A six-component high-precision micro-rolling torque measurement device and measurement method

Abstract

The present invention discloses a six-component high-precision micro-rolling torque measuring device, which relates to the technical field of aerospace wind tunnel force measurement tests. The device can simultaneously measure six aerodynamic force components with extremely different loads acting on a test model. The specific scheme is as follows: it includes a main balance element, a bearing, a model connecting sleeve, a balance support rod, an air intake pipe and an exhaust pipe; the main balance element includes a support rod end and a main balance element model end respectively located at two ends, the support rod end is connected to the balance support rod, the main balance element model end is connected to the stator of the bearing, and the rotor of the bearing is connected to the model connecting sleeve; a roll-resistance element is provided on the outer ring of the main balance element, the roll-resistance element includes a fixed end and a roll-resistance element model end, and the fixed end is connected to the main balance element model end; the six-component high-precision micro-rolling torque measuring device provided by the present invention can avoid repeated tests under the same test state, improve the accuracy of test data, and at the same time reduce the number of test vehicles and reduce the test cost.

Description

Technical Field

[0001] The present invention relates to the technical field of aerospace wind tunnel force measurement test, and more particularly to a six-component high-precision micro-rolling moment measurement device and a measurement method. Background Art

[0002] To meet the requirements for measuring the minute roll moments of miniaturized reentry vehicle test models, high-speed wind tunnel testing typically utilizes a single-component air-bearing-based balance combined with a large-scale six-component small roll moment measurement technique. The roll moment range of a single-component air-bearing balance is an order of magnitude smaller than that of a six-component balance, reaching a maximum of only 0.02 Nm. Through the rational combination and repeated verification of the single-component air-bearing balance and the six-component balance across different vehicle runs, moment measurements in the gram-centimeter range have been achieved.

[0003] The main disadvantage of this technical solution is that it cannot simultaneously measure the six aerodynamic components of the test model, which have extremely different loads. First, the same test state may need to be repeated. Due to the differences in test conditions caused by model disassembly and assembly, the measured values ​​are very small, which seriously affects the accuracy of the test data. Second, it increases the number of test vehicles. The calibration tests conducted by the single-component air flotation balance are all repeated, which is very costly. Third, the single-component air flotation balance is installed on the outside of the model, which is very prone to large temperature effects under high temperature test conditions, increasing the uncertainty of the test data. Fourth, the test plan is complex, making test and data correction and analysis difficult, which is prone to human error. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a six-component high-precision micro-rolling torque measurement device, which can simultaneously measure six aerodynamic force components with extremely different loads acting on a test model.

[0005] The above technical objectives of the present invention are achieved through the following technical solutions:

[0006] A six-component high-precision micro-roll torque measuring device includes a main balance element, a bearing, a model connecting sleeve, a balance support rod, an air intake pipe and an exhaust pipe;

[0007] The main balance element includes a strut end and a main balance element model end located at both ends respectively. The strut end is connected to the balance strut, and the main balance element model end is connected to the stator of the bearing. The rotor of the bearing is connected to the model connecting sleeve. A roll - resistance element is peripherally arranged around the main balance element. The roll - resistance element includes a fixed end and a roll - resistance element model end. The fixed end is connected to the main balance element model end, and the roll - resistance element model end is connected to the model connecting sleeve. An air intake passage communicating with the intake pipe is provided inside the main balance element. The number of exhaust pipes is at least 2. Exhaust passages communicating with the exhaust pipes and having the same number as the exhaust pipes are provided on the outer side of the main balance element. The exhaust passages are arranged symmetrically about the central axis of the main balance element. A test model is provided outside the model connecting sleeve. Sensitive elements are provided on the main balance element, and high - precision strain gauges are provided on the sensitive elements. Sensitive elements and resistance elements are also provided on the roll - resistance element, and high - precision strain gauges are provided on the sensitive elements.

[0008] As a preferred solution, the balance strut, the main balance element, the air - floating bearing and the model connecting sleeve are connected in sequence. The roll - resistance element and the air - floating bearing are respectively fixedly connected to the model connecting sleeve and the main balance element model end.

[0009] As a preferred solution, the bearing is a guide - type air - floating bearing, which is arranged inside the cavity of the test model and realizes the circumferential and axial free states through the high - pressure gas introduced through the intake pipe.

[0010] In the above - mentioned preferred solution, during the test process, the air - floating bearing does not rotate significantly, but small angular displacements and axial displacements occur, so that the roll - resistance element can generate sufficient deformation to achieve the purpose of measuring force.

[0011] As a preferred solution, there are two exhaust pipes, and the exhaust passages on the outer side of the main balance element are two bellows, and the two bellows are respectively connected to the two exhaust pipes.

[0012] In the above - mentioned preferred solution, there are two exhaust pipes in the figure. Looking from the right side of the balance strut, the two exhaust pipes and the intake pipe are in a "pin" shape to make full use of the internal space of the balance strut. In the main balance element in the left - hand area, the three channels are arranged side by side. That is, the air intake passage is located at the central axis position, and the two exhaust channels are symmetric about the central axis. Setting two exhaust pipes and two ventilation channels is to reduce the occupied space of the channels and the overall volume. In different implementation cases, an even number of exhaust channels can also be used, as long as they are symmetric about the central axis, so as to reduce the positive - negative symmetry of the main balance force - measuring components.

[0013] As a preferred solution, an axial through - hole is provided inside the main balance element.

[0014] In the above - mentioned preferred solution, air is introduced through the axial through - hole inside the main balance element to save space and enable the main balance sensitive element to have sufficient sensitivity.

[0015] As a preferred solution, the main balance support rod, the main balance element, the air bearing and the model connecting sleeve are connected in sequence, and the roll-resistance element and the air bearing are fixedly connected to the model connecting sleeve and the model end of the main balance element respectively.

[0016] As a preferred solution, the main balance element is a four-component balance used to measure lift, pitch moment, side force and yaw moment. A positioning boss and a sealing groove are provided at the model end of the main balance element, and the sealing groove cooperates with the sealing ring to achieve high-pressure air intake sealing; two sensitive elements are symmetrically arranged at the support rod end and the model end of the main balance element.

[0017] As a preferred solution, the roll-resistance element is a two-component ring balance structure, and the sensitive elements on the roll-resistance element are four roll measuring beams that are 90° to each other in the vertical and horizontal directions; the resistance measuring beams include four, and the resistance measuring beams are respectively arranged at the roots of the roll measuring beams near the model ends.

[0018] In the above preferred embodiment, the two-component ring balance structure is used to measure the resistance and the micro-rolling torque.

[0019] As a preferred solution, the roll measurement beam and the resistance measurement beam are connected in series and are perpendicular to each other to form an L-shaped structure. A high-precision strain gauge is provided on the measurement beam.

[0020] In the above solution, it is necessary to ensure that when resistance is generated, the rolling measurement beam is subjected to tensile force and cannot become unstable.

[0021] As a preferred solution, four symmetrically arranged limiting grooves are also provided on the rolling-resistance element.

[0022] In the above preferred solution, four symmetrically arranged limit slots are provided to prevent damage to the measuring element caused by overload during installation and testing.

[0023] The working principle of the six-component high-precision micro-rolling moment measurement device is as follows: through a clever structural layout design, four measuring bridges are formed by using strain gauges attached to the surface of the main balance element to achieve the measurement of lift, pitch moment, lateral force and yaw moment; air bearings are used to achieve an almost frictionless free state of the test model in the circumferential and axial directions, while transmitting the four aerodynamic forces measured by the main balance element acting on the test model; through the four measuring bridges arranged on the measuring beam of the roll-drag element, drag measurement is achieved while measuring the micro-rolling moment.

[0024] A six-component high-precision micro-rolling torque measurement method, based on the above-mentioned six-component high-precision micro-rolling torque measurement device, includes the following steps:

[0025] S1: Paste the strain gauges on the main balance element and the roll-resistance element to form a measuring bridge;

[0026] S2: Assemble the six-component, high-precision, micro-roll torque measurement device as follows: First, securely connect the ventilation line on the main balance element and perform an airtightness test, then connect it to the balance support rod. Next, sequentially place the roll-resistance element and the model connecting sleeve on the main balance element, slide them close to the support rod, and install the air bearing on the main balance element. Finally, install the roll-resistance element on the main balance element, then install the model connecting sleeve on the air bearing. Finally, secure the roll-resistance element to the model connecting sleeve.

[0027] S3: According to the test load and the working pressure conditions of the air bearing, the assembled six-component high-precision micro-rolling torque measurement device is calibrated on the ground to obtain the relationship matrix between the load and voltage signals;

[0028] S4: Install the calibrated measurement assembly in the test wind tunnel, then install the test model, ventilate according to the working pressure of the air bearing, and energize the measuring bridges of the balance to ensure that the air bearing works normally and the signal output of each bridge of the balance is normal;

[0029] S5: The test starts, and the voltage signals of each measuring bridge are collected. The voltage signals are converted back into aerodynamic values ​​through the relationship matrix calibrated in step S3, completing the simultaneous measurement of the six components of aerodynamic force.

[0030] In summary, the present invention has the following beneficial effects:

[0031] (1) The six-component high-precision micro-rolling torque measurement device provided by the present invention can avoid repeated tests under the same test conditions, thereby improving the accuracy of test data, reducing the number of test vehicles, and lowering test costs;

[0032] (2) All components of the measurement assembly of the six-component high-precision micro-rolling torque measurement device provided by the invention are arranged inside the model cavity, which effectively reduces the temperature effect under high-temperature test conditions and reduces the uncertainty of the test data;

[0033] (3) The six-component high-precision micro-rolling torque measurement device provided by the invention has a simple test scheme, does not require repeated assembly, and is easy to test, correct, and analyze data;

[0034] (4) The six-component high-precision micro-rolling moment measurement device provided by the invention can be reused. When the model shape changes but the load is similar, the corresponding wind tunnel test can be carried out by simply redesigning the model according to the interface of the model connecting sleeve. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 1 is a schematic structural diagram of a six-component high-precision micro-rolling torque measurement device according to an embodiment of the present invention;

[0036] Figure 2 This is a schematic structural diagram of the main balance component of an embodiment of the present invention;

[0037] Figure 3 This is a diagram of a measuring bridge of a master balance element of an embodiment;

[0038] Figure 4 is a schematic structural diagram of a roll-resistance element according to an embodiment of the present invention;

[0039] Figure 5 This is a bridge diagram of a roll-resistance element measurement according to an embodiment of the present invention;

[0040] in:

[0041] 1. Main balance element; 2. Bearing; 3. Model connecting sleeve; 4. Balance support rod; 5. Inlet pipe; 6. Exhaust pipe; 7. Roll-resistance element; 8. Bellows; 9. Sensitive element; 11. Support rod end; 12. Main balance element model end; 13. Sealing groove; 71. Fixed end; 72. Roll-resistance element model end; 73. Roll measurement beam; 74. Resistance measurement beam;

[0042] Figure 2 Among them: 1(2), 3(4), 5(6), 7(8), 9(10), 11(12), 13(14), 15(16) correspond to Figure 3 The strain gauges used in the measuring bridge;

[0043] Figure 4 Among them: 1(2), 3(4), 5(6), 7(8), 9(10), 11(12), 13(14), 15(16), 17(18), 19(20), 21(22), 23(24) correspond to Figure 5 Strain gauges used in each measuring bridge. DETAILED DESCRIPTION

[0044] This specification and claims do not distinguish components by name, but rather by functional differences. Throughout the specification and claims, the term "including" is open-ended and should be interpreted as "including, but not limited to." "Substantially" means that within an acceptable error range, a person skilled in the art can solve the technical problem and achieve the desired technical effect.

[0045] The directional terms such as up, down, left, right, etc. in this specification and claims are used in conjunction with the drawings to facilitate further explanation and make this application more convenient to understand, and do not limit this application. In different scenarios, up, down, left, right, inside and outside are all relative.

[0046] The present invention will be further described in detail below with reference to the accompanying drawings.

[0047] The six-component high-precision micro-rolling torque measurement device is as follows Figure 1 As shown, the main structure comprises a main balance element 1, an air bearing 2, a model connecting sleeve 3, a balance rod 4, an air intake pipe 5, and an exhaust pipe 6. The main balance element 1 has its rod end 11 connected to the rod via a flange and pinned, while the exhaust pipe end is flanged to the stator of the air bearing 2. The rolling resistance element is a flexible floating frame structure that encloses the main balance element 1. Its fixed end 71 is connected to the exhaust pipe end 12 of the main balance element, which in turn is connected to the exhaust pipe 3. The air bearing 2 is a guide rail type air bearing 2, which is circumferentially and axially free via high-pressure gas in the air intake pipe 5. Its rotor is flanged to the exhaust pipe 3, and its stator is connected to the exhaust pipe end 12 of the main balance element. The main balance element 1 has an internal axial through-hole as an air intake channel. Two exhaust pipes 6 are designed on the left and right sides, connected by two symmetrically arranged bellows 8, and lead out of the wind tunnel through the interior of the balance rod 4. The exhaust pipe 6 is sheathed on the exhaust pipe 3. The six-component high-precision micro-rolling torque measurement device is characterized in that the air bearing 2, main balance element 1 and rolling resistance element are all located inside the model; the air intake pipe 5 passes through the inside of the main balance, and the exhaust pipe 6 is led out through the bellows 8 arranged on both sides of the main balance element 1; the main balance element 1 is connected in series with the air bearing 2 and the model connecting sleeve 3, and the rolling resistance element is connected in parallel with the air bearing through the model connecting sleeve 3.

[0048] The structure of the main balance element 1 is as follows Figure 2 As shown, the model has a dumbbell-like shape, with a positioning boss and a sealing groove 13 at the model end, and an O-ring seal to achieve high-pressure air intake sealing. Its support rod end 11 and the model end are set at both ends, and two sensitive elements 9 are symmetrically arranged next to them. The sensitive elements 9 are equipped with high-precision strain gauges.

[0049] The rolling resistance element is designed as a ring balance structure, such as Figure 3 As shown, the sensitive element 9 is designed as four roll measurement beams 73, angled 90 degrees vertically and horizontally. Four resistance elements are located at the base of the roll measurement beams 73 near the model end. The fixed end 71 is connected to the outer flange of the main balance element model end 12 via a clamp. The roll measurement beams 73 and the resistance measurement beam 74 are connected in series to form an L-shaped structure. High-precision strain gauges are installed on the measurement beams. The roll resistance element also features four symmetrically arranged limit slots to prevent damage to the measuring element due to overload during installation and testing.

[0050] The working principle of the six-component high-precision micro-rolling moment measurement device is as follows: through a clever structural layout design, the main balance element 1 is used to measure four measuring bridges formed by strain gauges attached to its surface, thereby achieving the measurement of lift, pitching moment, lateral force and yaw moment; the air bearing 2 is used to achieve a free state of the test model with almost no friction in the circumferential and axial directions, while simultaneously transmitting the four aerodynamic forces acting on the test model measured by the main balance element 1; and through the four measuring bridges arranged on the measuring beam, resistance measurement is achieved while measuring the micro-rolling moment.

[0051] Working Principle: This invention utilizes a "4+2" combined measuring element to measure six aerodynamic force components. By cleverly exploiting the low friction of air-bearing guides and bearings, it achieves lossless transmission of aerodynamic forces in the roll and drag directions. This allows for precise measurement of minute roll moments using a circumferentially symmetrical L-shaped frame-type roll-drag element. Simultaneously, supported by a high-pressure gas film, the air bearing transfers the larger loads of the other four components on the test model to the main balance element for separate measurement. This effectively reduces interference from these large loads on the minute roll moment measurement, enabling simultaneous measurement of six aerodynamic force components with vastly different loads.

[0052] The working process and measurement method of the six-component high-precision micro-rolling torque measurement device are as follows:

[0053] (1) After each component is processed and manufactured, Figure 2 and Figure 3 The measuring bridge shown is used to attach strain gauges to the main balance element 1 and the rolling resistance element;

[0054] (2) The six-component high-precision micro-rolling torque measuring device is assembled according to the following steps: first, the ventilation pipe on the main balance element 1 is securely connected and an airtightness test is performed, and then it is connected to the balance support rod 4. Next, the rolling resistance element and the model connecting sleeve 3 are sequentially placed on the main balance element 1, and slid to a position close to the support rod, and the air bearing 2 is installed on the main balance element 1. Then, the rolling resistance element is installed on the main balance element 1, and then the model connecting sleeve 3 is installed on the air bearing 2. Finally, the rolling resistance element and the model connecting sleeve 3 are fixed;

[0055] (3) According to the load of the test state and the working pressure conditions of the air bearing 2, the ventilation state of the assembled six-component high-precision micro-rolling torque measurement device is calibrated on the ground to obtain the relationship matrix between the load and voltage signals;

[0056] (4) Install the calibrated measurement assembly in the test wind tunnel, then install the test model, ventilate according to the working pressure of the air bearing 2, and energize the measuring bridges of the balance to ensure that the air bearing 2 works normally and the signal output of each bridge of the balance is normal;

[0057] (5) The test is started, and the voltage signals of each measuring bridge are collected. The voltage signals are converted back into aerodynamic values ​​through the relationship matrix calibrated in step (3), completing the simultaneous measurement of the six components of aerodynamic force.

[0058] This specific embodiment is merely an explanation of the present invention and is not intended to limit the present invention. After reading this specification, those skilled in the art may make non-creative modifications to this embodiment as needed. However, as long as such modifications are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A six-component high-precision micro-rolling torque measurement device, characterized in that: It comprises a main balance element (1), a bearing (2), a model connecting sleeve (3), a balance support rod (4), an air inlet pipe (5) and an exhaust pipe (6); The main balance element (1) comprises a support rod end (11) and a main balance element model end (12) respectively located at two ends, the support rod end (11) is connected to the balance support rod (4), the main balance element model end (12) is connected to the stator of the bearing (2), and the rotor of the bearing (2) is connected to the model connecting sleeve (3); a roll-resistance element (7) is provided on the outer ring of the main balance element (1), the roll-resistance element (7) comprises a fixed end (71) and a roll-resistance element model end (72), the fixed end (71) is connected to the main balance element model end (12), and the roll-resistance element model end (72) is connected to the model connecting sleeve (3) connection; an air intake channel connected to an air intake pipe (5) is provided inside the main balance element (1), the number of exhaust pipes (6) is at least two, an exhaust channel connected to the exhaust pipe (6) and the same number as the exhaust pipe (6) is provided outside the main balance element (1), and the exhaust channels are symmetrically arranged along the central axis of the main balance element (1); a test model is provided outside the model connecting sleeve (3); a sensitive element (9) is provided on the main balance element (1), and a high-precision strain gauge is provided on the sensitive element (9); a sensitive element (9) and a resistance element are also provided on the roll-resistance element (7), and a high-precision strain gauge is provided on the sensitive element (9); The balance support rod (4), the main balance element (1), the air bearing (2) and the model connecting sleeve (3) are connected in sequence, and the rolling-resistance element (7) and the air bearing (2) are respectively fixed to the model connecting sleeve (3) and the main balance element model end (12); The bearing (2) is a guide rail air-floating bearing (2), which is arranged inside the cavity of the test model and is free in the circumferential and axial directions by high-pressure gas introduced through the air inlet pipe (5); The main balance element (1) is a four-component balance used to measure lift, pitch moment, side force and yaw moment. The main balance element model end (12) is provided with a positioning boss and a sealing groove (13). The sealing groove (13) cooperates with a sealing ring to achieve high-pressure air intake sealing. Two sensitive elements (9) are symmetrically provided at the support rod end (11) and the main balance element model end (12). The roll-resistance element (7) is a two-component ring balance structure. The sensitive element (9) on the roll-resistance element (7) is four roll-measurement beams (73) with 90° in the longitudinal and transverse directions. The resistance measurement beams (74) include four, and the resistance measurement beams (74) are respectively arranged at the roots of the roll-measurement beams (73) near the model ends. The roll measurement beam (73) and the resistance measurement beam (74) are connected in series and are perpendicular to each other to form an L-shaped structure. A high-precision strain gauge is provided on the measurement beam.

2. The six-component high-precision micro-rolling torque measurement device according to claim 1, characterized in that: There are two exhaust pipes (6), and the exhaust passage outside the main balance element (1) is two bellows (8), and the two bellows (8) are respectively connected to the two exhaust pipes (6).

3. The six-component high-precision micro-rolling torque measurement device according to claim 2, characterized in that: The fixed end (71) is connected to the flange outer column of the main balance element model end (12) through a hoop.

4. The six-component high-precision micro-rolling torque measurement device according to claim 3, characterized in that: The rolling-resistance element (7) is also provided with four symmetrically arranged limiting grooves.

5. A six-component high-precision micro-rolling torque measurement method, based on the six-component high-precision micro-rolling torque measurement device according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1: Paste strain gauges on the main balance element (1) and the roll-resistance element (7) to form a measuring bridge; S2: The six-component high-precision micro-rolling torque measuring device is assembled according to the following steps: first, the ventilation pipe on the main balance element (1) is reliably connected and an airtightness test is performed, and then it is connected to the balance support rod (4); then, the roll-resistance element (7) and the model connecting sleeve (3) are sequentially sleeved on the main balance element (1), and slid to a position close to the support rod, and the air bearing (2) is installed on the main balance element (1); then, the roll-resistance element (7) is installed on the main balance element (1), and then the model connecting sleeve (3) is installed on the air bearing (2), and finally, the roll-resistance element (7) and the model connecting sleeve (3) are fixed; S3: According to the load in the test state and the working pressure condition of the air bearing (2), the assembled six-component high-precision micro-rolling torque measuring device is calibrated on the ground to obtain the relationship matrix between the load and the voltage signal; S4: Install the calibrated measurement assembly in the test wind tunnel, then install the test model, ventilate according to the working pressure of the air bearing (2), and energize the measuring bridges of the balance to make the air bearing (2) work normally and the signal output of each bridge of the balance normal; S5: The test starts, and the voltage signals of each measuring bridge are collected. The voltage signals are converted back into aerodynamic values ​​through the relationship matrix calibrated in step S3, completing the simultaneous measurement of the six components of aerodynamic force.

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