阅读说明：本技术 一种旋翼尾流spiv测量同步移测机构和锁相测量方法 (Rotor wake flow SPIV measurement synchronous movement measuring mechanism and phase-locked measuring method ) 是由 齐中阳 于 2021-08-25 设计创作，主要内容包括：本发明公开了一种旋翼尾流SPIV测量同步移测机构和锁相测量方法,结构中的结构支架上安装有旋翼模型、传感器、激光头和摄像装置,分别用于进行旋翼尾流测量、旋翼相位锁定、照亮旋翼尾流的测量区域内的示踪粒子；锁相测量方法对观测区域内的示踪粒子进行捕捉,得到观测区域的速度场,锁相测量方法针对测量区域进行对焦和标定,对相位角的转轴标定点进行锁定,针对测量区域照亮示踪粒子并进行数据采集和数据分析,直到全部测量区域的数据采集完毕。本发明结合了相位锁定测量和相位平均技术,实现了伪时间解析的三维速度场测量并抑制了瞬态SPIV测量的较高误差问题,实现了指定相位角的测量,得到准确的流场分析结果。(The invention discloses a synchronous measurement mechanism and a phase-locked measurement method for rotor wake flow SPIV (spin flow induced transient) measurement.A rotor model, a sensor, a laser head and a camera device are arranged on a structural support in the structure and are respectively used for rotor wake flow measurement, rotor phase locking and rotor wake flow lightening of tracer particles in a measurement area of the rotor wake flow; the phase-locking measurement method captures the tracer particles in the observation area to obtain the velocity field of the observation area, focuses and calibrates the measurement area, locks the calibration point of the rotating shaft of the phase angle, illuminates the tracer particles for the measurement area, and performs data acquisition and data analysis until the data acquisition of all the measurement areas is completed. The invention combines the phase locking measurement and the phase averaging technology, realizes the three-dimensional velocity field measurement of pseudo-time analysis, restrains the higher error problem of transient SPIV measurement, realizes the measurement of the specified phase angle and obtains the accurate flow field analysis result.)

1. The utility model provides a rotor wake SPIV measures synchronous moving survey mechanism which characterized in that, includes a structural support, installs rotor model, sensor, laser head and camera device on structural support, wherein:

the rotor model is used for measuring rotor wake flow;

a sensor for rotor phase locking;

a laser head for illuminating trace particles within a measurement region of the rotor wake;

the camera device is used for capturing the trace particles in the observation area to obtain a velocity field of the observation area;

the laser head and the camera device move synchronously under the action of the guide rail driving motor to acquire data of the tracer particles.

2. The rotor wing wake flow SPIV measurement synchronous moving mechanism according to claim 1, characterized in that a driving guide rail and a driving motor are installed on the structural support, the driving guide rail is arranged along the vertical direction, the camera device and the laser head are respectively installed on the driving guide rail, and are driven by the driving motor to synchronously move upwards or downwards along the vertical direction.

3. The rotor wake SPIV measurement synchronous movement mechanism of claim 1, wherein the camera device comprises two CCD cameras.

4. The rotor wake SPIV measurement synchronous moving measurement mechanism according to claim 1, 2 or 3, characterized in that the sensor is arranged on the fixed bracket and is in the same horizontal plane with the rotor rotation shaft calibration point, and the sensor locks the rotation shaft calibration point.

5. A phase-locked measurement method for rotor wake flow (SPIV) measurement is characterized by specifically comprising the following steps of: focusing and calibrating a measurement area, starting a rotor model to rotate, generating rotor wake flow, and scattering tracer particles; determining a phase angle measured by rotor wake flow, locking a rotating shaft calibration point of the phase angle through a sensor, synchronously triggering a laser light source and a camera device each time the rotor rotates to the measured phase angle, illuminating trace particles aiming at a measurement area and carrying out data acquisition; repeatedly acquiring the locking phase for multiple times until the data condition of subsequent analysis is met; controlling a driving motor to work, enabling a camera device and a laser head to move synchronously, automatically switching a measurement area, locking a measurement phase angle, and triggering the camera device to acquire data of the measurement area; and the above steps are circularly carried out until the data acquisition of all the measurement areas is finished.

6. The method for measuring the lock of the rotor wing wake SPIV according to claim 5, characterized in that the camera device comprises two CCD cameras, the CCD camera and the laser head are respectively and fixedly arranged on a CCD camera supporting rod and a laser head supporting rod, and the driving motor controls the CCD camera supporting rod and the laser head supporting rod to move.

Technical Field

The invention relates to a synchronous shift measurement mechanism and a phase-locked measurement method, in particular to a rotor wing wake flow SPIV measurement synchronous shift measurement mechanism and a phase-locked measurement method.

Background

The rotor serves as the main lift and maneuvering component of the helicopter, and its wake structure has a direct impact on the flight performance and reliability of the helicopter. Because the rotor wake field contains various complex aerodynamic characteristics, such as the overall rotation, unsteadiness, nonlinearity, three-dimensional effect of the flow field, the tip vortex structure in the flow field, the blade-vortex interference, the dynamic separation of the local area of the blade, and the like, the experimental measurement of the flow structure is very difficult.

The SPIV (stereo partial Image velocimetry) technology is a flow observation technology which uniformly spreads particles with the density similar to that of fluid in the fluid, collects Particle images in the same observation area illuminated by a laser sheet by adopting the off-axis arrangement of two CCD cameras by utilizing the principle of stereo vision, and finally obtains the Particle space displacement information of the observation area by carrying out a series of calculations such as cross-correlation on the collected Particle images. Therefore, SPIV is an experimental measurement method capable of measuring a three-component velocity field on a two-dimensional section in a flow field, and high-precision rotor wake space-time evolution velocity field data can be obtained.

In the process of measuring rotor wake flow by SPIV, in order to obtain the flowing global characteristic and the spatial-temporal evolution characteristic, a plurality of stations are often required to be selected along the downstream direction to measure the two-dimensional tangent plane three-component velocity field. According to the measurement requirement of the SPIV technology, the focal lengths of the two CCD cameras and the laser sheet need to be adjusted to coincide with a measurement tangent plane, then calibration is carried out, and the adjusting and calibrating process is difficult and complicated. At present, in the measurement process of rotor wake flow SPIV, each measurement station needs to be adjusted and calibrated once, so that the experiment difficulty is high, and the efficiency is low. In addition, the prior art also has the defects of high rotating speed of the rotor, limited SPIV time analysis capability and the like, and the wake flow characteristic of the rotor cannot be accurately depicted.

Disclosure of Invention

The invention aims to provide a rotor wing wake flow SPIV measurement synchronous movement measuring mechanism and a phase-locked measuring method, which can realize the adjustment and calibration of two CCD cameras and laser sheets at one time, ensure that the calibrated cameras and laser sheet system synchronously and automatically move and measure all stations according to the movement, and solve the defects in the prior art; meanwhile, the problems of high rotating speed of a rotor wing and limitation of SPIV time resolution capability are solved by combining phase locking and SPIV measurement technologies, the pseudo-time-resolved three-dimensional speed field measurement is realized, and the problem of higher error of transient SPIV measurement is restrained.

The invention is realized by adopting the following technical scheme:

the utility model provides a rotor wake SPIV measures synchronous moving survey mechanism which characterized in that, includes a structural support, installs rotor model, sensor, laser head and camera device on structural support, wherein:

the rotor model is used for measuring rotor wake flow;

a sensor for rotor phase locking;

a laser head for illuminating trace particles within a measurement region of the rotor wake;

the camera device is used for capturing the trace particles in the observation area to obtain a velocity field of the observation area;

the laser head and the camera device move synchronously under the action of the guide rail driving motor to acquire data of the tracer particles.

Furthermore, a driving guide rail and a driving motor are installed on the structural support, the driving guide rail is arranged along the vertical direction, the camera device and the laser head are respectively installed on the driving guide rail, and the camera device and the laser head synchronously move upwards or downwards along the vertical direction under the driving of the driving motor.

Further, the image pickup device includes two CCD cameras.

Furthermore, the sensor is installed on the fixed bolster, and is in same horizontal plane with rotor pivot index point, and the sensor locks the pivot index point.

A phase-locked measurement method for rotor wake flow (SPIV) measurement is characterized by specifically comprising the following steps of: focusing and calibrating a measurement area, starting a rotor model to rotate, generating rotor wake flow, and scattering tracer particles; determining a phase angle measured by rotor wake flow, locking a rotating shaft calibration point of the phase angle through a sensor, synchronously triggering a laser light source and a camera device each time the rotor rotates to the measured phase angle, illuminating trace particles aiming at a measurement area and carrying out data acquisition; repeatedly acquiring the locking phase for multiple times until the data condition of subsequent analysis is met; controlling a driving motor to work, enabling a camera device and a laser head to move synchronously, automatically switching a measurement area, locking a measurement phase angle, and triggering the camera device to acquire data of the measurement area; circularly performing the above contents until the data acquisition of all the measurement areas is finished, inputting parameters in the program, and starting the program to start experimental measurement; and (5) after the experiment is finished, carrying out data post-processing work.

Further, camera device includes two CCD cameras, and CCD camera and laser head are fixed mounting respectively on CCD camera branch and laser head branch, and driving motor control CCD camera branch and laser head branch remove.

The invention has the beneficial technical effects that: the invention combines the phase locking measurement and the phase averaging technology, solves the problems of high rotating speed of the rotor and limited SPIV time resolution capability, realizes the three-dimensional speed field measurement of pseudo time resolution and inhibits the higher error of transient SPIV measurement. From the previous only up to 10 rpm of the rotor can be measured up to 400 rpm. The high-rotating-speed flow field of the rotor wing can be measured, and the purpose that the measurement is close to the actual flow field is achieved. Only one calibration is needed in the experiment, so that the experiment efficiency can be improved, and the experiment difficulty can be reduced; the calibration process is simple and convenient; all stations are automatically measured according to the measurement result, the synchronous walking precision of the CCD camera and the laser head is high, and the depicting precision of the time-space evolution of the rotor wake flow is favorably improved; the phase locking measurement and phase averaging technology is combined with the SPIV technology, the problems of high rotor rotation speed and limited SPIV time resolution capability in the prior art are solved, the pseudo-time-resolved three-dimensional speed field measurement is realized, and the problem of higher error of transient SPIV measurement is restrained. The method can only analyze all the acquired data together, cannot analyze a specific phase flow field, and has inaccurate analysis result.

Drawings

Fig. 1 is a schematic topology diagram of the SPIV principle provided by the present invention.

Fig. 2 is a schematic diagram of an experimental arrangement of SPIV measurement rotor wake flow provided by the present invention.

Fig. 3 is a schematic view of the rotor wake SPIV automatic displacement mechanism provided by the present invention.

Fig. 4 is a front view of the rotor wake SPIV automatic displacement mechanism provided by the present invention.

Fig. 5 is a top view of the rotor wake SPIV automatic displacement mechanism provided by the present invention.

Fig. 6 is a side view of the rotor wake SPIV automatic displacement mechanism provided by the present invention.

Fig. 7 is a schematic view of a rotor wake SPIV measurement experiment provided by the present invention.

Detailed Description

The core idea of the invention is that in the experiment of measuring the rotor wake flow by the SPIV, a set of automatic movement measurement system and a corresponding movement measurement method are utilized to realize the one-time adjustment and calibration of two CCD cameras to focus the laser sheet, and the three-component velocity field measurement of the two-dimensional section of all stations is automatically completed, so that the efficiency of the related experiment is higher, the operation is simpler, and the precision of the flow depiction is effectively improved; meanwhile, the problems of high rotating speed of a rotor wing and limited SPIV time resolution capability are solved by combining the phase locking and SPIV measuring technologies, the pseudo-time-resolved three-dimensional speed field measurement is realized, and the problem of higher error of transient SPIV measurement is restrained. The invention will be better understood by the following description of embodiments thereof, but the applicant's specific embodiments are not intended to limit the invention to the particular embodiments shown, and any changes in the definition of parts or features and/or in the overall structure, not essential changes, are intended to define the scope of the invention.

Description of reference numerals:

drive guide rail 1, drive guide rail 2, driving motor 3, driving motor 4, structural support 5, CCD camera branch 6, laser head branch 7, CCD camera cloud platform 8, CCD camera cloud platform 9, laser head 10, support slide rail 11, support slide rail 12, support slide rail 13, support slide rail 14, CCD camera 15, CCD camera 16, rotor model 17, laser piece 18, rotor pivot 19, sensor 20

As shown in fig. 1, the principle of SPIV is that a flow field to be measured is illuminated by laser as an observation region, and a first camera and a second camera capture trace particles in the observation region at a certain angle, respectively, to obtain a velocity field of the observation region.

As shown in fig. 2, the experimental layout for measuring rotor wake by using SPIV technology ensures that the relative positions of the two CCD cameras 15, the CCD camera 16 and the laser head 10 are maintained unchanged after calibration, and when a plurality of station positions are automatically measured for the rotor wake, the CCD cameras 15, the CCD camera 16 and the laser head 10 synchronously and vertically move to switch the station position measurement.

As shown in fig. 3, the automatic movement measuring device of the present invention mainly includes a driving guide rail 1 and a driving guide rail 2, a driving motor 3 and a driving motor 4, a structural support 5, a CCD camera support rod 6, a laser head support rod 7, a CCD camera pan-tilt 8 and a CCD camera pan-tilt 9, a support slide rail 11, a support slide rail 12, a support slide rail 13 and a support slide rail 14, and the views in all directions are shown in fig. 4, 5 and 6. The CCD camera holder 8 and the CCD camera holder 9 are supporting devices for mounting and fixing the CCD camera, can adjust the horizontal and pitching angles of the camera, lock the adjusting mechanism after reaching the best working posture, and can also enlarge the monitoring range of the CCD camera or be accurately positioned by a motor to track a monitored object.

As described in fig. 7 in conjunction with fig. 2, the normal working states of the automatic phase-shift measurement apparatus and the phase-lock measurement method thereof are as follows: measure rotor model 17's wake structure, install the measurement area of the vertical rotor wake of laser head 10 illumination on laser head branch 7, CCD camera 15 is installed on CCD camera cloud platform 8, CCD camera 16 is installed on CCD camera cloud platform 9, CCD camera cloud platform 8 and CCD camera cloud platform 9 are installed on CCD camera branch 6, and CCD camera branch 6 and laser head branch 7 mutually perpendicular, sensor 20 is installed on structural support 5, the calibration point on rotor pivot 19 under the phase angle is measured to the rotor locks.

The angles of the CCD camera 15 and the CCD camera 16 relative to the measurement area are adjusted through the CCD camera holder 8 and the CCD camera holder 9 respectively, then the focal lengths of the CCD camera 15 and the CCD camera 16 are adjusted in the measurement area, and finally calibration is carried out. After calibration is completed, tracer particles are distributed in a flow field, parameters are input in a program, the program is started to start experimental measurement, a sensor 20 receives signals when a rotor rotates to a locked phase angle through the program, a laser head 10, a CCD camera 15 and a CCD camera 16 are synchronously triggered to carry out data acquisition, after the required data quantity of the measured phase angle is repeatedly acquired, the program automatically triggers a controller to synchronously control a driving motor 3 and a driving motor 4, a CCD camera support rod 6 and a laser head support rod 7 are synchronously moved to a second station along a driving guide rail 1 and a driving guide rail 2, the laser head 10 illuminates a second measurement area, then the program triggers the CCD camera 15 and the CCD camera 16 to carry out data acquisition when the rotor rotates to the locked phase angle again, and then the program sequentially starts to a third station and a fourth station until the measurement of all stations is completed.

The phase locking measurement method based on rotor wake SPIV measurement specifically comprises the following steps: experimental equipment is built and calibrated: as shown in fig. 7, the rotor model 17 is installed above the mechanism to ensure that the rotor wake is developed downwards, and according to the phase angle to be measured, a calibration point is selected at the corresponding circumferential position of the rotor rotating shaft 19, and the sensor 20 is located on the same horizontal plane as the calibration point to lock the measured phase angle. According to the field range of the laser sheet, several measurement areas are determined along the longitudinal direction, so that the rotor wake structure can be accurately depicted, and each measurement area corresponds to one measurement station. The description will be made by taking as an example the determination of 3 measurement stations a, b and c, which are three measurement positions below the rotor model 17, as shown in fig. 2, and which are sequentially spaced apart from the rotor by the movement distance L on the same plane.

First, for the measurement station a closest to the rotor model 17, the laser head 10 is illuminated by means of the laser sheet 18 (shown in fig. 2); secondly, adjusting the CCD camera holder 8 and the CCD camera holder 9 to enable the CCD camera 15 and the CCD camera 16 which are fixed on the CCD camera holder to be aligned to the measurement area a (refer to the figure 1) at a proper angle; adjusting the lenses of the CCD camera 15 and the CCD camera 16 again, and aligning the focal length to the measurement area a; and finally, carrying out calibration operation.

Rotor wake SPIV experimental measurement: starting the rotor model 17 to rotate to generate rotor wake; scattering tracer particles; sensor 20 locks the measured phase angle during rotation of rotor model 17.

In the step of experimental equipment building and calibration, focusing and calibration are already carried out on a measurement area a, and on the basis, the experimental process is determined as follows: in the rotation process of the rotor model 17, when the rotor model rotates to a measurement phase angle, the sensor 20 sends a signal to synchronously trigger the laser head 10, the CCD camera 15 and the CCD camera 16 to acquire data of a measurement area a, and the data under the enough measurement phase angle are acquired repeatedly; controlling the driving motor 3 and the driving motor 4 to work so that the CCD camera supporting rod 6 and the laser head supporting rod 7 synchronously move downwards for a distance L, driving the CCD camera 15, the CCD camera 16 and the laser head 10 to synchronously move downwards for the distance L, and automatically switching the measuring area a to the measuring area b; in the rotation process of the rotor model 17, when the rotor model rotates to a measurement phase angle, the sensor 20 sends a signal to synchronously trigger the laser head 10, the CCD camera 15 and the CCD camera 16 to acquire data of the measurement area b, and the data under the enough measurement phase angle are acquired repeatedly; controlling the driving motor 3 and the driving motor 4 to work so that the CCD camera supporting rod 6 and the laser head supporting rod 7 synchronously move downwards for a distance L, driving the CCD camera 15, the CCD camera 16 and the laser head 10 to synchronously move downwards for the distance L, and automatically switching the measuring area b to the measuring area c; in the rotation process of the rotor model 17, when the rotor model rotates to a measurement phase angle, the sensor 20 sends a signal to synchronously trigger the laser head 10, the CCD camera 15 and the CCD camera 16 to acquire data of a measurement area c, and the data under the enough measurement phase angle are acquired repeatedly; the experiment was completed. Inputting parameters in a program in the experimental process, and starting the program to start experimental measurement; and (5) finishing the experiment, starting data post-processing and the like.

In this case, the problems of the prior art need to be overcome: the rotor speed can only be when fast to carry out the analysis to all data gathered, and the calculated amount is huge, can not carry out the analysis to specific phase place flow field, and the inaccurate technical problem of analysis result. According to the invention, the same phase angle is acquired for multiple times by locking the phase angle, so that on one hand, data measurement of the specified phase angle is realized, and more accurate flow field analysis results can be obtained; on the other hand, the method breaks through the constraint that the prior art can only analyze the low-rotation-speed flow field of the rotor wing, obviously improves the accuracy of flow field analysis in the high-rotation-speed state of the rotor wing, and can analyze the flow field which is closer to the real working condition of the rotor wing.

The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features. In this patent, unless expressly stated or limited otherwise, the terms "connected," "secured," and the like are to be construed broadly, and for example, "secured" may be a fixed connection, a removable connection, or an integral part; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", "top", "bottom", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention. Furthermore, unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, as they may be fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is therefore intended that all such changes and modifications as fall within the true spirit and scope of the invention be considered as within the following claims.