Propeller Flow Rectification Device and Design Method for High-Power Turboprop Engine Testing

Abstract

This invention discloses a propeller flow rectification device and design method for testing high-power turboprop engines. The propeller flow rectification device includes a base, a mounting frame mounted on the base, a rectification ring for guiding and rectifying the propeller flow, and an adjustable tie rod for aligning the rectification ring. The rectification ring includes a rectification panel, a structural reinforcement on the outer wall of the rectification panel, a tie rod connecting seat on the structural reinforcement, and an outer panel on the structural reinforcement. The two ends of the adjustable tie rod are connected to the tie rod connecting seat and the mounting frame, respectively. Its ingenious structure ensures the overall flow field stability within the square test chamber. The alignment of the rectification ring can be achieved by adjusting the support length of the adjustable tie rod, eliminating the need to reinstall the engine and reducing the workload of alignment. By replacing the rectification ring, it can accommodate blades of different lengths, shortening the test cycle and improving test efficiency.

Description

Technical Field

[0001] This invention relates to the field of turboprop engine technology, and in particular, to a propeller flow rectification device for testing a high-power turboprop engine. Furthermore, this invention also relates to a design method for a propeller flow rectification device for testing a high-power turboprop engine. Background Technology

[0002] During the research and evaluation tests of high-power turboprop engines on ground test benches, the aerodynamic characteristics of the propeller flow (i.e. the airflow that does work through the propeller) are complex and the aerodynamic problems are prominent. Due to the problems of airflow vortices, disturbance backflow and flow field distortion caused by the propeller flow, it is necessary to use a propeller flow rectification system to guide and rectify the propeller flow during operation.

[0003] like Figure 1 As shown, existing high-power turboprop engine propeller flow rectification systems, due to considerations such as noise reduction, fuel efficiency, and safety, typically involve constructing an indoor square test chamber 100 on the ground test rig. This square test chamber 100 is equipped with a fixed flow rectification wall 101. The flow area of ​​the central annulus of the flow rectification wall 101 is fixed, limiting the airflow capacity of the test chamber. The flow rate and velocity of the airflow field within the test chamber are restricted. Since the propeller flow of a high-power turboprop engine can reach 1000 kg / s, the flow rectification wall 101 affects the flow area of ​​the propeller flow ejected within the square test chamber 100, reducing the airflow flow within the chamber and thus throttling the overall aerodynamic performance of the square test chamber 100. This results in overall flow field disturbance and instability within the square test chamber 100.

[0004] Secondly, due to limitations in concrete infrastructure, the flow profile of the straightening wall 101 adopts a straight or semi-circular shape, rather than being designed according to the ideal streamline of the propeller flow. This results in poor flow straightening and guidance, leading to airflow rebound and vortices near the propeller 200, and a wall effect. Some of the rebounded airflow and vortices are absorbed by the propeller 200, generating an unbalanced pressure field and tip-induced airflow velocity at the circumferential blade tip. This causes abnormal aerodynamic loads on the propeller 200 and sudden changes in engine power, potentially leading to propeller blade breakage or other accidents. Other unabsorbed propeller vortices and turbulent airflow enter the engine intake behind the propeller 200, causing engine surge, stalling, and excessive vibration, affecting normal engine operation and posing serious safety hazards to the experiment.

[0005] Furthermore, the center of the annulus of the rectifier wall 101 is completely fixed during the infrastructure construction process and cannot be adjusted vertically or horizontally according to the actual central axis of the engine installation. This places extremely high demands on the engine installation precision; even slight carelessness can cause the central axis of the propeller 200 to deviate from the center of the annulus of the rectifier wall. If a significant deviation occurs, the engine must be reinstalled and the mounting bracket position adjusted, resulting in a large workload and high safety risks. During the installation and removal of the engine and propeller 200, the confined working space often leads to the possibility of the propeller 200 colliding with the rectifier wall, resulting in low work efficiency.

[0006] Finally, the concrete fixed rectifier wall 101 has poor adaptability after its structure is finalized. When the engine propeller 200 needs to be optimized or improved or when different length blades are replaced for testing, the original concrete structure needs to be demolished and a new rectifier wall needs to be built, which increases research and development costs and extends the test cycle. Summary of the Invention

[0007] This invention provides a propeller flow rectification device and design method for high-power turboprop engine testing, in order to solve the technical problems of poor rectification effect and poor adaptability of existing propeller flow rectification systems.

[0008] According to one aspect of the present invention, a propeller flow rectification device for testing a high-power turboprop engine is provided, comprising a base, a mounting frame disposed on the base, a rectification ring for guiding and rectifying the propeller flow, and an adjustable tie rod for driving the rectification ring to perform axial alignment. The rectification ring includes a rectification panel, a structural reinforcement disposed on the outer wall of the rectification panel, a tie rod connecting seat disposed on the structural reinforcement, and an outer panel disposed on the structural reinforcement. The two ends of the adjustable tie rod are respectively connected to the tie rod connecting seat and the mounting frame.

[0009] Furthermore, the adjustable rod includes a linear telescopic mechanism and connecting seats arranged at both ends of the linear telescopic mechanism. The connecting seats are provided with spherical bearings and bolt assemblies for connecting the rod connecting seats or the mounting bracket. The bolt assemblies pass through the inner ring of the spherical bearings. The linear telescopic mechanism is used to drive at least one of the connecting seats to move along the axis of the linear telescopic mechanism.

[0010] Furthermore, the linear telescopic mechanism includes a connecting rod and screws symmetrically arranged at both ends of the connecting rod and screwed to the connecting rod. The screws are connected to the connecting seat, and the threads of the two screws screwed to the connecting rod are in opposite directions.

[0011] Furthermore, the structural reinforcement includes first reinforcing ribs spaced circumferentially along the rectifier ring and / or second reinforcing ribs spaced radially perpendicular to the rectifier ring.

[0012] Furthermore, the rectifier panel includes multiple arc segments connected sequentially along the circumference, with connecting plates arranged at both ends of each arc segment, and the connecting plates on two adjacent arc segments are connected by fasteners.

[0013] Furthermore, the connecting plate is connected to the structural reinforcement, and / or the connecting plate is connected to the structural reinforcement via a third reinforcing rib.

[0014] Furthermore, the inner diameter of the rectifier ring is greater than or equal to 5m, and the axial length of the rectifier ring is greater than or equal to 2m.

[0015] Furthermore, a walking mechanism is provided on the base.

[0016] According to another aspect of the present invention, a design method for a propeller flow rectification device is also provided, for designing the aforementioned propeller flow rectification device for high-power turboprop engine testing, comprising the following steps:

[0017] S1. Based on the streamline diagram of the propeller flow under ideal conditions and the trend of the change of the streamline vector direction of the propeller flow around the propeller disk, and combined with the changes in propeller flow velocity and pressure, the initial profile data points of the inner flow channel of the rectifier ring in the three-dimensional XYZ coordinate system are obtained in the fluid dynamics simulation software. The data points are converted into polar coordinate data and input into the software to fit the initial profile of the inner flow channel. The first part of the initial profile is a complete smooth curve, and the second part is a straight line segment.

[0018] S2. Select the boundary of the mainstream velocity region of the rectifier ring under the maximum operating state of the engine, determine the cross-sectional area of ​​the corresponding flow section of the rectifier ring, and determine the initial diameter of the corresponding flow section of the rectifier ring based on the cross-sectional area;

[0019] S3. Based on the initial profile of the inner channel and the initial diameter of the flow section of the rectifier ring, establish the inner channel sheet model of the rectifier ring in the software, establish the outer channel sheet model by offsetting the inner channel sheet model, and create the initial three-dimensional model of the rectifier ring by closing the inner channel sheet model and the outer channel sheet model with a smooth surface.

[0020] S4. Establish the initial flow field without the rectifier ring installed based on the factory structure, test equipment and propeller model of the square test chamber;

[0021] S5. Substitute the initial three-dimensional overall model of the rectifier ring into the initial flow field, simulate and analyze the mainstream velocity region of the engine under different operating conditions and flow cross sections, optimize the setting values ​​of the flow channel profile parameters in the rectifier ring, and determine the final profile of the flow channel in the rectifier ring; at the same time, optimize and adjust the cross-sectional thickness of the rectifier ring and the installation position of the three-dimensional overall model in the flow field based on the analysis results.

[0022] S6. Determine the final overall configuration of the rectifier ring.

[0023] Furthermore, in step S3, the specific steps for offsetting the inner flow channel sheet model to establish the outer flow channel sheet model are as follows: extend the inner flow channel sheet model radially outward by 50mm to establish the outer flow channel sheet model.

[0024] The present invention has the following beneficial effects:

[0025] The propeller flow rectification device for high-power turboprop engine testing of this invention has a base installed inside a square test chamber. The rectification ring is supported by a mounting frame, which is fixed to the base. There is no wall between the rectification ring and the square test chamber for flow throttling, which does not affect the flow of propeller-induced airflow within the square test chamber and ensures the overall flow field stability within the square test chamber. The complete circular rectification ring improves the rectification and guidance effect of the propeller flow, reduces airflow rebound and airflow vortices near the propeller, and the outer panel can cover the structural reinforcements on the outer wall of the rectification panel to prevent the propeller flow from forming airflow vortices at the structural reinforcements, ensuring the stable operation of the turboprop engine. The rectification ring and the mounting frame are connected by multiple adjustable rods. The axis of the rectification ring can be aligned by adjusting the support length of the adjustable rods. The structure is ingenious and easy to operate. It does not require reinstalling the engine, which reduces the amount of alignment work and improves test efficiency. When the propeller needs to be optimized or the blades of different lengths are replaced, only the rectification ring that matches the engine propeller needs to be replaced, which can shorten the test cycle.

[0026] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0027] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0028] Figure 1 This is a schematic diagram of an existing propeller rectification system;

[0029] Figure 2 This is a schematic diagram of the propeller flow rectification device for testing a high-power turboprop engine according to a preferred embodiment of the present invention.

[0030] Figure 3 This is a schematic diagram of the rectifier ring structure according to a preferred embodiment of the present invention;

[0031] Figure 4 This is a schematic diagram of the arc segment of a preferred embodiment of the present invention;

[0032] Figure 5 This is a schematic diagram of the outer panel structure of a preferred embodiment of the present invention;

[0033] Figure 6 This is a schematic diagram of the adjustable pull rod according to a preferred embodiment of the present invention;

[0034] Figure 7 This is a flowchart illustrating the design method of the propeller flow rectification device according to a preferred embodiment of the present invention.

[0035] Figure 8 This is a schematic diagram of the initial profile of the flow channel inside the rectifier ring according to a preferred embodiment of the present invention;

[0036] Figure 9 This is an initial flow field diagram of a preferred embodiment of the present invention without the rectifier installed;

[0037] Figure 10 This is an iterative optimization diagram of the inner profile of the rectifier panel according to a preferred embodiment of the present invention;

[0038] Figure 11 This is an iterative optimization diagram of the area of ​​the rectifier ring flow section according to a preferred embodiment of the present invention.

[0039] Legend:

[0040] 100. Square test chamber; 101. Rectifier wall; 200. Propeller; 1. Base; 2. Mounting bracket; 3. Rectifier ring; 31. Rectifier panel; 311. Arc segment; 312. Connecting plate; 313. Third reinforcing rib; 32. Structural reinforcement; 321. First reinforcing rib; 322. Second reinforcing rib; 33. Tie rod connecting seat; 34. Outer panel; 4. Adjustable tie rod; 41. Linear telescopic mechanism; 411. Connecting rod; 412. Screw; 42. Connecting seat; 43. Spherical bearing; 44. Bolt assembly. Detailed Implementation

[0041] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0042] Please refer to the following: Figures 2 to 6 The propeller flow rectification device for the high-power turboprop engine test in this embodiment includes a base 1, a mounting frame 2 arranged on the base 1, a rectification ring 3 for guiding and rectifying the propeller flow, and an adjustable tie rod 4 for driving the rectification ring 3 to perform axis alignment. The rectification ring 3 includes a rectification panel 31, a structural reinforcement 32 arranged on the outer wall of the rectification panel 31, a tie rod connecting seat 33 arranged on the structural reinforcement 32, and an outer panel 34 arranged on the structural reinforcement 32. The two ends of the adjustable tie rod 4 are respectively connected to the tie rod connecting seat 33 and the mounting frame 2.

[0043] In this embodiment, the propeller flow rectification device for the high-power turboprop engine test has a base 1 installed inside a square test chamber 100. The rectification ring 3 is supported by a mounting bracket 2, which is fixed to the base 1. There is no wall between the rectification ring 3 and the square test chamber 100 for flow throttling, so it does not affect the flow of the propeller flow ejected within the square test chamber 100, ensuring the overall flow field stability within the square test chamber 100. The complete circular rectification ring 3 can improve the rectification and guidance effect of the propeller flow, reduce airflow rebound and airflow vortices near the propeller 200, and the outer panel 34 can cover the rectification surface. The structural reinforcement 32 on the outer wall of plate 31 prevents the propeller flow from forming airflow vortices at the reinforcement 32, ensuring stable operation of the turboprop engine. The rectifier ring 3 is connected to the mounting frame 2 by multiple adjustable rods 4. The axis of the rectifier ring 3 can be aligned by adjusting the support length of the adjustable rods 4. The structure is ingenious and easy to operate, eliminating the need to reinstall the engine, reducing the workload of alignment and improving test efficiency. When the propeller 200 needs to be optimized or the blades of different lengths are replaced, only the rectifier ring 3 that matches the engine propeller needs to be replaced, which can shorten the test cycle. Optionally, the base 1 is detachably connected to the ground of the square test chamber 100. When the square test chamber 100 is not being used for testing, the entire propeller flow rectifier device can be moved to one end of the square test chamber 100, providing sufficient space for personnel to install and remove the propeller.

[0044] like Figure 3 and Figure 6As shown, in this embodiment, the adjustable pull rod 4 includes a linear telescopic mechanism 41 and connecting seats 42 arranged at both ends of the linear telescopic mechanism 41. The connecting seats 42 are provided with spherical bearings 43 and bolt assemblies 44 for connecting the pull rod connecting seat 33 or the mounting bracket 2. The bolt assemblies 44 pass through the inner ring of the spherical bearings 43. The linear telescopic mechanism 41 drives at least one connecting seat 42 to move along the axis of the linear telescopic mechanism 41. The connecting seat 42 at the first end of the linear telescopic mechanism 41 is connected to the mounting bracket 2 via the bolt assemblies 44. The connecting seat 42 at the second end of the linear telescopic mechanism 41 is connected to the pull rod connecting seat 33 on the rectifier ring 3. The bolt assemblies 44 and the connecting seats 42 are movably connected via the spherical bearings 43. When the linear telescopic mechanism 41 extends or retracts, the adjustable pull rod 4 can be adjusted. The angle of the adjustable rod 4 relative to the rectifier ring 3 is adjusted by adjusting the adjustable rod 4 at a specific position to offset the rectifier ring 3 in a predetermined direction. When the central axis of the rectifier ring 3 does not coincide with the central axis of the engine, the laser beam is first set along the rotation axis of the engine propeller 200 as the base axis. Then, two diameter ropes are installed at the front opening of the rectifier ring 3, and the intersection of the ropes is the center of the front opening. Two diameter ropes are also installed at the rear opening of the rectifier ring 3, and the intersection of the ropes is the center of the rear opening. The central axis of the rectifier ring 3 is marked by connecting the centers of the front and rear openings with ropes. Then, the adjustable rod 4 is adjusted so that the central axis of the rectifier ring 3 coincides with the laser beam, thus achieving concentricity between the central axis of the rectifier ring 3 and the central axis of the engine. Optionally, the linear telescopic mechanism 41 is a gear and rack mechanism driven by a hydraulic cylinder, air cylinder, or motor. The extension and retraction of the corresponding linear telescopic mechanism 41 is controlled individually by the controller, which has a high degree of automation, reduces the workload of alignment, and improves the efficiency of alignment. Optionally, the surface roughness of the rectifier panel 31 is less than Ra0.8, which can prevent the propeller flow from forming airflow vortices near the rectifier panel 31. Optionally, a protective layer is provided on the rectifier panel 31. Since the air in the high-power turboprop engine test chamber is mixed with evaporated fuel, lubricating oil, and water vapor, the environmental conditions are harsh, and rectifier panels made of ordinary materials are prone to rust and corrosion. The protective layer can prevent the rectifier panel 31 from rusting and being corroded, thereby extending the service life of the rectifier panel 31.

[0045] like Figure 3 and Figure 6As shown, in this embodiment, the linear telescopic mechanism 41 includes a connecting rod 411 and screws 412 symmetrically arranged at both ends of the connecting rod 411 and screwed to the connecting rod 411. The screws 412 are connected to the connecting seats 42, and the threads of the two screws 412 screwed to the connecting rod 411 are in opposite directions. When the operator rotates the connecting rod 411, it can drive the connecting seats 42 at both ends to extend and retract simultaneously, thereby realizing the self-aligning operation of the rectifier ring 3 axis. Its structure is simple, easy to operate, and low in cost. Optionally, an anti-slip structure is provided on the outer wall of the connecting rod 411 to facilitate the operator's rotation of the connecting rod 411. Optionally, the anti-slip structure is a continuous concave-convex linear structure or an array of protruding points.

[0046] like Figure 4 As shown, in this embodiment, the structural reinforcement 32 includes a first reinforcing rib 321 arranged circumferentially along the rectifier ring 3 and a second reinforcing rib 322 arranged radially perpendicular to the rectifier ring 3. Multiple first reinforcing ribs 321 are spaced apart axially along the rectifier ring 3, and multiple second reinforcing ribs 322 are spaced apart circumferentially along the rectifier ring 3. This enhances the rigidity of the rectifier ring 3, prevents deformation, and thus ensures the rectifier ring 3's guiding and rectifying effect on the propeller flow. Optionally, the first reinforcing ribs 321 and the second reinforcing ribs 322 are connected in a grid structure.

[0047] like Figure 4 As shown, in this embodiment, the rectifier panel 31 includes multiple arc segments 311 connected sequentially along the circumference. Connecting plates 312 are provided at both ends of each arc segment 311, and the connecting plates 312 on adjacent arc segments 311 are connected by fasteners. The rectifier ring 3 is an extra-large, complex three-dimensional surface with high dimensional accuracy requirements. Under existing manufacturing technology, it is difficult to process and form it as a whole. Therefore, dividing the rectifier panel 31 into multiple equal parts along the circumference at angles, stamping them, and then assembling them can significantly reduce processing difficulty and ensure the dimensional accuracy of the rectifier panel 31. Optionally, the fasteners are screws, bolt-nut assemblies, or rivets.

[0048] like Figure 4 As shown, in this embodiment, the connecting plate 312 is connected to the structural reinforcement 32, and the connecting plate 312 is connected to the structural reinforcement 32 through the third reinforcing rib 313 to ensure the connection strength of the two adjacent arc segments 311.

[0049] like Figure 5 As shown, in this embodiment, the inner diameter D of the rectifier ring 3 is greater than or equal to 5m, and the axial length L of the rectifier ring 3 is greater than or equal to 2m, so as to be suitable for high-power turboprop engine testing; the thickness W of the rectifier ring 3 is 50mm, which not only does not affect the flow area of ​​the propeller jet airflow in the square test chamber 100, but also reduces the weight of the rectifier ring 3. On the one hand, it can reduce the load on the adjustable tie rod 4, and on the other hand, it can reduce the difficulty of replacing the rectifier ring 3.

[0050] In this embodiment, a walking mechanism is provided on the base 1 to facilitate the movement of the entire propeller rectifier device within the square test chamber 100 by personnel. Optionally, the walking mechanism is a roller mounted on the base 1, and the entire propeller rectifier device is pushed by the personnel. Optionally, the walking mechanism is a motor-driven railcar, with the base 1 mounted on the railcar. A track is laid on the floor of the square test chamber 100, and the railcar is controlled by a controller to move along the track. This method has a high degree of automation, reduces the labor intensity of moving the entire propeller rectifier device, and ensures that the axis of the rectifier ring 3 does not deviate when the entire propeller rectifier device is moved.

[0051] like Figure 7 As shown, a design method for a propeller flow rectification device, used to design the propeller flow rectification device for the above-mentioned high-power turboprop engine test, includes the following steps:

[0052] S1. Based on the streamline diagram of the propeller flow under ideal conditions and the trend of the streamline vector direction change of the propeller flow around the propeller disk, combined with the changes in propeller flow velocity and pressure, the initial profile data points of the inner flow channel of the rectifying ring 3 in the three-dimensional XYZ coordinate system are obtained in the fluid dynamics simulation software. The data points are converted into polar coordinate data and input into the CAD software to fit the initial profile of the inner flow channel of the rectifying ring 3. The first part of the initial profile is a complete smooth curve, and the second part is a straight line segment. The schematic diagram of the initial profile is shown below. Figure 8 As shown:

[0053] The smooth curve of the initial profile segment is fitted iteratively, and the formula is as follows:

[0054] ;

[0055] in: Polar radius, The radius of the propeller is 200. This represents the difference between the boundary of the mainstream velocity region of the propeller flow and the 200mm tip velocity of the propeller blade when the engine is at idle speed on the ground. θ Polar angle, The values ​​represent the influence of different engine operating conditions on the mainstream propeller velocity region. The value represents the influence of propeller 200 on the flow field when it rotates relative to rectifier ring 3.

[0056] The distance from the straight section of the initial profile to the central axis of rectifier ring 3 The initial value of the length L of the straight line segment is ( The final value needs to be determined after optimization based on flow field simulation analysis;

[0057] S2. Select the boundary of the mainstream velocity region of the rectifier ring 3 under the maximum operating state of the engine, determine the cross-sectional area of ​​the corresponding flow section of the rectifier ring 3, and determine the initial diameter of the corresponding flow section of the rectifier ring 3 based on the cross-sectional area;

[0058] S3. Based on the initial profile of the inner flow channel and the initial diameter of the flow section of the rectifier ring 3, establish the inner flow channel sheet model (rectifier panel 31) of the rectifier ring 3 in CAD software, establish the outer flow channel sheet model (outer panel 34) by offsetting the inner flow channel sheet model, and create the initial three-dimensional model of the rectifier ring 3 by closing the inner flow channel sheet model and the outer flow channel sheet model with a smooth curved surface;

[0059] S4, such as Figure 9 As shown, the initial flow field without the rectifier ring 3 is established based on the factory structure of the square test chamber 100, the test equipment, and the propeller model;

[0060] S5, such as Figure 10 and Figure 11 As shown, the initial three-dimensional overall model of the rectifier ring 3 is substituted into the initial flow field to simulate and analyze the mainstream velocity region of the engine under different operating conditions and flow cross sections. The set values ​​of the flow channel profile parameters inside the rectifier ring 3 are optimized to determine the final profile of the flow channel inside the rectifier ring 3. At the same time, the cross-sectional thickness of the rectifier ring and the installation position of the three-dimensional overall model in the flow field are optimized and adjusted based on the analysis results.

[0061] S6. Determine the final overall configuration of rectifier ring 3.

[0062] The design method of the propeller flow rectification device in this embodiment is based on fluid dynamics simulation analysis. According to the streamline diagram of the propeller flow under ideal conditions (without a plant or test equipment) and the trend of the streamline vector direction change of the propeller flow around the propeller disk, and combined with the changes in propeller velocity and pressure, the initial profile of the inner flow channel of the rectification ring 3 is fitted to ensure that the rectification ring 3 has good flow guiding effect. The area of ​​the inner cross-section of the rectification ring 3 is determined by selecting the transition range between laminar and turbulent flow under different flow cross sections to ensure that the rectification ring 3 has good rectification effect. Due to the influence of the test plant structure and test equipment, the flow is affected by the internal flow conditions of the test plant. Turbulent flow fields, multiple vortices near the propeller, and backflow can seriously harm the experiment. Based on the structure of the test workshop, the test equipment, and the propeller model, an initial flow field without the rectifier was established. Based on the initial flow field boundary conditions, the mainstream velocity region under different engine operating conditions was simulated and analyzed. The parameter settings of the inner flow channel of the rectifier ring 3 were optimized, and the final profile of the inner flow channel of the rectifier ring 3 was determined. At the same time, the cross-sectional thickness of the rectifier ring 3 and the installation position of the three-dimensional overall model in the flow field were optimized and adjusted. Finally, the overall configuration of the rectifier ring 3 was determined to be a complex three-dimensional surface with a converging horn shape.

[0063] In this embodiment, the specific steps in step S3 of offsetting the inner flow channel sheet model to establish the outer flow channel sheet model are as follows: the inner flow channel sheet model is extended radially outward by 50mm to establish the outer flow channel sheet model; so that the thickness W of the rectifier ring 3 is only 50mm (e.g., Figure 5 As shown, it not only does not affect the flow area of ​​the propeller jet airflow in the square test chamber 100, but also reduces the weight of the rectifier ring 3. On the one hand, it can reduce the load on the adjustable tie rod 4, and on the other hand, it can reduce the difficulty of replacing the rectifier ring 3.

[0064] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A design method for a propeller flow rectification device, characterized in that, The propeller flow rectification device includes a base (1), a mounting frame (2) mounted on the base (1), a rectification ring (3) for guiding and rectifying the propeller flow, and an adjustable tie rod (4) for driving the rectification ring (3) to perform axis alignment. The rectification ring (3) includes a rectification panel (31), a structural reinforcement (32) mounted on the outer wall of the rectification panel (31), a tie rod connecting seat (33) mounted on the structural reinforcement (32), and an outer panel (34) mounted on the structural reinforcement (32). The two ends of the adjustable tie rod (4) are respectively connected to the tie rod connecting seat (33) and the mounting frame (2). The design method of the propeller flow rectification device includes the following steps: S1. Based on the streamline diagram of the propeller flow under ideal conditions and the trend of the change of the streamline vector direction of the propeller flow around the propeller disk, and combined with the changes in the propeller flow velocity and pressure, the initial profile data points of the inner flow channel of the rectifier ring (3) in the three-dimensional XYZ coordinate system are obtained in the fluid dynamics simulation software. The data points are converted into polar coordinate data and input into the fluid dynamics simulation software to fit the initial profile of the inner flow channel. S2. Select the boundary of the mainstream velocity region of the rectifier ring (3) under the flow section of the engine at the maximum working state, determine the cross-sectional area of ​​the rectifier ring (3) under the corresponding flow section, and determine the initial diameter of the flow section of the rectifier ring (3) based on the cross-sectional area; S3. Based on the initial profile of the inner channel and the initial diameter of the flow section of the rectifier ring (3), the inner channel sheet model of the rectifier ring (3) is established in the software. The outer channel sheet model is established by offsetting the inner channel sheet model. The initial three-dimensional model of the rectifier ring (3) is created by closing the inner channel sheet model and the outer channel sheet model with a smooth surface. S4. Based on the factory structure, test equipment and propeller model of the square test chamber (100), establish the initial flow field without the rectifier ring (3) installed; S5. Substitute the initial three-dimensional overall model of the rectifier ring (3) into the initial flow field, simulate and analyze the mainstream velocity region of the engine under different working conditions and flow cross sections, optimize the set values ​​of the flow channel profile parameters in the rectifier ring (3), and determine the final profile of the flow channel in the rectifier ring (3); at the same time, optimize and adjust the cross section thickness of the rectifier ring (3) and the installation position of the three-dimensional overall model in the flow field according to the analysis results. S6. Determine the final overall configuration of the rectifier ring (3).

2. The design method of the propeller flow rectification device according to claim 1, characterized in that, The adjustable rod (4) includes a linear telescopic mechanism (41) and connecting seats (42) arranged at both ends of the linear telescopic mechanism (41). The connecting seats (42) are provided with spherical bearings (43) and bolt assemblies (44) for connecting the rod connecting seat (33) or the mounting bracket (2). The bolt assemblies (44) pass through the inner ring of the spherical bearings (43). The linear telescopic mechanism (41) is used to drive at least one of the connecting seats (42) to move along the axis of the linear telescopic mechanism (41).

3. The design method of the propeller flow rectification device according to claim 2, characterized in that, The linear telescopic mechanism (41) includes a connecting rod (411) and screws (412) symmetrically arranged at both ends of the connecting rod (411) and screwed to the connecting rod (411). The screws (412) are connected to the connecting seat (42), and the threads of the two screws (412) screwed to the connecting rod (411) are opposite in direction.

4. The design method of the propeller flow rectification device according to any one of claims 1 to 3, characterized in that, The structural reinforcement (32) includes a first reinforcing rib (321) arranged circumferentially along the rectifier ring (3) and / or a second reinforcing rib (322) arranged radially perpendicular to the rectifier ring (3).

5. The design method of the propeller flow rectification device according to any one of claims 1 to 3, characterized in that, The rectifier panel (31) includes a plurality of arc segments (311) connected in sequence along the circumference. Connecting plates (312) are provided at both ends of the arc segments (311), and the connecting plates (312) on two adjacent arc segments (311) are connected by fasteners.

6. The design method of the propeller flow rectification device according to claim 5, characterized in that, The connecting plate (312) is connected to the structural reinforcement (32), and / or the connecting plate (312) is connected to the structural reinforcement (32) through a third reinforcing rib (313).

7. The design method of the propeller flow rectification device according to claim 1, characterized in that, The inner diameter of the rectifier ring (3) is greater than or equal to 5m, and the axial length of the rectifier ring (3) is greater than or equal to 2m.

8. The design method of the propeller flow rectification device according to claim 1, characterized in that, The base (1) is equipped with a walking mechanism.

9. The design method of the propeller flow rectification device according to claim 1, characterized in that, In step S3, the specific steps for offsetting the inner flow channel sheet model to establish the outer flow channel sheet model are as follows: extend the inner flow channel sheet model radially outward by 50mm to establish the outer flow channel sheet model.

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