Double-fixed-block molded surface continuous semi-flexible wall spraying pipe and using method

Abstract

The invention discloses a double-fixed-block profile continuous semi-flexible-wall spray pipe and a using method, and belongs to the field of wind tunnel equipment, the semi-flexible-wall spray pipe comprises an outer frame, a throat block and a downstream flexible plate, the throat block and the downstream flexible plate are connected with the outer frame through a driving rod, the downstream flexible plate is connected to the downstream end of the throat block, and the throat block is connected with the downstream end of the downstream flexible plate. The upstream end of the throat block is sequentially connected with a downstream small flexible plate, a fixed block panel and an upstream small flexible plate; a panel adjusting frame is slidably mounted on the fixed block panel, the downstream end of the panel adjusting frame is in transmission connection with the throat block through a connecting rod, the upstream end of the panel adjusting frame is rotationally connected with the outer frame, and the other end of the connecting rod is rotationally connected with the upstream end of the throat block; the upstream part of the throat block is connected with the outer frame through a driving rod, and the downstream end of the throat block is connected with the outer frame through a driving rod; the problem of contradiction between profile contour continuity and profile rigidity keeping in the existing semi-flexible wall nozzle technology can be solved, control is easy, the Mach number changing time is effectively shortened, and then the wind tunnel test efficiency is guaranteed.

Description

Technical Field

[0001] The invention relates to the field of wind tunnel equipment, in particular to a double-solid block profile continuous semi-flexible wall nozzle and a use method thereof. Background Art

[0002] In the existing wind tunnel design technology, nozzles can be divided into solid block nozzles, semi-flexible wall nozzles and full-flexible wall nozzles. The solid block nozzle has a simple structure, but its disadvantage is that only one Mach number can be obtained through each set of solid blocks, and there is a large interval between the Mach numbers, which cannot meet the needs of continuous variable Mach number tests. The semi-flexible wall nozzle is composed of a rigid moving solid block and an elastically deformed flexible plate. The contraction part of the upstream of the profile is the solid block area (generally including the solid block panel and the throat block), so a large curvature profile can be formed, shortening the length of the entire nozzle section. The disadvantage is that the overlap between the solid block panel and the throat block will bring a lap seam in the middle of the profile, which will affect the flow field of the airflow. The full-flexible wall nozzle has the advantages of a wide Mach number adjustment range and good flow field quality, but the disadvantage is that the flexible plate is long, the number of driving points is large, and the control system is complex.

[0003] Among them, the semi-flexible wall nozzle has been widely used in many types of wind tunnels because the profile curve can be controlled by a few actuators and the overall rigidity of the mechanism is good. It can achieve continuous Mach number change during the operation of the wind tunnel. In the existing semi-flexible wall nozzle, in order to overcome the above-mentioned middle lap joint problem, such as the patent with the publication number CN114894425A and the patent name of the large transonic wind tunnel semi-flexible wall nozzle, a single solid block semi-flexible wall nozzle is adopted, that is, the solid block panel is replaced by a flexible plate, and only the throat block is retained as the only solid block. Although this form ensures the continuity of the profile contour, it reduces the profile rigidity. The increased flexible plate area needs to be synchronously configured with a driving mechanism, which increases the control difficulty, and may prolong the Mach number change time and reduce the efficiency of the wind tunnel test. Summary of the invention

[0004] Therefore, in order to solve the contradiction between the continuity of the profile and the maintenance of the profile rigidity in the existing semi-flexible wall nozzle technology, the present invention provides a double-solid block profile continuous semi-flexible wall nozzle and a method of use, wherein the double-solid block profile continuous semi-flexible wall nozzle can achieve profile continuity while maintaining the profile rigidity. With the characteristics of high structural rigidity of the double solid block (throat block and solid block panel) and the linkage transmission of the double solid block, there is no need to set a drive rod in front of the throat block, which makes it simple and convenient to control the profile, effectively shortens the time of changing Mach number, and thus ensures the efficiency of wind tunnel testing.

[0005] On the one hand, the present invention provides a double-solid block profile continuous semi-flexible wall nozzle, comprising an outer frame, a throat block and a downstream flexible plate, wherein the throat block and the downstream flexible plate are respectively connected to the outer frame through a driving rod, the downstream flexible plate is connected to the downstream end of the throat block, and the upstream end of the throat block is sequentially fixedly connected with a downstream small flexible plate of a specified thickness, a solid block panel and an upstream small flexible plate, and the connection is a smooth transition (that is, the two surfaces of the connection do not overlap and are smoothly transitioned); A panel adjustment frame is slidably mounted on the inner side of the solid block panel (the side close to the outer frame), the downstream end of the panel adjustment frame is transmission-connected to the throat block through a connecting rod, the upstream end of the panel adjustment frame is rotationally connected to the outer frame, and the other end of the connecting rod is rotationally connected to the upstream end of the throat block; The upstream part of the throat block is connected to the outer frame through a first driving rod, and the downstream end of the throat block is connected to the outer frame through a second driving rod; The upstream portion of the upstream small flexible plate is overlapped with the upstream plate, and the upstream plate is a fixing member extending upstream of the nozzle into the nozzle.

[0006] Optionally, a rolling pressure wheel is installed upstream of the outer frame, and the pressure wheel presses on the upstream small flexible plate; the rotating shaft of the pressure wheel is the same as the rotating shaft connecting the panel adjustment frame and the outer frame.

[0007] Optionally, the inner side of the solid block panel is slidably connected to the panel adjustment frame via a slider assembly, the slider assembly includes a slide rail and a slider matching the slide rail, the slide rail is fixedly mounted on the panel adjustment frame, and the slider is fixedly mounted on the solid block panel.

[0008] Optionally, when the connecting rod and the first driving rod are in an initial position, an extension line of the connecting rod is perpendicular to the downstream small flexible plate, and during the movement, an approximately perpendicular relationship is maintained.

[0009] Optionally, the downstream small flexible plate is a section with the greatest curvature in the airflow channel profile curve.

[0010] Optionally, the upstream end of the downstream flexible plate is fixedly connected to the downstream end of the throat block, the downstream end of the downstream flexible plate is fixedly connected to the outer frame, and the inner side of the flexible plate (the side close to the outer frame) is connected to the outer frame through a third drive rod and a fourth drive rod.

[0011] On the other hand, the present invention provides a method for using the double-solid block profile continuous semi-flexible wall nozzle, comprising the following steps: According to the profile curve of the airflow channel, driving the third driving rod and the fourth driving rod to adjust the profile of the downstream flexible plate; The throat block is driven to rotate by the first driving rod and the second driving rod to adjust the profile of the throat block; In the process of the first driving rod driving the throat block to rotate, the rotation of the throat block pushes or pulls the downstream small flexible plate, the solid block panel and the upstream small flexible plate to move, wherein the upstream small flexible plate slides on the upstream plate under the support of the pressure wheel; When the throat block rotates, the connecting rod is driven to swing, and the swing of the connecting rod drives the panel adjustment frame to rotate, and the rotation of the panel adjustment frame drives the fixed block panel to rotate or slide; The linkage of the upstream small flexible plate, the solid block panel, the downstream small flexible plate, the throat block and the downstream flexible plate completes the change of the nozzle airflow flow channel profile curve.

[0012] The present invention has the following advantages: The double-solid-block profile continuous semi-flexible-wall nozzle of the present invention can realize the continuity of the profile contour while maintaining the profile rigidity. The rigidity of the semi-flexible-wall nozzle is maintained by virtue of the large structural rigidity of the double-solid-block (throat block and solid block panel). By adopting a connecting rod transmission between the double-solid-block (throat block and solid block panel), it is unnecessary to set a driving rod in front of the throat block, and the profile control is simple and convenient, which effectively shortens the Mach number change time, thereby ensuring the efficiency of the wind tunnel test.

[0013] Compared with the traditional semi-flexible wall nozzle, the double-solid block profile continuous semi-flexible wall nozzle adopts a downstream small flexible plate to connect the solid block panel and the throat block, avoiding the middle overlap seam caused by the overlap of the solid block panel and the throat block, which is more conducive to ensuring the flow field quality of the airflow.

[0014] At the same time, compared with the traditional semi-flexible wall nozzle, the double-solid block profile continuous semi-flexible wall nozzle has fewer control objects and simpler profile control, which shortens the Mach number change time. The reduction in control objects is accompanied by a reduction in drive rods, which reduces the overall failure rate and cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of the structure of the double-solid block profile continuous semi-flexible wall nozzle of the present invention; Figure 2 : is a schematic diagram of the structure of the double-solid block profile continuous semi-flexible wall nozzle profile assembly of the present invention (the arrow in the figure indicates the direction of wind flow); Figure 3 This is an axonometric schematic diagram of the connecting rod area of ​​the double-solid block profile continuous semi-flexible wall nozzle of the present invention; Figure 4 is a schematic diagram of the thickness design process of the downstream small flexible plate; In the figure: 1. outer frame; 2. upstream small flexible plate; 3. downstream small flexible plate; 4. downstream flexible plate; 5. pressure wheel; 6. solid block panel; 7. slider assembly; 8. panel adjustment frame; 9. connecting rod; 10. throat block; 11. first drive rod; 12. second drive rod; 13. third drive rod; 14. fourth drive rod; 15. upstream plate. DETAILED DESCRIPTION

[0016] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0017] In this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprises", or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article, or apparatus.

[0018] As described in the background technology, semi-flexible wall nozzles have been widely used in many types of wind tunnels because the profile curve can be controlled by a few actuators, the overall rigidity of the mechanism is good, and the Mach number can be continuously changed during the operation of the wind tunnel. In the existing semi-flexible wall nozzles, in order to overcome the above-mentioned middle lap joint problem, such as the invention patent with publication number CN114894425A and patent name of large transonic wind tunnel semi-flexible wall nozzle, a single solid block semi-flexible wall nozzle is adopted, that is, the solid block panel is replaced by a flexible plate, and only the throat block is retained as the only solid block. Although this form ensures the continuity of the profile contour, it reduces the profile rigidity. The increased flexible plate area needs to be synchronously configured with a driving mechanism, which increases the control difficulty, and may further prolong the Mach number change time and reduce the wind tunnel test efficiency.

[0019] Based on the above reasons, this embodiment provides a double solid block profile continuous semi-flexible wall nozzle, such as Figure 1-Figure 3 As shown, it includes an outer frame 1, a throat block 10 and a downstream flexible plate 4, wherein the downstream flexible plate 4 is connected to the downstream of the throat block 10 (the downstream or upstream is based on the direction of the wind flow in the nozzle, and the wind flow direction is as shown in FIG. Figure 2 The upstream end of the throat block 10 is fixedly connected with a downstream small flexible plate 3 of a specified thickness, a solid block panel 6 and an upstream small flexible plate 2 in sequence, and the connection is a smooth transition (that is, there is no overlap between the two surfaces at the connection, and a smooth transition is processed); the downstream small flexible plate is the section with the largest curvature in the airflow channel profile curve.

[0020] A panel adjustment frame 8 is slidably mounted on the inner side of the solid block panel 6 (the inner side refers to the side close to the outer frame), the downstream end of the panel adjustment frame 8 is transmission-connected to the throat block 10 through a connecting rod 9, one end of the connecting rod is rotationally connected to the panel adjustment frame 8 through a rotating shaft, the upstream end of the panel adjustment frame 8 is rotationally connected to the outer frame, and the other end of the connecting rod 9 is rotationally connected to the upstream end of the throat block through a rotating shaft; The upstream part of the throat block 10 is connected to the outer frame 1 through a first driving rod 11, and the downstream end of the throat block 10 is connected to the outer frame 1 through a second driving rod 12; The upstream part of the upstream small flexible plate 2 is overlapped with the upstream plate 15, and the upstream plate 15 is a fixing member extending from the upstream of the nozzle into the nozzle. The overlap is located at the front end of the nozzle and will not affect the profile inside the nozzle.

[0021] A rolling pressure wheel 5 is installed upstream of the outer frame 1 , and the pressure wheel 5 presses on the upstream small flexible plate 2 ; the rotating shaft of the pressure wheel 5 is the same as the rotating shaft connecting the panel adjustment frame 8 and the outer frame 1 .

[0022] The upstream end of the downstream flexible plate 4 is fixedly connected to the downstream end of the throat block 10, and the downstream end of the downstream flexible plate 4 is fixedly connected to the outer frame. The inner side of the flexible plate (the side close to the outer frame) is connected to the outer frame 1 through the third driving rod 13 and the fourth driving rod 14.

[0023] The above technical features can maintain the rigidity of the nozzle profile while achieving the continuity of the profile contour; the throat block and the solid block panel are used in conjunction to realize two double solid block profiles, thereby maintaining the rigidity of the profile; in order to allow the throat block and the solid block panel to be linked, the throat block and the solid block panel are connected by a connecting rod, and the power is transmitted through the swing of the connecting rod, and the position changes of the throat block and the solid block panel during linkage are adapted; and after transmission through the connecting rod, it is possible to achieve the situation that there is no need to set a driving rod upstream of the throat block, which makes it simple and convenient to control the profile, effectively shortens the Mach number change time, and thus ensures the efficiency of the wind tunnel test. In order to achieve the continuity of the profile contour of the throat block and the solid block panel, the throat block and the solid block panel are connected by a downstream small flexible plate. The downstream small flexible plate adopts a fixed connection to achieve the continuity of the profile contour. At the same time, the downstream small flexible plate is located in the section with the largest curvature in the airflow channel profile curve, and can adapt to the change of curvature. The downstream small flexible plate cooperates with the throat block and the solid block panel connected by a connecting rod to replace the traditional overlapping connection method in this section, thereby avoiding the surface discontinuity caused by traditional overlapping, and the problem that the overlapping seam will affect the flow field of the airflow.

[0024] In the above technical features, the upstream small flexible plate is fixedly connected to the solid block panel, and the upstream small flexible plate can adapt to the change of the curvature of the profile at that location, and the profile contour is continuous; in order to adapt to the movement of the upstream small flexible plate when adjusting the profile, the front part of the upstream small flexible plate is overlapped with the upstream plate of the nozzle by overlapping, and the position of the overlap will not affect the continuity of the entire profile, because the overlap is already outside the effective contour (the effective contour is the part of the profile contour that actually participates in controlling the airflow) range, and the overlap can adapt to the displacement change of the upstream small flexible plate. At the same time, the rotating pressure wheel can ensure that the upstream small flexible plate is closely fitted with the upstream plate, achieve effective overlap, and avoid the separation of the upstream small flexible plate from the upstream plate and affect the profile of the upstream end of the solid block panel.

[0025] In the above technical features, by adopting a sliding connection between the solid block panel and the panel adjustment frame, when the connecting rod drives the panel adjustment frame, the panel adjustment frame and the solid block panel can move relative to each other to achieve adjustment of the entire profile contour.

[0026] In order to realize relative movement between the panel adjustment frame and the solid block panel, in one embodiment, the inner side (the side close to the outer frame) of the solid block panel 6 is slidably connected to the panel adjustment frame 8 through a slider assembly 7, and the slider assembly 7 includes a slide rail and a slider matching the slide rail, the slide rail is fixedly installed on the panel adjustment frame, and the slider is fixedly installed on the solid block panel.

[0027] In order to improve the rigidity of the connection between the throat block and the panel adjustment frame, in one embodiment, when the connecting rod 9 and the first driving rod 11 are in the initial position of the nozzle (i.e., the design position), the connecting rod and the first driving rod are parallel to each other and the extension line is perpendicular to the downstream small flexible plate, and the intersection of the extension line and the frame is the installation position of the first driving rod; when the nozzle is in the process of changing the Mach number, the extension line of the connecting rod maintains an approximately vertical relationship with the downstream small flexible plate (absolute verticality is not required), and an angle is generated between the connecting rod and the first driving rod.

[0028] In the field of wind tunnel equipment design, the input condition for nozzle design is the airflow flow path profile curve given by the aerodynamic profession. This curve changes with the Mach number. When the curve changes with the Mach number, there is a time-varying curvature portion and a time-invariant curvature portion. The double-solid block profile continuous semi-flexible wall nozzle described in this embodiment uses the time-invariant curvature portion as the solid block profile, and the curve between the two solid block profiles is the downstream small flexible plate 3. Since the curve to which the downstream small flexible plate belongs is the section with the largest curvature in the profile curve, in order to avoid the plate from breaking, the previous double-solid block semi-flexible wall nozzles all adopt the overlap form, which results in an overlap seam in the middle of the profile. In order to overcome the problem of the overlap seam in the middle, the present invention designs a downstream small flexible plate to connect the solid block panel and the throat block. The length of the downstream small flexible plate can be obtained by extending the curve, and the thickness needs to be determined through simulation iteration. If the thickness is too large, the flexibility of the plate is poor, and there is a risk of the plate breaking, while if the thickness is too small, the rigidity of the plate is weak, and there is a risk of the plate becoming unstable. For this reason, in one embodiment, Figure 4 As shown, the thickness calculation method of the downstream small flexible plate 3 is as follows: S100. Establish a nozzle finite element model at the maximum Mach number, making the thickness of the downstream small flexible plate a variable (maximum positive bending); S200, establish the nozzle finite element model at the minimum Mach number, making the thickness of the downstream small flexible plate a variable (maximum reverse bending); S300, preset a thickness, which can be set larger; S400, input the thickness into the two models and calculate using finite element software; S500, checking the calculation results of the two models, extracting the maximum stress value of the two, and judging whether it is greater than the allowable stress of the material; S600, if the result is greater than the allowable stress, reduce the thickness and return to step S400; S700: If the result is less than or equal to the allowable stress, the current thickness is used as the optimal downstream small flexible plate thickness.

[0029] The above-mentioned technical features can determine the reasonable thickness of the downstream small flexible plate. The reasonable thickness of the downstream small flexible plate avoids the risk of plate breakage. The downstream small flexible plate, throat block, solid block panel and the throat block and solid block panel based on this thickness adopt connecting rod transmission, which can replace the traditional overlap design at this location and solve the problem of surface discontinuity caused by the overlap, affecting the flow field of the airflow.

[0030] In another embodiment, a method for using the double-solid block profile continuous semi-flexible wall nozzle is provided, comprising the following steps: According to the profile curve of the airflow channel, driving the third driving rod and the fourth driving rod to adjust the profile of the downstream flexible plate; The throat block is driven to rotate by the first driving rod and the second driving rod to adjust the profile of the throat block; In the process of the first driving rod driving the throat block to rotate, the rotation of the throat block pushes or pulls the downstream small flexible plate, the solid block panel and the upstream small flexible plate to move, wherein the upstream small flexible plate slides on the upstream plate under the support of the pressure wheel; When the throat block rotates, the connecting rod is driven to swing, and the swing of the connecting rod drives the panel adjustment frame to rotate, and the rotation of the panel adjustment frame drives the fixed block panel to rotate or slide; The linkage of the upstream small flexible plate, the solid block panel, the downstream small flexible plate, the throat block and the downstream flexible plate completes the change of the nozzle airflow flow channel profile curve.

[0031] Through the above-mentioned technical features, it is possible to control the contour of the wind tunnel simply and conveniently, effectively shorten the time for changing the Mach number, and thus ensure the efficiency of the wind tunnel test.

[0032] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A double-solid block profile continuous semi-flexible wall nozzle, comprising an outer frame, a throat block and a downstream flexible plate, wherein the throat block and the downstream flexible plate are respectively connected to the outer frame through a driving rod, and the downstream flexible plate is connected to the downstream end of the throat block, characterized in that: The upstream end of the throat block is fixedly connected in sequence with a downstream small flexible plate of a specified thickness, a solid block panel and an upstream small flexible plate; A panel adjustment frame is slidably mounted on the inner side of the solid block panel, the downstream end of the panel adjustment frame is transmission-connected to the throat block via a connecting rod, the upstream end of the panel adjustment frame is rotationally connected to the outer frame, and the other end of the connecting rod is rotationally connected to the upstream end of the throat block; The upstream part of the throat block is connected to the outer frame through a first driving rod, and the downstream end of the throat block is connected to the outer frame through a second driving rod; The upstream portion of the upstream small flexible plate is overlapped with the upstream plate, and the upstream plate is a fixing member extending upstream of the nozzle into the nozzle.

2. The double-solid block profile continuous semi-flexible wall nozzle according to claim 1, characterized in that: A rolling pressure wheel is installed upstream of the outer frame, and the pressure wheel presses on the upstream small flexible plate.

3. The double-solid block profile continuous semi-flexible wall nozzle according to claim 1, characterized in that: The inner side of the solid block panel is slidably connected to the panel adjustment frame through a slider assembly, and the slider assembly includes a slide rail and a slider matching the slide rail. The slide rail is fixedly installed on the panel adjustment frame, and the slider is fixedly installed on the solid block panel.

4. The double-solid block profile continuous semi-flexible wall nozzle according to claim 1, characterized in that: The downstream small flexible plate is a section with the greatest curvature in the profile curve of the airflow channel.

5. The double-solid block profile continuous semi-flexible wall nozzle according to claim 4, characterized in that: The thickness calculation method of the downstream small flexible plate is as follows: S100, establish the nozzle finite element model at the maximum Mach number, making the thickness of the downstream small flexible plate a variable; S200, establish the nozzle finite element model at the minimum Mach number, making the thickness of the downstream small flexible plate a variable; S300, preset a thickness; S400, input the thickness into the two models and calculate using finite element software; S500, checking the calculation results of the two models, extracting the maximum stress value of the two, and judging whether it is greater than the allowable stress of the material; S600, if the result is greater than the allowable stress, reduce the thickness and return to step S400; S700. If the result is less than or equal to the allowable stress, the current thickness is used as the thickness of the downstream small flexible plate.

6. The double-solid block profile continuous semi-flexible wall nozzle according to claim 2, characterized in that: The rotating shaft of the pressing wheel is the same as the rotating shaft connecting the panel adjustment frame and the outer frame.

7. The double-solid block profile continuous semi-flexible wall nozzle according to claim 2, characterized in that: The upstream end of the downstream flexible plate is fixedly connected to the downstream end of the throat block, the downstream end of the downstream flexible plate is fixedly connected to the outer frame, and the inner side of the flexible plate is connected to the outer frame through the third driving rod and the fourth driving rod.

8. A method for using the double-solid block profile continuous semi-flexible wall nozzle according to any one of claims 1 to 7, characterized in that: These include: According to the profile curve of the airflow channel, driving the third driving rod and the fourth driving rod to adjust the profile of the downstream flexible plate; The throat block is driven to rotate by the first driving rod and the second driving rod to adjust the profile of the throat block; In the process of the first driving rod driving the throat block to rotate, the rotation of the throat block pushes or pulls the downstream small flexible plate, the solid block panel and the upstream small flexible plate to move, wherein the upstream small flexible plate slides on the upstream plate under the support of the pressure wheel; When the throat block rotates, the connecting rod is driven to swing, and the swing of the connecting rod drives the panel adjustment frame to rotate, and the rotation of the panel adjustment frame drives the fixed block panel to rotate or slide; The linkage of the upstream small flexible plate, the solid block panel, the downstream small flexible plate, the throat block and the downstream flexible plate completes the change of the nozzle airflow flow channel profile curve.

Images