, obtaining aerodynamic forces detected by the front row propeller rotating balance (4) and the rear row propeller rotating balance (5) under different incoming flow Mach number states and measuring the static pressure in the propeller hub cavity; S14. For the front row propeller, set D sp is the resistance of the fairing cap (1), P sb is the static pressure in the hub cavity, then the force applied to the inner wall of the front propeller hub is D pf =P sb *A sp , where A sp is the effective area, and the measurement value of the front propeller rotation balance (4) is T rsbf , then the resistance of the fairing cap (1) is calculated as: D sp =T rsbf +D pf ; For the rear row propeller, since the rear row propeller hub is connected front to back, the rear row propeller rotation balance (5) measures the value T rsbr Too small to be ignored; Step S2 specifically includes the following steps: S21, conducting a wind tunnel performance test on the propeller blade test piece, and using a front row propeller rotating balance (4) and a rear row propeller rotating balance (5) to respectively measure the comprehensive tension and torque of the propeller blade under different states; S22. For the front row propeller, calculate the pull force Tb on the front row propeller blades. f for: Tb f＝ T rsbf +D sp +D pf Among them, T rsbf is the measurement value of the front row propeller rotation balance (4), D sp D is the resistance of the fairing cap (1), pf is the force applied to the inner wall of the front propeller hub and D pf =P sb* A sp , P sb is the static pressure in the hub cavity, A sp is the effective area; S23. For the rear row propeller, the value measured by the rear row propeller rotation balance (5) is the blade tension, so the tension Tb on the rear row propeller blade is r for: Tb r =T rsbr 。 2. The wind tunnel performance test and analysis method for a pull-in contra-rotating propeller fan according to claim 1 is characterized in that: The front-row paddle rotary balance (4) and the rear-row paddle rotary balance (5) adopt six-component spoke rotary balances.

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