Full scale hybrid laminar flow vertical tail configuration for low speed wind tunnel

Abstract

This invention proposes a full-size hybrid laminar flow vertical tail prototype structure for low-speed wind tunnels, belonging to the technical field of special test model design for low-speed wind tunnels. The aim is to achieve a lightweight and low-cost design for the full-size hybrid laminar flow vertical tail body while ensuring stability and maneuverability. In this invention, the upper, middle, and lower sections of the vertical tail are connected sequentially. The external body of the vertical tail is covered by a vertical tail skin and a cover plate. Heating wires are laid inside the vertical tail skin on one side of the middle section. Several pressure measurement holes are arranged on the upper and lower sections of the vertical tail. An air intake chamber is installed on the middle section of the vertical tail, comprising 21 independent air intake chambers. Each independent air intake chamber has four air intake holes and one independent air intake chamber pressure measurement hole on its sidewall. Steel pipes from the upper, middle, and lower sections of the vertical tail pass through reinforcing ribs to form a grid structure, with positioning rulers on both sides of the grid. This invention achieves a lightweight and low-cost design for the vertical tail, facilitating model installation in the wind tunnel and alleviating pressure on the support system.

Description

Technical Field

[0001] This invention relates to the field of special test model design technology for low-speed wind tunnels, and in particular to a full-size hybrid laminar flow vertical tail prototype structure for a low-speed wind tunnel. Background Technology

[0002] Research on drag reduction for components such as wings and nacelles of civil aircraft has gradually matured. However, the maturity of drag reduction design methods for vertical tails varies greatly. The operational requirements of balancing stability and maneuverability for vertical tail components dictate a significant difference in design philosophy compared to wings, rendering previously accumulated design methods unusable. Therefore, developing mixed laminar flow design for vertical tails is crucial for drag reduction design of low-drag, quiet aircraft and is an important piece of the puzzle in achieving drag reduction research for civil aircraft.

[0003] Vertical tail hybrid laminar flow control technology involves controlling air intake at the leading edge of the vertical tail to suppress crossflow and attachment line transition, while simultaneously utilizing surface design to maintain stable laminar flow by taking advantage of favorable pressure distribution characteristics. For studying the effectiveness of vertical tail hybrid laminar flow control technology, wind tunnel verification tests, especially full-scale simulation verification in low-speed wind tunnels, are the most effective and direct means.

[0004] The full-size vertical tail hybrid laminar flow prototype has approached near-real-world testing conditions in the wind tunnel. An intake chamber needs to be installed inside the leading edge of the vertical tail. This is achieved by designing a microporous structure on the leading edge surface and using an intake control system to draw air into the tail surface. The intake system continuously expels the drawn-in outside air from the chamber via a compressor and transmission pipes to stabilize the internal pressure, thus providing a stable intake boundary for laminar flow control. Wind tunnel testing requires consideration of the installation of control and measurement systems, as well as a high surface finish on the vertical tail. The controllability of the microporous region, the intake air source, and the piping arrangement all pose new challenges to the full-size vertical tail structure, manufacturing process, and machining accuracy, necessitating corresponding technical research to address these issues. In conclusion, there is an urgent need to design a lightweight, low-cost device capable of achieving a full-size hybrid laminar flow vertical tail body while ensuring stability and maneuverability. Summary of the Invention

[0005] A brief overview of the invention is given below to provide a basic understanding of certain aspects of it. It should be understood that this overview is not an exhaustive summary of the invention. It is not intended to identify key or essential parts of the invention, nor is it intended to limit the scope of the invention. Its purpose is merely to present certain concepts in a simplified form as a prelude to the more detailed description that follows.

[0006] In view of this, in order to achieve a lightweight and low-cost design of a full-size hybrid laminar flow vertical tail body while ensuring stability and maneuverability, the present invention provides a prototype structure of a full-size hybrid laminar flow vertical tail for a low-speed wind tunnel.

[0007] Solution: A full-size hybrid laminar flow vertical tail prototype structure for a low-speed wind tunnel, comprising a vertical tail body and an intake chamber;

[0008] The main body of the vertical tail includes an upper section, a middle section and a lower section of the vertical tail, which are connected in sequence. The exterior of the main body of the vertical tail is covered by a vertical tail skin and a cover plate. A heating wire is laid inside the vertical tail skin on one side of the middle section of the vertical tail. Several vertical tail pressure measuring holes are arranged on the upper section and the lower section of the vertical tail.

[0009] The air intake chamber is installed on the middle section of the tail. The air intake chamber includes 21 independent air intake chambers, an outer skin of the air intake chamber, and a side plate of the air intake chamber. Each independent air intake chamber has four air intake holes and one independent air intake chamber pressure measuring hole on its side wall. The air intake chamber is fixedly connected to the tail body through the side plate of the air intake chamber. An outer skin of the air intake chamber is provided on the outside of the air intake chamber.

[0010] The upper, middle, and lower sections of the vertical tail each include a steel pipe, reinforcing ribs, and positioning rulers. The steel pipe passes through the reinforcing ribs to form a grid structure, and positioning rulers are provided on the left and right sides of the grid.

[0011] Furthermore, the outer skin of the intake chamber is made of a thin-walled titanium alloy material that can be perforated.

[0012] Furthermore, the air intake cavity is realized using a 3D printing additive manufacturing process.

[0013] Furthermore, the air intake is connected to a flexible hose via an adapter.

[0014] Furthermore, the reinforcing rib is provided with a through hole for the hose to pass through. The hose passes through the reinforcing ribs with holes in the middle section and the lower section of the tail respectively, and finally leads out through the round hole at the bottom of the lower section of the tail to connect with the control system outside the wind tunnel.

[0015] Furthermore, the steel pipe is provided with reinforcing rings at both the upper and lower ends.

[0016] The present invention has the following advantages over the prior art:

[0017] 1. The device of this invention adopts 3D printing additive manufacturing combined with welding process to realize the integrated processing of large-size and multiple air intake chambers. The outer skin of the chamber is a thin-walled titanium alloy material that can be laser-drilled for micro-holes. The air intake chamber structure takes into account the installation and arrangement of air intake interface and pipeline, effectively ensuring the test requirements of full-size vertical tail mixed laminar flow wind tunnel.

[0018] 2. The device of the present invention uses a simplified structure with internal load-bearing steel pipes welded to stiffening beams and external composite materials, which achieves lightweight and low-cost design, facilitates model installation in wind tunnel, and alleviates the pressure on the support system. Attached Figure Description

[0019] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0020] Figure 1 A schematic diagram of a full-size hybrid laminar flow vertical tail prototype for a low-speed wind tunnel.

[0021] Figure 2 This is a schematic diagram of the internal structure of the intake chamber;

[0022] Figure 3 A diagram showing the positional relationship between the outer skin of the inhalation chamber and the side plate of the inhalation chamber.

[0023] Figure 4 This is a cross-sectional view of the intake chamber;

[0024] Figure 5 This is a schematic diagram of the internal structure of the vertical tail body;

[0025] Figure 6 A schematic diagram showing the location of the heating area and pressure measurement points on the main body of the vertical tail.

[0026] Figure 7 for Figure 6 Enlarged detail image of point A.

[0027] In the diagram: 1-Upper section of vertical tail, 2-Middle section of vertical tail, 3-Cover plate, 4-Intake chamber, 5-Lower section of vertical tail, 6-Independent intake chamber, 7-Independent intake chamber pressure measuring hole, 8-Intake hole, 9-Outer skin of intake chamber, 10-Side plate of intake chamber, 11-Steel pipe, 12-Reinforcing ring, 13-Reinforcing rib, 14-Positioning ruler, 15-Heating wire, 16-Pressure measuring hole of vertical tail. Detailed Implementation

[0028] To make the technical solutions and advantages of the embodiments of the present invention clearer, the exemplary embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not an exhaustive list of all embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0029] Example 1, Reference Figure 1-7 This embodiment describes a full-size hybrid laminar flow vertical tail prototype structure for a low-speed wind tunnel, comprising a vertical tail body and an intake chamber 4.

[0030] The main body of the tail includes an upper section 1, a middle section 2 and a lower section 5. The upper section 1, the middle section 2 and the lower section 5 are connected in sequence. The main body is covered by a tail skin and a cover plate 3. A heating wire 15 is laid inside the tail skin on one side of the middle section 2. Several tail pressure measuring holes 16 are arranged on the upper section 1 and the lower section 5.

[0031] The air intake chamber 4 is installed on the middle section 2 of the tail section. The air intake chamber 4 includes 21 independent air intake chambers 6, an outer skin 9 of the air intake chamber, and a side plate 10 of the air intake chamber. Each independent air intake chamber 6 has four air intake holes 8 and one independent air intake chamber pressure measuring hole 7 on its side wall. The air intake chamber 4 is fixedly connected to the tail section through the side plate 10 of the air intake chamber. The outer skin 9 of the air intake chamber is provided on the outside of the air intake chamber 4.

[0032] The upper section 1, middle section 2, and lower section 5 of the vertical tail each include a steel pipe 11, a reinforcing rib 13, and a positioning ruler 14. The steel pipe 11 passes through the reinforcing rib 13 to form a grid structure, and positioning rulers 14 are provided on the left and right sides of the grid.

[0033] Furthermore, the outer skin 9 of the air intake chamber is made of a thin-walled titanium alloy material that can be perforated.

[0034] Furthermore, the air intake chamber 4 is manufactured using a 3D printing additive manufacturing process.

[0035] Furthermore, the air intake 8 is connected to a flexible hose via an adapter.

[0036] Furthermore, the reinforcing rib 13 is provided with a through hole for the hose to pass through. The hose passes through the reinforcing rib 13 with holes in the middle section 2 and the lower section 5 of the tail respectively, and finally leads out through the round hole at the bottom of the lower section 5 of the tail to connect with the control system outside the wind tunnel.

[0037] Furthermore, the steel pipe 11 is provided with reinforcing rings 12 at both the upper and lower ends.

[0038] Furthermore, the upper section 1, middle section 2, and lower section 5 of the tail are all provided with lifting holes, and the sections are positioned by pin holes and connected by screws.

[0039] This invention achieves integrated processing of large-size, multi-quantity air intake chambers by using 3D printing additive manufacturing combined with welding technology. The outer skin of the chamber is made of thin-walled titanium alloy material that can be laser-drilled for micro-holes. Furthermore, the air intake chamber structure takes into account the installation and layout of air intake interfaces and pipelines, effectively ensuring the testing requirements of a full-size vertical tail mixed laminar flow wind tunnel.

[0040] The simplified structure of the vertical tail body in this invention, which is achieved by welding internal load-bearing steel pipes and reinforcing beams and using composite materials on the outside, realizes lightweight and low-cost design, facilitates model installation in wind tunnel, and alleviates the pressure on the support system.

[0041] Although the invention has been described with reference to a limited number of embodiments, those skilled in the art will understand from the foregoing description that other embodiments are conceivable within the scope of the invention described herein. Furthermore, it should be noted that the language used in this specification has been chosen primarily for readability and instructional purposes, and not for the purpose of interpreting or limiting the subject matter of the invention. Therefore, many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the appended claims. The disclosure of the invention is illustrative and not restrictive, and the scope of the invention is defined by the appended claims.

Claims

1. A full-size hybrid laminar flow vertical tail prototype structure for a low-speed wind tunnel, characterized in that, Includes the main body of the vertical tail and the air intake chamber (4); The main body of the vertical tail includes an upper section (1), a middle section (2) and a lower section (5). The upper section (1), the middle section (2) and the lower section (5) are connected in sequence. The main body of the vertical tail is covered by a vertical tail skin and a cover plate (3). A heating wire (15) is laid inside the vertical tail skin on one side of the middle section (2). Several vertical tail pressure measuring holes (16) are arranged on the upper section (1) and the lower section (5). The air intake chamber (4) is installed on the middle section (2) of the vertical tail. The air intake chamber (4) includes 21 independent air intake chambers (6), an outer skin (9) of the air intake chamber, and an outer side plate (10) of the air intake chamber. Each independent air intake chamber (6) has four air intake holes (8) and an independent air intake chamber pressure measuring hole (7) on its side wall. The air intake chamber (4) is fixedly connected to the main body of the vertical tail through the outer side plate (10) of the air intake chamber. The outer skin (9) of the air intake chamber (4) is provided on the outside of the air intake chamber. The upper section (1), middle section (2) and lower section (5) of the vertical tail each include a steel pipe (11), a reinforcing rib (13) and a positioning ruler (14). The steel pipe (11) passes through the reinforcing rib (13) to form a grid structure, and positioning rulers (14) are provided on the left and right sides of the grid.

2. The low-speed wind tunnel full-size hybrid laminar flow vertical tail prototype structure according to claim 1, characterized in that, The outer skin (9) of the air intake chamber is made of thin-walled titanium alloy material that can be perforated.

3. The low-speed wind tunnel full-size hybrid laminar flow vertical tail prototype structure according to claim 2, characterized in that, The air intake cavity (4) is realized by 3D printing additive manufacturing process.

4. The low-speed wind tunnel full-size hybrid laminar flow vertical tail prototype structure according to claim 1, characterized in that, The air intake (8) is connected to a flexible hose via an adapter.

5. The low-speed wind tunnel full-size hybrid laminar flow vertical tail prototype structure according to claim 4, characterized in that... The reinforcing rib (13) is provided with a through hole for the hose to pass through. The hose passes through the reinforcing rib (13) with holes in the middle section (2) and the lower section (5) of the tail respectively, and finally leads out through the round hole at the bottom of the lower section (5) of the tail to connect with the control system outside the wind tunnel.

6. The low-speed wind tunnel full-size hybrid laminar flow vertical tail prototype structure according to claim 1, characterized in that, The steel pipe (11) is provided with reinforcing rings (12) at both the upper and lower ends.

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