CN106768801B - High-precision double-rotating-shaft side slip angle conversion device for wind tunnel test - Google Patents
High-precision double-rotating-shaft side slip angle conversion device for wind tunnel test Download PDFInfo
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- CN106768801B CN106768801B CN201611092986.5A CN201611092986A CN106768801B CN 106768801 B CN106768801 B CN 106768801B CN 201611092986 A CN201611092986 A CN 201611092986A CN 106768801 B CN106768801 B CN 106768801B
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Abstract
A high-precision double-rotating shaft type sideslip angle conversion device for wind tunnel test aims to realize continuous conversion of sideslip angles of wind tunnel test, so that wind tunnel test efficiency is improved. The device comprises a first rotating shaft, a second rotating shaft, an expansion sleeve locking unit and an encoder, wherein the first rotating shaft is L-shaped, a horizontal part of the L-shaped rotating shaft and the rotating shaft are respectively fixed in two shaft connecting pieces through self-lubricating bearings, a first worm wheel of a first worm wheel and worm transmission group is fixed on the first rotating shaft, a second worm wheel of the second worm wheel and worm transmission group is fixed on the second rotating shaft, and the expansion sleeve locking unit is respectively arranged at the end part of the horizontal part of the first rotating shaft and one end of the second rotating shaft. The invention realizes continuous conversion of yaw angles in a range through rotation of two shafts of the yaw angle sensor. The encoders are arranged on the two shafts, so that the accuracy of angle transformation is ensured, and meanwhile, the expansion sleeve locking units are arranged at the end parts of the two shafts, so that the stability of the two shafts in a blowing test is ensured.
Description
Technical field:
the invention relates to a yaw angle conversion device of a wind tunnel test model, which meets wind tunnel test requirements under different attitude angles, belongs to the technical field of aero-aerodynamic wind tunnel tests, and particularly relates to a high-precision double-rotating-shaft side slip angle conversion device for wind tunnel tests.
The background technology is as follows:
aerodynamic is a specialized discipline for studying the laws of air motion and air-object interactions when there is relative motion between air and an object. In the aviation field, the principle that an aircraft (mainly an airplane, a helicopter and a missile are also included) flies in the atmosphere is mainly studied, and the change rule of aerodynamic force acting on the aircraft along with basic factors such as the geometrical shape, the flying attitude, the Mach number, the Reynolds number and the like of the aircraft and the geometrical characteristics of the aircraft and parts required by certain aerodynamic performance are met. The wind tunnel test is to study the flow characteristics of air, the interaction rule of air and the relative motion of objects and other aerodynamic problems by adopting a test method, namely, simply fixing a model or a real object of an aircraft in a ground artificial environment (wind tunnel) according to the relative motion principle, artificially manufacturing airflow to simulate various complex flight states in the air, and acquiring experimental data.
In the wind tunnel test process, the posture of the model is required to be transformed so as to obtain aerodynamic force data under different conditions, and the model sideslip angle transformation is one of important contents. At present, a fixed block type sideslip conversion connector shown in the figure 1 is commonly adopted in a wind tunnel, the weight of the fixed block connector in the current wind tunnel is large, the replacement is laborious, and only a few of fixed block connectors are generally processed; meanwhile, the angular density of the fixed block joint is 1 DEG at the minimum, and true values of other concerned points except the fixed angle cannot be obtained. The mode can only realize few sideslip angle changes, one angle corresponds to one fixed block joint, and time and labor are wasted; the blocking degree and the rigidity of the different sideslip angle connectors are inconsistent, so that the wind tunnel flow field control and the elastic angle correction are affected; meanwhile, the locating key of the fixed block type sideslip joint is not easy to find and repair after being worn, so that sideslip angle errors are generated, a plurality of screws are required to be screwed down when a finished expansion sleeve locking part of the fixed block type sideslip joint is fastened, special nail withdrawing is required when the finished expansion sleeve locking part is loosened, and the operation is complex.
The invention comprises the following steps:
the invention provides a high-precision double-rotating-shaft side slip angle conversion device for a wind tunnel test, which aims to realize continuous conversion of the side slip angle of the wind tunnel test and replace a current fixed block type side slip angle connector so as to improve the efficiency of the wind tunnel test.
The invention discloses a high-precision double-rotating-shaft side slip angle conversion device for wind tunnel test, which comprises a first rotating shaft, a second rotating shaft transmission unit, an expansion sleeve locking unit and a measuring unit, wherein the first rotating shaft is L-shaped, a horizontal part of the L-shaped rotating shaft and the rotating shaft are respectively fixed in two shaft connecting pieces through self-lubricating bearings, the transmission unit comprises a first shaft worm gear transmission group and a second shaft worm gear transmission group, a first worm gear of the first shaft worm gear transmission group is fixed on the first rotating shaft, a second worm gear of the second shaft worm gear transmission group is fixed on the second rotating shaft, and the expansion sleeve locking unit is respectively arranged at the end part of the horizontal part of the first rotating shaft and one end of the second rotating shaft.
As a further improvement of the invention, the expansion sleeve locking unit comprises an expansion sleeve outer sleeve, an expansion sleeve inner sleeve, an expansion sleeve cover and an expansion sleeve seat, wherein the expansion sleeve outer sleeve is sleeved outside the expansion sleeve inner sleeve, the expansion sleeve cover is arranged outside the expansion sleeve inner sleeve through a bearing, and the expansion sleeve seat is arranged at the outer end part of the expansion sleeve inner sleeve. Thereby forming an expansion sleeve locking unit, and locking and positioning the first rotating shaft and the second rotating shaft to stop the rotation of the two shafts.
As a further development of the invention, the measuring unit is an encoder. The rotation angles of the first rotation shaft and the second rotation shaft can be detected rapidly and accurately through the encoder.
As a further improvement of the invention, one end of the first worm gear and worm transmission group and one end of the second worm gear and worm transmission group are respectively provided with a handle. The first worm and the second worm are convenient to rotate by rotating the handle, so that the two shafts are driven to rotate.
As a further improvement of the present invention, a fairing is connected to a vertical portion constituting the first rotation shaft. The airflow is blocked by carding through the fairing, so that the device can fly smoothly in the wind tunnel.
As a further improvement of the invention, a thrust bearing is arranged on the first rotating shaft. The thrust bearing is used for bearing the axial force applied to the rotating shaft.
As a further improvement of the invention, the end part of the horizontal part of the first rotating shaft is provided with a rectifying cone, and the tail part of the rectifying cone is inserted into the expansion sleeve seat. The interference of the windward side of the wind tunnel experimental mechanism is reduced through the rectifying cone, and the rotating shaft II is also connected with the supporting rod and the model related to the wind tunnel experimental mechanism, so that the model is windward, the end part of the model is not required to be provided with the rectifying cone, and the model is a scaling model of aircrafts such as airplanes or missiles.
The beneficial effects of the invention are as follows: the invention is provided with two rotating shafts which are respectively connected in series in the two shaft connecting pieces through self-lubricating bearings and can respectively rotate around the axes of the two rotating shafts, and the two rotating shafts realize continuous conversion of yaw angles in a range of measurement ranges, in particular to continuous conversion of any angle in an angle range of 0-8 degrees through the rotation of the two rotating shafts. The yaw angle continuous transformation can acquire the true value of any attention point on the test curve, encrypts the discrete test points, overcomes the error caused by the fact that the fixed block type sideslip angle joint can only interpolate by a few points to acquire the test curve, and improves the accuracy of wind tunnel test data. And the encoders are arranged on each rotating shaft, so that the accuracy of angle transformation is ensured, and meanwhile, the ends of the two rotating shafts are provided with expansion sleeve locking units, so that the stability of the first rotating shaft and the second rotating shaft in a blowing test is ensured. The device can obtain any sideslip angle in the range, and is simple and convenient to operate and high in reliability; the two rotating shafts are installed by self-lubricating bearings, so that the structure size is small, the blocking degree is small, and the maintenance is free; the transmission unit of the invention adopts a double-lead worm gear transmission group, the backlash of which is easy to adjust, and the assembly and maintenance are convenient; the invention adopts the expansion sleeve locking unit to lock and position the rotation of the two shafts, and in the concrete operation, only the expansion sleeve seat is required to rotate forward and backward to fasten the two shafts or loosen the fastening of the two shafts, thereby the operation is convenient and quick, and the time and the labor are saved.
Description of the drawings:
FIG. 1 is a schematic view of a conventional 8 degree fixed block joint;
FIG. 2 is a schematic cross-sectional view of the present invention;
FIG. 3 is a cross-sectional view of A-A of FIG. 1;
FIG. 4 is a cross-sectional view of B-B of FIG. 1;
FIG. 5 is a schematic view of the structure of the expansion shell locking unit;
fig. 6 is a schematic view of an inner sleeve of an expansion sleeve.
The specific embodiment is as follows:
the transformation device is used for bearing and fixing the aircraft model in wind tunnel experiments, and the purpose of transforming the angle of the aircraft model in the wind tunnel is achieved through the angle transformation of the transformation device in the wind tunnel.
Referring to fig. 2, 3 and 4, the high-precision double-rotating shaft sideslip angle conversion device for wind tunnel test comprises a first rotating shaft 1, a second rotating shaft 7, a transmission unit, an expansion sleeve locking unit 3 and a measuring unit 4, wherein the first rotating shaft 1 is L-shaped, a horizontal part forming the L shape and the second rotating shaft 7 are respectively fixed in a two-shaft connecting piece 6 through self-lubricating bearings 8, the axis of the horizontal part of the first rotating shaft 1 is not parallel to the axis of the second rotating shaft 7, an included angle between the axis of the horizontal part and the axis of the second rotating shaft is 8 degrees, the transmission unit comprises a first worm gear transmission group and a second worm gear transmission group, a first worm gear 10 of the first worm gear transmission group is fixed on the first rotating shaft 1, a second worm gear 11 of the second worm gear transmission group is fixed on the second rotating shaft 7, and the expansion sleeve locking unit 3 is respectively arranged at the end part of the horizontal part of the first rotating shaft 1 and one end of the second rotating shaft 7. One end of a worm 2 of the first worm gear and worm transmission group and one end of a worm 19 of the second worm gear and worm transmission group are respectively provided with a handle 12. A fairing 5 is connected to a vertical portion constituting the first rotary shaft 1. The first rotating shaft 1 is provided with a thrust bearing 18, and the thrust bearing 18 is arranged at the corner of the first rotating shaft 1. The measuring unit 4 is an encoder.
Referring to fig. 2, 5 and 6, the expansion sleeve locking unit 3 includes an expansion sleeve outer sleeve 13, an expansion sleeve inner sleeve 14, an expansion sleeve cover 15 and an expansion sleeve seat 17, the expansion sleeve outer sleeve 13 is sleeved outside the expansion sleeve inner sleeve 14, the expansion sleeve cover 15 is arranged outside the expansion sleeve inner sleeve 14 through a bearing 16, and the expansion sleeve seat 17 is arranged at the outer end of the expansion sleeve inner sleeve 14. The end part of the horizontal part of the first rotating shaft 1 is provided with a rectifying cone 9, and the tail part of the rectifying cone 9 is inserted into an expansion sleeve seat 17.
The invention relates to a wind tunnel test model posture conversion device, which is a 2-degree-of-freedom mechanism capable of continuously converting sideslip angles. The device combines alpha angle change of a wind tunnel attack angle mechanism, and realizes sideslip angle change through rotation movement of two shafts, namely a first rotating shaft 1 and a second rotating shaft 7. When the second rotating shaft 4 rotates by an angle gamma 1 from the vertical state, the second rotating shaft 7 is projected in the X-Y and X-Z planes respectively, and the included angles between the projection and the X-Y and X-Z axes are the attack angle alpha and the yaw angle beta. Is obtained by geometric relationship
According to the geometric relationship, there are
Wherein a is the projection length of the axis of the second rotating shaft 7 on the X-Y plane of the wind tunnel; b is the projection length of the second rotating shaft 7 on the Y-Z plane of the wind tunnel in a horizontal or vertical state; alpha is the angle of attack; beta is the yaw angle; γ1 is the angle of rotation of the dual spindle around axis one (the central axis of wind tunnel X) from the normal pre-biased 8 ° angle of attack vertical position.
Thus, the angle of attack walking amount and the axis rotation amount at the corresponding yaw angle can be obtained, and then the model of the device can be leveled by rotating the rotation shaft II 7. Thus, the attack angle of the attack angle mechanism and the angles of the double rotating shafts (the first rotating shaft 1 and the second rotating shaft 7) are changed, and the change of the yaw angle of the model is realized.
The operation process of the whole device is as follows:
according to the yaw angle and direction to be converted, the stroke value of the wind tunnel attack angle mechanism and the angle values required to rotate the first rotating shaft 1 and the second rotating shaft 7 are determined (pre-calibration). The first worm gear transmission group of the first shaft is utilized to drive the first rotating shaft 1 to rotate, so that the encoder indication value on the first rotating shaft 1 corresponds to the early calibration value, the expansion sleeve locking unit 3 at the end part of the first rotating shaft 1 is locked, and the first rotating shaft 1 stops rotating. And adjusting the stroke of the attack angle mechanism according to the value of the early calibration table to enable the axis of the second rotating shaft 7 to be in the horizontal plane. And the second worm and gear transmission group of the regulating shaft is regulated to ensure that the rolling angle of the model is zero (horizontal), wherein the zero rolling angle of the model means that corresponding points of wings or missile wings on two sides of the aircraft model are at the same height, at the moment, the reading of an encoder on the second rotary shaft 7 is recorded for subsequent reference, and the expansion sleeve locking unit 3 at the end part of the second rotary shaft 7 is locked to stop the rotation of the second rotary shaft 7. After the above work is completed, the test can be performed.
Claims (5)
1. The high-precision double-rotating-shaft side slip angle conversion device for wind tunnel test comprises a first rotating shaft (1), a second rotating shaft (7), a transmission unit, an expansion sleeve locking unit (3) and a measurement unit (4), wherein the first rotating shaft (1) is L-shaped, a horizontal part forming the L shape and the second rotating shaft (7) are respectively fixed in a two-shaft connecting piece (6) through self-lubricating bearings (8), the transmission unit comprises a first worm and gear transmission group and a second worm and gear transmission group, a first worm wheel (10) of the first worm and gear transmission group is fixed on the first rotating shaft (1), a second worm wheel (11) of the second worm and gear transmission group is fixed on the second rotating shaft (7), and the expansion sleeve locking unit (3) is respectively arranged at the end part of the horizontal part of the first rotating shaft (1) and one end of the second rotating shaft (7);
the expansion sleeve locking unit (3) comprises an expansion sleeve outer sleeve (13), an expansion sleeve inner sleeve (14), an expansion sleeve cover (15) and an expansion sleeve seat (17), wherein the expansion sleeve outer sleeve (13) is sleeved outside the expansion sleeve inner sleeve (14), the expansion sleeve cover (15) is arranged outside the expansion sleeve inner sleeve (14) through a bearing (16), and the expansion sleeve seat (17) is arranged at the outer end part of the expansion sleeve inner sleeve (14);
the end part of the horizontal part of the first rotating shaft (1) is provided with a rectifying cone (9), and the tail part of the rectifying cone (9) is inserted into an expansion sleeve seat (17);
the conversion device is a 2-degree-of-freedom mechanism capable of continuously converting sideslip angles, and the sideslip angle conversion is realized through the rotary motion of a first rotary shaft (1) and a second rotary shaft (7) by combining alpha angle change of a wind tunnel attack angle mechanism, and can be obtained through a geometric relationship:
according to the geometric relationship, there are:
wherein a is the projection length of the two axes of the rotating shaft on the X-Y plane of the wind tunnel; b is the projection length of the second rotating shaft in the horizontal or vertical state on the Y-Z plane of the wind tunnel; alpha is the angle of attack; beta is the yaw angle; γ1 is the angle of rotation of the rotation axis II around the rotation axis I from the vertical position of the positive pre-deflection angle of 8 degrees;
therefore, the attack angle walking amount and the rotation axis rotation amount under the corresponding yaw angle are obtained, and then the wind tunnel test model of the device is leveled by rotating the rotation axis II; the angle of attack of the attack angle mechanism and the angle of the double rotating shafts are changed, so that the yaw angle of the wind tunnel test model is changed.
2. The high-precision double-rotating-shaft side slip angle conversion device for wind tunnel test as claimed in claim 1, wherein: the measuring unit (4) is an encoder.
3. The high-precision double-rotating-shaft side slip angle conversion device for wind tunnel test as claimed in claim 1, wherein: one end of a first worm (2) of the first worm gear and worm transmission group and one end of a second worm (19) of the second worm gear and worm transmission group are respectively provided with a handle (12).
4. The high-precision double-rotating-shaft side slip angle conversion device for wind tunnel test as claimed in claim 1, wherein: a fairing (5) is connected to the vertical part of the first rotating shaft (1).
5. The high-precision double-rotating-shaft side slip angle conversion device for wind tunnel test as claimed in claim 1, wherein: a thrust bearing (18) is arranged on the first rotating shaft (1).
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| Application Number | Priority Date | Filing Date | Title |
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| CN201611092986.5A CN106768801B (en) | 2016-12-02 | 2016-12-02 | High-precision double-rotating-shaft side slip angle conversion device for wind tunnel test |
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| CN201611092986.5A CN106768801B (en) | 2016-12-02 | 2016-12-02 | High-precision double-rotating-shaft side slip angle conversion device for wind tunnel test |
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| CN106768801B true CN106768801B (en) | 2023-06-06 |
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Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN107450601A (en) * | 2017-08-02 | 2017-12-08 | 中国航空工业集团公司沈阳空气动力研究所 | A kind of change yaw angle mechanism suitable for high-speed wind tunnel |
| CN108760221B (en) * | 2018-05-31 | 2020-05-19 | 北京空天技术研究所 | Wind tunnel test guiding device |
| CN112798217B (en) * | 2021-03-23 | 2021-06-22 | 中国空气动力研究与发展中心高速空气动力研究所 | Follow-up compensation mechanism for wind tunnel test with continuously variable sideslip angle |
| CN114279674B (en) * | 2021-12-29 | 2023-07-21 | 中国空气动力研究与发展中心高速空气动力研究所 | Double-rotating-shaft supporting mechanism with changeable front shaft |
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