Semiconductor box balance and test method applied to engine performance test

Abstract

The application belongs to the technical field of engines, and discloses a semiconductor box-type balance applied to engine performance testing and a test method thereof. The semiconductor box-type balance is a three-layer stacked structure; the upper layer is a floating frame provided with a model support plate interface; the lower layer is a fixed frame provided with a support mechanism interface; and the middle layer is a measurement layer including Z-shaped elastic connecting rods located at four corners and a center. Flexible hinges and measurement beams are arranged on the Z-shaped elastic connecting rods, and semiconductor strain gauges and wiring terminals are pasted on the measurement beams. The semiconductor box-type balance effectively reduces the interference between components of the balance through balance structure design, and improves the rigidity of the balance. The temperature self-compensation semiconductor strain gauge improves the force measurement accuracy, and the temperature self-compensation technology reduces or even eliminates the temperature effect of the balance, improves the engine thrust and drag performance measurement accuracy and stability. The test method is suitable for engine static thrust testing, engine drag performance testing and engine thrust-drag ratio performance testing.

Description

Technical Field

[0001] This invention belongs to the field of engine technology, specifically relating to a semiconductor box balance used for engine performance testing and its testing method. Background Technology

[0002] When conducting engine thrust performance tests in a free-jet wind tunnel, the balance is required to have a fast response speed, high rigidity, and strong ability to withstand normal loads due to limitations such as the large mass of the test model, the large aerodynamic load, and the large aerodynamic load impact during test start-up and shutdown. At the same time, because the model includes an air intake, combustion chamber, and tail nozzle, the balance cannot be configured with an internal tail support layout and generally adopts an external belly support box structure.

[0003] The main requirements for wind tunnel balances in engine thrust tests are: First, high rigidity is required. Engine thrust tests require the presence of bleed air devices, which are connected to the intake pipe. During the test, additional forces and torques are generated. In addition, the balance must withstand the aerodynamic impact forces during wind tunnel startup or shutdown. Therefore, the balance used for thrust tests must have higher rigidity. Second, the load components are mismatched. The balance needs to support the engine and nozzle simulation device, resulting in relatively large normal force and pitching moment loads. Third, high measurement accuracy is required. The forces and torques acting on the engine need to be measured directly under both cold and hot conditions. Fourth, the balance must withstand the negative pressure and temperature environment of the wind tunnel high-pressure chamber.

[0004] Currently, there is an urgent need to develop a semiconductor box balance and its testing method for engine performance testing. Summary of the Invention

[0005] One technical problem to be solved by the present invention is to provide a semiconductor box balance for engine performance testing. Another technical problem to be solved by the present invention is to provide a test method for a semiconductor box balance for engine performance testing, and to develop a test technology for accurately measuring engine thrust performance in a wind tunnel environment.

[0006] The semiconductor box balance of the present invention, applied to engine performance testing, is characterized in that the semiconductor box balance is made of F141 and has a three-layer stacked structure; the upper layer is a floating frame with a model support plate interface; the lower layer is a fixed frame with a support mechanism interface; the middle layer is a measuring layer, including Z-shaped elastic links located at the four corners and the center; the lower feet of the Z-shaped elastic links at the four corners are fixed to the upper surface of the fixed frame, and the upper feet of the Z-shaped elastic links are fixed to the lower surface of the floating frame by flexible hinges; the lower foot of the Z-shaped elastic link at the center is fixed to the upper surface of the fixed frame, and the upper foot is fixed to the lower surface of the floating frame; symmetrical flexible hinges are provided on the horizontal beam. A measuring beam is installed on the Z-shaped elastic connecting rod, and a semiconductor strain gauge is attached to the measuring beam. A terminal block is also fixed on the measuring beam of the semiconductor strain gauge, and the interface of the terminal block is connected to the semiconductor strain gauge through a wire.

[0007] Furthermore, the flexible hinge is a single-axis four-circular-arc flexible hinge; the main body of the flexible hinge is a square body, on which four circular through holes are symmetrically arranged vertically and horizontally. The circular through hole on the left side cuts a symmetrical channel to the left side and penetrates the left side wall. The circular through hole on the right side corresponds to the circular through hole on the left side, cuts a symmetrical channel to the right side and penetrates the right side wall, forming a single-axis four-circular-arc flexible hinge with a single axis running through the front and back at the center and circular arcs on the left and right sides.

[0008] Furthermore, the semiconductor strain gauge is a temperature-compensated semiconductor strain gauge, which is equipped with a temperature compensation resistor and a zero-point compensation resistor. After compensation, the temperature and zero-point drift of the semiconductor box balance do not exceed 1mV.

[0009] The test method of the semiconductor box balance for engine performance testing of the present invention includes the following steps: S10. Calibrate the semiconductor box balance; The semiconductor box balance is calibrated using a ground calibration system, and the obtained calibration formula is then input into the free jet wind tunnel measurement and control system. S20. Install a semiconductor box balance; Install the fixed frame of the semiconductor box balance on the support mechanism of the free jet wind tunnel through the support mechanism interface; install the model support plate on the floating frame through the model support plate interface; install the engine model on the model support plate; connect the engine model to the air supply pipeline; connect the wiring of the free jet wind tunnel measurement and control system to the semiconductor box balance through the terminal block interface. S30. Conduct the experiment; Semiconductor box balances are suitable for wind tunnel inflow Mach numbers of 4 to 7. When only the engine of the engine model is started, a static thrust test of the engine is performed; When only the free jet wind tunnel is activated, and there is free jet wind tunnel inflow, the engine drag performance test is performed; When the engine of the engine model and the free jet wind tunnel are started simultaneously, the engine thrust-to-drag ratio performance is tested. S40. Data processing; After the experiment is completed, the free jet wind tunnel measurement and control system will acquire the measurement data from the semiconductor box balance and combine it with the calibration formula for data processing and display.

[0010] The semiconductor box balance and its testing method for engine performance testing of the present invention have the following characteristics: 1. Semiconductor box balances have high rigidity and can withstand the additional forces and torques generated by the engine and auxiliary devices, as well as the aerodynamic impact forces during wind tunnel start-up or shutdown. 2. It can directly measure the thrust performance of the engine under both cold and hot conditions; 3. It has a fast response speed and can be used in pulse propulsion wind tunnels to measure time durations in milliseconds; 4. It can withstand the negative pressure and temperature environment of the wind tunnel high-pressure chamber.

[0011] The semiconductor box balance of the present invention, applied to engine performance testing, can achieve high-precision measurement of engine thrust performance and withstand the weight of a large-mass engine model and its accessories, as well as the atmospheric dynamic load impact during test start-up and shutdown. By using a high-sensitivity temperature-compensated semiconductor strain gauge to pick up the minute strain on the balance's elastic connecting rod, the measurement sensitivity is improved, the temperature effect is reduced or even eliminated, and the accuracy and stability of engine thrust performance measurement are improved.

[0012] In other words, the semiconductor box balance of this invention, applied to engine performance testing, effectively reduces interference between the various components of the balance and improves the balance's stiffness through its structural design. Furthermore, the balance strain sensor utilizes a temperature-compensated semiconductor strain gauge. On one hand, the high sensitivity of the semiconductor strain gauge improves the force measurement accuracy; on the other hand, the on-chip temperature self-compensation technology of the strain gauge reduces or even eliminates the temperature effect of the balance, thereby improving the accuracy and stability of engine thrust-drag performance measurement. Simultaneously, the test method of the semiconductor box balance of this invention for engine performance testing is simple and suitable for conducting engine static thrust testing, engine drag performance testing, and engine thrust-drag ratio performance testing. Attached Figure Description

[0013] Figure 1 This is an isometric view of the semiconductor box balance of the present invention used for engine performance testing; Figure 2 This is a front view of the semiconductor box balance of the present invention used for engine performance testing; Figure 3 This is a left view of the semiconductor box balance of the present invention used for engine performance testing; Figure 4 The present invention relates to a single-axis four-circular-arc flexible hinge in a semiconductor box balance used for engine performance testing. Figure 5a This is a front view of the balance patch of the semiconductor box balance used for engine performance testing according to the present invention. Figure 5b This is a top view of the balance patch of the semiconductor box balance used for engine performance testing according to the present invention. Figure 6 This is a schematic diagram of an engine performance testing device. Figure 7 This is a schematic diagram of the temperature-compensating semiconductor strain gauge used in the semiconductor box balance for engine performance testing according to the present invention. Figure 8 This is a schematic diagram illustrating the temperature self-compensation principle of the semiconductor box balance used in engine performance testing according to the present invention.

[0014] In the diagram: 1. Engine model; 2. Model support plate; 3. Semiconductor box balance; 4. Support mechanism; 5. Air supply pipeline; 301. Floating frame; 302. Fixed frame; 303. Z-shaped elastic link; 304. Flexible hinge; 305. Semiconductor strain gauge; 306. Terminal block; x, y, z represent the three-dimensional coordinate system of the semiconductor box balance. Detailed Implementation

[0015] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0016] The semiconductor box balance of the present invention, used for engine performance testing, is made of F141 and has a three-layer stacked structure. The upper layer is a floating frame 301 with a model support plate interface; the lower layer is a fixed frame 302 with a support mechanism interface; the middle layer is a measuring layer, including Z-shaped elastic links 303 located at the four corners and the center. The lower feet of the Z-shaped elastic links 303 at the four corners are fixed to the upper surface of the fixed frame 302, and the upper feet of the Z-shaped elastic links 303 are fixed to the lower surface of the floating frame 301 by flexible hinges 304. The lower foot of the central Z-shaped elastic link 303 is fixed to the upper surface of the fixed frame 302, and the upper foot is fixed to the lower surface of the floating frame 301. Flexible hinges 304 are provided on the horizontal beam with left and right symmetry. A measuring beam is provided on the Z-shaped elastic connecting rod 303, and a semiconductor strain gauge 305 is attached to the measuring beam. A terminal block 306 is also fixed on the measuring beam of the semiconductor strain gauge 305, and the interface of the terminal block 306 is connected to the semiconductor strain gauge 305 through a wire.

[0017] Furthermore, the flexible hinge 304 is a single-axis four-circular-arc flexible hinge; the main body of the flexible hinge 304 is a square body, and four circular through holes are symmetrically arranged on the square body, both vertically and horizontally. The circular through hole on the left side cuts a symmetrical channel to the left and through the left side wall, and the circular through hole on the right side corresponds to the circular through hole on the left side, cuts a symmetrical channel to the right and through the right side wall, forming a single-axis four-circular-arc flexible hinge with a single axis running through the front and back at the center and circular arcs on the left and right sides.

[0018] Furthermore, the semiconductor strain gauge 305 is a temperature self-compensating semiconductor strain gauge. The temperature self-compensating semiconductor strain gauge is equipped with a temperature compensation resistor and a zero-point compensation resistor. After compensation, the temperature and zero-point drift of the semiconductor box balance 3 do not exceed 1mV.

[0019] The test method of the semiconductor box balance for engine performance testing of the present invention includes the following steps: S10. Calibrate the semiconductor box balance 3; The semiconductor box balance 3 is calibrated using a ground calibration system, and the obtained calibration formula is input into the free jet wind tunnel measurement and control system. S20. Install semiconductor box balance 3; like Figure 6 As shown, the fixed frame 302 of the semiconductor box balance 3 is installed on the support mechanism 4 of the free jet wind tunnel through the support mechanism interface; the model support plate 2 is installed on the floating frame 301 through the model support plate interface; the engine model 1 is installed on the model support plate 2; the engine model 1 is connected to the air supply pipeline 5; the wiring of the free jet wind tunnel measurement and control system is connected to the semiconductor box balance 3 through the interface of the terminal block 306. S30. Conduct the experiment; The semiconductor box balance 3 is suitable for wind tunnel incoming Mach numbers of 4 to 7. When only the engine of engine model 1 is started, a static thrust test of the engine is performed; When only the free jet wind tunnel is activated, and there is free jet wind tunnel inflow, the engine drag performance test is performed; When the engine of engine model 1 and the free jet wind tunnel are started at the same time, the engine thrust-to-drag ratio performance test is carried out. S40. Data processing; After the experiment is completed, the free jet wind tunnel measurement and control system will acquire the measurement data from the semiconductor box balance 3 and combine it with the calibration formula for data processing and display.

[0020] Example 1:

[0021] Figure 1 This is an isometric view of the semiconductor box balance 3. Figure 2 and Figure 3These are the front and left views of the semiconductor box balance 3. The semiconductor box balance 3 consists of a floating frame 301 connected to the engine model 1, a fixed frame 302 connected to the support mechanism 4, and several Z-shaped elastic links 303 with flexible hinges 304. Semiconductor strain gauges 305 are attached to the measuring beams of the Z-shaped elastic links 303 to sense load information. To measure the normal force and pitch moment components, four Z-shaped elastic links 303 with rectangular cross-sections are arranged around the fixed frame 302; to measure the axial component, one Z-shaped elastic link 303 with a rectangular cross-section is arranged between the fixed frame 302 and the floating frame 301.

[0022] The Z-shaped elastic link 303 uses a single-axis four-circular-arc flexible hinge for load transfer. The structure of the single-axis four-circular-arc flexible hinge is as follows: Figure 4 As shown. The flexible hinge 304 is a reversible flexible support structure that enables frictionless, backlash-free, and smooth transmission. The flexible hinge 304 can only transmit the axial tension or compression of the Z-shaped elastic link 303, while excluding the action of forces in other directions. This ensures that the Z-shaped elastic link 303 is only subjected to the load of the component to be measured, achieving mechanical decomposition of force and torque.

[0023] Figure 5a , Figure 5b This is a diagram showing the mounting points for the semiconductor box balance 3. Twelve semiconductor strain gauges 305 with temperature self-compensation function are attached to the measuring beam of the Z-shaped elastic connecting rod 303. In the diagram, squares indicate the mounting positions of the semiconductor strain gauges 305, and ellipses indicate the mounting positions of the terminals 306. Strain gauges 1-4 are axial strain gauges, attached to the central vertical beam of the balance; strain gauges 5-12 are normal strain gauges. Strain gauges 1-4 are attached side-by-side on the front and rear sides of the axial sensing beam along the "X" direction, with each strain gauge positioned at the center of its respective sensing surface, and a 5mm spacing between any two strain gauges on the same surface. Strain gauges 5-12 are attached to the top and bottom sides of the normal sensing beam along the "Y" direction, with each strain gauge positioned at the center of its respective sensing surface. All semiconductor strain gauges 305 must be symmetrically attached front-to-back and top-to-bottom. The terminals 306 of the axial strain gauge are arranged nearby, and the terminals 306 of the normal strain gauge are attached to the inner surface of the corresponding sensitive beam along the "X" direction.

[0024] Figure 7This is a schematic diagram of a temperature-compensated semiconductor strain gauge. The Vs+1, Vs+2, Vs-, V+, and V- terminals of the semiconductor strain gauge 305 are the wiring terminals. The general specifications for the strain gauge leads are as follows: the power input terminal V+ is red, the V- terminal is blue, the signal output terminals Vs+1 and Vs+2 are yellow, and the Vs- terminal is black. The leads from the strain gauge to terminal 306 use the same insulated cable. The strain gauge number is marked on the end of each lead. The measurement bridge wiring should be laid out correctly (horizontally and vertically as much as possible) and free of cold solder joints.

[0025] Figure 8 This is a schematic diagram of the temperature self-compensation principle of a 305 semiconductor strain gauge, where R0 is the temperature compensation resistor, R01 and R02 are the zero-point compensation resistors, and R1, R2, R3, and R4 are the strain-sensitive resistors. +U i -U is the positive terminal of the strain gauge input voltage. i +U is the negative terminal of the strain gauge input voltage. 01 and +U 02 As the positive terminal of the strain gauge output voltage signal, +U is selected based on the zero-point compensation results. 01 or +U 02 One of them, -U0 is the negative terminal of the strain gauge output voltage signal, and after compensation, the balance temperature and zero drift do not exceed 1mV.

[0026] The semiconductor box balance 3 used for engine performance testing described in this article is only one embodiment. In fact, there are many balance structures that can realize the engine thrust performance testing function of this invention. Any simple modifications, changes, and equivalent structural changes made to the above embodiments based on the technical essence of this invention shall still fall within the protection scope of this invention.

Claims

1. A semiconductor box balance used for engine performance testing, characterized in that, The semiconductor box balance (3) is made of F141 and has a three-layer stacked structure. The upper layer is a floating frame (301) with a model support plate interface. The lower layer is a fixed frame (302) with a support mechanism interface. The middle layer is a measuring layer, including Z-shaped elastic links (303) located at the four corners and the center. The lower feet of the Z-shaped elastic links (303) at the four corners are fixed to the upper surface of the fixed frame (302), and the upper feet of the Z-shaped elastic links (303) are fixed to the lower surface of the floating frame (301) by flexible hinges (304). The lower foot of the Z-shaped elastic link (303) at the center is fixed to the upper surface of the fixed frame (302), and the upper foot is fixed to the lower surface of the floating frame (301). Flexible hinges (304) are provided on the horizontal beam with left and right symmetrical arrangement. A measuring beam is provided on the Z-shaped elastic link (303), a semiconductor strain gauge (305) is attached to the measuring beam, and a terminal block (306) is also fixed on the measuring beam. The interface of the terminal block (306) is connected to the semiconductor strain gauge (305) through a wire. The flexible hinge (304) is a single-axis four-circular-arc flexible hinge. The main body of the flexible hinge (304) is a square body with four circular through holes that are symmetrical in the upper and lower and left and right sides. The circular through hole on the left side cuts a symmetrical channel to the left side and passes through the left side wall. The circular through hole on the right side corresponds to the circular through hole on the left side, cuts a symmetrical channel to the right side and passes through the right side wall, forming a single-axis four-circular-arc flexible hinge with a single axis that runs through the front and back and circular arcs on the left and right sides.

2. The semiconductor box balance for engine performance testing according to claim 1, characterized in that, The semiconductor strain gauge (305) is a temperature self-compensating semiconductor strain gauge. The temperature self-compensating semiconductor strain gauge is equipped with a temperature compensation resistor and a zero-point compensation resistor. After compensation, the temperature and zero-point drift of the semiconductor box balance (3) do not exceed 1mV.

3. A test method for a semiconductor box balance used in engine performance testing, wherein the test is conducted based on the semiconductor box balance used in engine performance testing as described in any one of claims 1 to 2, characterized in that, Includes the following steps: S10. Calibrate the semiconductor box balance (3); The semiconductor box balance (3) is calibrated by the ground calibration system, and the obtained calibration formula is input into the free jet wind tunnel measurement and control system; S20. Install the semiconductor box balance (3); Install the fixed frame (302) of the semiconductor box balance (3) on the support mechanism (4) of the free jet wind tunnel through the support mechanism interface; install the model support plate (2) on the floating frame (301) through the model support plate interface; install the engine model (1) on the model support plate (2); connect the engine model (1) to the air supply pipeline (5); connect the circuit of the free jet wind tunnel measurement and control system to the semiconductor box balance (3) through the interface of the terminal block (306); S30. Conduct the experiment; Semiconductor box balance (3) is suitable for wind tunnel incoming Mach number 4 to Mach number 7; When only the engine of engine model (1) is started, the static thrust test of the engine is performed; When only the free jet wind tunnel is activated, and there is free jet wind tunnel inflow, the engine drag performance test is performed; When the engine of engine model (1) and the free jet wind tunnel are started simultaneously, the engine thrust ratio performance test is carried out. S40. Data processing; After the experiment is completed, the free jet wind tunnel measurement and control system will acquire the measurement data of the semiconductor box balance (3) and combine it with the calibration formula for data processing and display.

Images