Variable-angle supporting rod for presetting attack angle or sideslip angle

Abstract

The invention discloses a variable-angle supporting rod for presetting an attack angle or a sideslip angle, and belongs to the field of wind tunnel tests. The angle-variable support rod is formed by connecting a plurality of detachable support rods and at least comprises a first support rod, a second support rod and a third support rod; the first supporting rod is connected with a balance; the third supporting rod is connected with an attack angle mechanism; the second support rod is connected between the first support rod and the third support rod, so that the first support rod and the third support rod form a deflection angle meeting wind tunnel test requirements; the supporting rods are connected in a taper hole fit mode, lateral wedges are used for positioning and fastening, the front-section axis and the rear-section axis of the second supporting rod are coplanar, the deflection angle is alpha, key grooves are formed in the connecting end of the third supporting rod and the attack angle mechanism at 90-degree intervals in the circumferential direction, and deflection in the four directions of positive and negative attack angles and positive and negative sideslip angles is achieved. According to the invention, the requirement of presetting different attack angles or different sideslip angles of the model can be met only by configuring the second supporting rods with different deflection angles, the applicability is wide, and the cost is saved.

Description

Technical Field

[0001] The invention relates to the field of wind tunnel testing, in particular to a variable angle support rod for presetting an attack angle or a sideslip angle. Background Art

[0002] Wind tunnel testing involves installing an aircraft model in a wind tunnel to study air flow and its interaction with the model, thereby understanding the aerodynamic characteristics of the actual aircraft. As an important means of evaluating aircraft performance, wind tunnel testing plays a crucial role in the development of aviation and aerospace vehicles. During wind tunnel testing, the model is manipulated into various postures to measure aerodynamic parameters in each state. To accurately track and hit targets, or to evade attacks, aircraft must be able to perform high angles of attack, large sideslip maneuvers, navigate complex flow environments, and complete complex flight missions.

[0003] Early wind tunnel angle-of-attack mechanisms were simple, capable of only changing the angle of attack within a fixed range and lacking the ability to side-slip. Replacing a new wind tunnel mechanism required considering numerous factors, including the foundation, tunnel structure, and control, resulting in significant effort and a lengthy turnaround. Summary of the Invention

[0004] The technical problem solved by the present invention is: to overcome the shortcomings of the existing technology and provide a variable angle support rod for presetting the angle of attack or sideslip angle, so as to meet the test requirements of presetting different angles of attack or sideslip angles of the model and extend the test range of the wind tunnel equipment.

[0005] The technical solution of the present invention is: a variable-angle support rod for presetting the angle of attack or sideslip angle, which is composed of multiple detachable support rods, including at least a first support rod, a second support rod and a third support rod; the first support rod is used to connect to a balance, and the third support rod is used to connect to the angle of attack mechanism; the second support rod is connected between the first support rod and the third support rod, so that the first support rod and the third straight rod form a deflection angle that meets the requirements of the wind tunnel test.

[0006] Furthermore, the connection between each section of the support rod adopts a tapered hole fit; the connection side of the second support rod with the first support rod is the second support rod hole section, and the connection side with the third straight rod is the second support rod tapered section. The axes of the second support rod hole section and the second support rod tapered section are coplanar and the deflection angle is n°, where n is the deflection angle required for the test.

[0007] Furthermore, the central axis of the first support rod cone segment is collinear with the central axis of the second support rod hole segment and is perpendicular to the mating end surface, and the central axis of the second support rod cone segment is collinear with the central axis of the third support rod hole segment and is perpendicular to the mating end surface.

[0008] Furthermore, wedges are used to fasten the tapered holes between the support rod sections; wherein the wedge holes pass through the tapered section and the hole section and are parallel to the center plane; the center plane is the plane formed by the center axes of the interconnected tapered section and the hole section.

[0009] Furthermore, the wedge holes at the cone section and the hole section are of the same size and are axially offset from each other along the wedge holes, so that when the wedge is inserted, one side fits against the surface of the cone section and the other side fits against the surface of the hole section.

[0010] Furthermore, a wedge hole for removal is provided at a certain distance from the wedge hole for installation. The wedge hole for removal is used to accommodate a wedge for removal, and the distance between the two wedge holes satisfies that: when the wedge for removal is inserted, it can act on the end face of the cone section, causing the cone section to be squeezed and separated from the hole section.

[0011] Furthermore, the tapered holes between the support rod sections are fitted with keys for circumferential positioning; the key slots are perpendicular to the 90° direction of the central plane.

[0012] Furthermore, the first support rod includes an equal straight section and a connecting section; the length of the equal straight section must meet the test requirements, and the end face of the connecting section extends out of the first support rod tapered section.

[0013] Furthermore, four key slots are designed at 90° intervals in the circumferential direction on the connection side between the third support rod and the angle of attack mechanism. By connecting different key slots and the angle of attack mechanism, deflection in four directions of positive and negative angles of attack and positive and negative sideslip angles can be achieved.

[0014] Furthermore, each support rod is a hollow structure and is used for balance wiring.

[0015] The advantages of the present invention compared with the prior art are:

[0016] (1) The present invention extends the test range of wind tunnel equipment by designing a variable-angle support rod to achieve the preset angle of attack or sideslip angle, effectively meeting the needs of this type of test. Compared with the large project of changing the angle of attack mechanism, the present invention is simple and easy to implement, solving the urgent problem.

[0017] (2) The present invention cleverly divides the traditional strut shape into segments. It only needs to configure a series of second struts with different deflection angles to meet the model's preset requirements for different attack angles or different sideslip angles. Compared with the problem of customizing a strut for each test, this greatly saves time and economic costs.

[0018] (3) The present invention has a simple structure and high processing precision. It is easy to replace the second support rod during the test. The model and the first support rod are disassembled and assembled as a whole. Firstly, the installation precision of the model and the balance is guaranteed, and the continuity and comparability of the data are improved. Secondly, the traditional overall replacement of the support rod is equivalent to re-preparing the test. The present invention eliminates tedious steps, saves test time, and effectively improves test efficiency.

[0019] (4) The present invention has wide applicability. Support poles for various types of wind tunnel tests can be designed and produced in series using this method. This method can effectively solve the problem that the model needs to preset a specific angle of attack or sideslip angle, and make up for the shortcomings of the existing equipment in the walking process of the test angle of attack or sideslip angle. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is an exploded view of a support rod according to an embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram of the support rod structure according to an embodiment of the present invention;

[0022] Figure 3 This is a cross-sectional view of the support rod connection according to an embodiment of the present invention;

[0023] Figure 4 This is a cross-sectional view of the wedge hole design for connecting the support rod according to an embodiment of the present invention. DETAILED DESCRIPTION

[0024] In order to better understand the technical solution of the present invention, the specific embodiments of the present invention are described below. Parts of each structure in the drawings will be described separately, and components not shown in the drawings or not described in words are forms known to those of ordinary skill in the art.

[0025] like Figure 1 、 Figure 2 As shown, the present invention provides a variable angle support rod for presetting the angle of attack or sideslip angle, and the support rod is divided into three parts: a first support rod 1, a second support rod 2, and a third support rod 3. The first support rod 1 is used to connect with a balance, and the model is connected to the support rod through the balance. The second support rod 2 connects the first support rod 1 and the third support rod 3, and adds an angle deflection. The third support rod 3 is used to connect with the angle of attack mechanism, and the support rod is fixed on the wind tunnel mechanism.

[0026] Preferably, the first support rod 1 is provided with a sufficient length of straight sections, and then the segment positions are set to avoid the influence of the change of the support rod shape on the test.

[0027] Preferably, see Figure 2 The axis of the hole section and the cone section of the second support rod 2 are coplanar and deflected at an angle n. The machining accuracy of the deflection angle n is less than 3'.

[0028] Preferably, see Figure 2 and Figure 3 The connection structure between the second support rod 2 and the first and third support rods 1 and 3 is a tapered hole fit, keyed circumferential positioning, and wedge fastening. The central axes of the tapered section of the first support rod 1 and the hole section of the second support rod 2 are collinear and perpendicular to the mating end faces. The central axes of the tapered section of the second support rod 2 and the hole section of the third support rod 3 are collinear and perpendicular to the mating end faces.

[0029] Preferably, see Figure 3 The tapered section is radially reduced near the wedge hole to leave a gap with the hole section to prevent the wedge hole from affecting the fit of the tapered surface. The wedge hole is parallel to the plane formed by the center axis of the hole section and the tapered section, and the keyway is located at 90° to this plane.

[0030] Preferably, see Figure 4 The wedge holes in the cone and hole sections are of the same size and appropriately offset axially, ensuring that when the wedge is inserted, it interacts with the cone section's surface a and the hole section's surface b, respectively, to achieve a tightening effect. Disassembly wedge holes are set at a certain distance in the hole section, so that when the wedge is inserted, it interacts with the cone section's end surface d, squeezing the cone section and separating it from the hole section.

[0031] Preferably, see Figure 2 The third support rod 3 and the angle of attack mechanism adopt cylindrical matching and key circumferential positioning. Four key slots are designed on the third support rod 3 at 90° intervals in the circumferential direction. The third support rod 3 is connected with the angle of attack mechanism through different key slots to realize the deflection of the model in four directions of positive and negative angles of attack and positive and negative sideslip angles.

[0032] Preferably, see Figure 2 The first support rod 1, the second support rod 2, and the third support rod 3 are all hollow structures and are used for balance wiring.

[0033] Preferably, a series of second support rods 2 with different deflection angles α can be configured, which is equivalent to having a series of support rods with preset different attack angles or sideslip angles, perfectly covering the needs of this type of test.

[0034] It will be understood that the present invention is described by way of example, and it will be appreciated by those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and any embodiment that falls within the scope of the claims of this application is intended to be within the scope of protection of the present invention.

[0035] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A variable angle strut for presetting an angle of attack or sideslip, characterized in that: The device is composed of multiple detachable support rods, including at least a first support rod, a second support rod and a third support rod; the first support rod is used to connect to the balance, and the third support rod is used to connect to the angle of attack mechanism; the second support rod is connected between the first support rod and the third support rod, so that the first support rod and the third straight rod form a deflection angle that meets the requirements of the wind tunnel test.

2. The variable angle support rod for presetting the angle of attack or sideslip according to claim 1, characterized in that: The connection between each section of the support rod adopts a tapered hole fit; the second support rod is connected to the first support rod by the second support rod hole section, and the connection with the third straight rod is the second support rod tapered section. The axes of the second support rod hole section and the second support rod tapered section are coplanar and the deflection angle is n°, where n is the deflection angle required for the test.

3. The variable angle support rod for presetting the angle of attack or sideslip according to claim 2, characterized in that: The central axis of the first support rod cone section is collinear with the central axis of the second support rod hole section and is perpendicular to the matching end surface. The central axis of the second support rod cone section is collinear with the central axis of the third support rod hole section and is perpendicular to the matching end surface.

4. The variable angle support rod for presetting the angle of attack or sideslip according to claim 2, characterized in that: The tapered holes between the support rod sections are fastened with wedges, wherein the wedge holes pass through the tapered section and the hole section and are parallel to the center plane, which is the plane formed by the center axes of the interconnected tapered section and the hole section.

5. The variable angle support rod for presetting the angle of attack or sideslip according to claim 4, characterized in that: The wedge holes at the cone section and the hole section are of the same size and are offset from each other along the axial direction of the wedge holes so that when the wedge is inserted, one side fits against the surface of the cone section and the other side fits against the surface of the hole section.

6. The variable angle strut for presetting the angle of attack or sideslip according to claim 5, characterized in that: A wedge hole for removal is provided at a certain distance from the wedge hole for installation. The wedge hole for removal is used to accommodate a wedge for removal, and the distance between the two wedge holes satisfies that when the wedge for removal is inserted, it can act on the end face of the cone section, causing the cone section to be squeezed and separated from the hole section.

7. The variable angle support rod for presetting the angle of attack or sideslip according to claim 4, characterized in that: The tapered holes between the support rod sections are fitted with keys for circumferential positioning; the key slots are perpendicular to the 90° direction of the central plane.

8. The variable angle strut for presetting the angle of attack or sideslip according to claim 1, characterized in that: The first support rod includes an equal straight section and a connecting section; the length of the equal straight section must meet the test requirements, and the end face of the connecting section extends out of the conical section of the first support rod.

9. The variable angle support rod for presetting the angle of attack or sideslip according to claim 1, characterized in that: On the connection side of the third support rod and the angle of attack mechanism, four key slots are designed at 90° intervals in the circumferential direction. By connecting different key slots and the angle of attack mechanism, deflection in four directions of positive and negative angles of attack and positive and negative sideslip angles can be achieved.

10. The variable angle strut for presetting the angle of attack or sideslip according to claim 1, characterized in that: Each support rod is a hollow structure and is used for balance wiring.

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