Variable camber tail for fsae race car

Abstract

This invention discloses a variable cross-section tail wing suitable for FSAE racing cars, comprising a variable cross-section wing assembly, an upper sparsity wing, a first lower sparsity wing, a second lower sparsity wing, and endplates. The variable cross-section wing assembly consists of a main wing, a first flap, and a second flap; all three wings are variable cross-section wings. The variable cross-section wing is a small, continuous section raised at mid-span. The main wing, the first flap, and the second flap are sequentially mounted between the two endplates, roughly diagonally distributed, with the second flap featuring a grunt flap. The upper sparsity wing is mounted on the corner of the endplate, while the first and second lower sparsity wings are located near the bottom of the endplate. There are two endplates, symmetrically mounted on both sides, each featuring louvers, an outer edge flange, a leading edge notch, a trailing edge notch, and guide strips. The variable cross-section wing can reduce the turbulence caused by the headrest and minimize airflow slippage in the spanwise direction, resulting in a more uniform pressure distribution on the wing surface. The louver structure also reduces drag.

Description

Technical Field

[0001] This invention relates to the field of aerodynamics, and more particularly to a variable cross-section tail wing suitable for FSAE racing cars. Background Technology

[0002] In recent years, with the rapid development of the Formula Student China competition in China, universities have begun to devote more energy to aerodynamics research. When a race car moves relative to the air, the air generates aerodynamic forces and torques on the car, thus aerodynamics has a significant impact on the car's power performance and handling. The rear wing contributes the most, providing 35-45% of the negative lift.

[0003] Therefore, it is necessary to design a variable cross-section tail wing suitable for FSAE racing cars. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a variable cross-section tail wing suitable for FSAE racing cars.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0006] A variable cross-section tail wing suitable for FSAE racing cars includes endplates arranged opposite each other on both sides, and a variable cross-section wing assembly arranged between the two endplates. The variable cross-section wing assembly includes a main wing, a first flap, and a second flap arranged sequentially from the lower front to the upper rear of the endplates. The middle sections of the main wing, the first flap, and the second flap are all low angle-of-attack sections, and the two ends connected to the endplates are high angle-of-attack sections. The low angle-of-attack sections and the high angle-of-attack sections are connected by a Bézier curve model. The horizontal and vertical distances from the trailing edge of the main wing to the leading edge of the first flap are consistent, as are the horizontal and vertical distances from the trailing edge of the first flap to the leading edge of the second flap.

[0007] Furthermore, a Gurney flap is provided at the trailing edge of the second flap to increase the curvature of the airfoil's trailing edge, causing the wake airflow to deflect upwards. This can reduce airflow separation on the airfoil surface before stall occurs, and increase the upward momentum of the airflow near the trailing edge of the airfoil, thereby enhancing the airfoil surface's resistance to adverse pressure gradients.

[0008] Furthermore, it also includes an upper beam wing disposed above the main wing. The two ends of the upper beam wing are connected to the end plate. The upper beam wing is an irregularly shaped winglet, with its central chord length being half the chord lengths of the two sides, used to rectify the airflow brought by the main ring of the vehicle body.

[0009] Furthermore, a first notch is provided on the end plate near the trailing edge of the upper beam wing to guide airflow.

[0010] Furthermore, it also includes a first lower beam wing and a second lower beam wing disposed between the end plates. The first lower beam wing and the second lower beam wing are arranged sequentially from front to back behind the end plates to manage the upward airflow brought by the diffuser 17 and prevent the airflow from affecting the low-pressure area in the middle of the variable cross-section airfoil group.

[0011] Furthermore, the end plate is provided with louvers, and the blades of the louvers adopt a wing structure, which reduces drag and provides negative lift for the airflow as it passes through the louvers.

[0012] Furthermore, a second notch is provided at the top of the rear edge of the end plate to guide the airflow from the louvers.

[0013] Furthermore, a guide strip is provided on the outer side of the end plate to guide the airflow on the end plate in conjunction with the louvers, thereby reducing the generation of eddies.

[0014] Furthermore, the outer edge of the end plate is provided with a flange to enhance the negative lift and the rigidity of the end plate.

[0015] Furthermore, a third notch is provided below the leading edge of the end plate.

[0016] Compared with the prior art, the beneficial effects of the present invention are:

[0017] 1. The variable cross-section tail wing of this vehicle features a small section raised in the middle of the wingspan. The angle of attack of the middle section is small, reducing the area of ​​the main wing in the headrest projection area and minimizing the impact of turbulence caused by the headrest on the aerodynamic performance of the tail wing. The larger angle of attack of the two sides adapts to the updraft caused by the front wing. The connection between the two parts is modeled using Bezier curves to make the transition smoother. The flaps are also variable cross-section wings, ensuring that the horizontal and vertical distances from the trailing edge of the front wing to the leading edge of the rear wing remain consistent. Compared to ordinary variable cross-section wings, the variable cross-section wing assembly described in this invention has a smaller area of ​​the main wing in the headrest projection area because the trailing edge of the main wing is also raised. Furthermore, the raised section is only a small area in the middle, which facilitates further optimization by changing the raised length and interwing clearance to find a relatively better raised length and interwing clearance.

[0018] 2. The upper beam wing, first lower beam wing, and second lower beam wing of this invention further enhance negative lift, compensating for the loss of overall negative lift caused by the pressure relief of the louvers. The upper beam wing also rectifyes the airflow brought by the main ring of the vehicle body frame. Since the upper beam wing mainly manages the turbulent flow in the middle, the chords on both sides are designed to be larger so that the parts that do not need to manage the turbulent flow of the main ring can generate greater downforce. Since the airflow will rise after passing through the diffuser, the first lower beam wing and the second lower beam wing are installed below and behind the end plate to manage the rising airflow brought by the diffuser and prevent it from affecting the low-pressure area in the middle of the variable cross-section airfoil group.

[0019] 3. The present invention has a louver structure at the end plate, which connects the inner and outer sides of the end plate. The end plate has a trailing edge notch. With the louver, the airflow from the louver groove will flow into the air below the blade through the trailing edge notch and be released with the tail vortex, which achieves a good drag reduction effect. In addition, the louver blades are composed of small blades, so that when the airflow passes through the louver, it will also provide a certain negative lift, reducing the loss of overall negative lift caused by the depressurization of the louver.

[0020] 4. The end plate of this invention has guide strips, which, together with louvers, guide the airflow on the end plate and reduce the generation of eddies. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present invention;

[0022] Figure 2 This is a front view of an embodiment of the present invention;

[0023] Figure 3 This is a right view of an embodiment of the present invention;

[0024] Figure 4 This is a side sectional view of an embodiment of the present invention;

[0025] Figure 5 This is a schematic diagram of the variable cross-section airfoil structure according to an embodiment of the present invention;

[0026] Figure 6 This is a schematic diagram of the present invention assembled in a vehicle according to an embodiment;

[0027] Wherein: 1-Variable cross-section airfoil group; 2-Main wing; 3-First flap; 4-Second flap; 5-Upper beam wing; 6-First lower beam wing; 7-Second lower beam wing; 8-End plate; 9-Louvre; 10-Guide strip; 11-Flange; 12-Gurney flap; 13-First notch; 14-Second notch; 15-Third notch; 16-Front wing; 17-Diffuser; 18-Main body ring; 19-Headrest. Detailed Implementation

[0028] To enhance understanding of the present invention, we will now describe it in further detail with reference to the accompanying drawings. These embodiments are for illustrative purposes only and do not constitute a limitation on the scope of protection of the present invention.

[0029] Figure 1-6 A variable cross-section tail wing suitable for FSAE racing cars is shown, including a variable cross-section wing assembly 1, an upper spar wing 5, a first lower spar wing 6, and a second lower spar wing 7 disposed between two end plates 8.

[0030] like Figure 5As shown, the variable cross-section airfoil group 1 consists of a main wing 2, a first flap 3, and a second flap 4. The main wing 2, the first flap 3, and the second flap 4 are installed sequentially between the two end plates 8, and are distributed roughly diagonally from the lower front to the upper rear of the end plates 8. All the winglets in the variable cross-section wing group 1 are variable cross-section wings. The middle part has a small angle of attack, which reduces the area of ​​the main wing in the projection area of ​​the headrest 19 and minimizes the impact of the turbulence caused by the headrest 19 on the aerodynamic performance of the tail wing. The two sides have a large angle of attack to adapt to the updraft caused by the canard 16. The connection between the small angle of attack section and the large angle of attack section is modeled and connected using Bézier curves. The first flap 3 and the second flap 4 are also variable cross-section wings, so that the horizontal and vertical distances from the trailing edge of the main wing 2 to the leading edge of the first flap 3 are consistent, and the horizontal and vertical distances from the trailing edge of the first flap 3 to the leading edge of the second flap 4 are also consistent. Compared with ordinary variable cross-section wings, this variable cross-section wing group 1 has a smaller area of ​​the main wing 2 in the projection area of ​​the headrest 19 because the trailing edge of the main wing 2 is also raised. Moreover, only a small area in the middle is raised, which makes it easier to further optimize by changing the raised length and the interwing clearance, and find a relatively better raised length and interwing clearance.

[0031] The second flap 4 is equipped with a Gurney flap 12 at its trailing edge, which is used to increase the curvature of the airfoil trailing edge and deflect the wake airflow upward. This can reduce airflow separation on the airfoil surface before stall occurs, and increase the upward momentum of the airflow near the trailing edge of the airfoil, thereby enhancing the airfoil surface's resistance to adverse pressure gradient.

[0032] The upper wing 5 is an irregularly shaped airfoil installed above the main wing 2. The middle section of the airfoil has a shorter chord length of about 110 mm, while the side sections have a longer chord length of about 220 mm. While the upper wing manages the turbulence in the middle, the larger chord length on both sides allows the part that does not need to manage the turbulence of the main ring 18 to generate greater downforce. In addition, the end plate 8 has a notch 13 near the trailing edge to guide the airflow direction.

[0033] The first lower beam wing 6 and the second lower beam wing 7 are distributed from front to back below the first flap 3 and the second flap 4, near the bottom of the end plate 8. They are used to manage the upward airflow brought by the diffuser and prevent the airflow from affecting the low-pressure area in the middle of the variable cross section airfoil group.

[0034] The end plate 8 is provided with louvers 9, an outer edge flange 11, and a guide strip 10. The blades of the louvers 9 are composed of small vanes, which can generate negative lift.

[0035] The end plate 8 has a V-shaped first notch 13 and a second notch 14 at the middle and rear of its upper edge, and a third notch 15 at the front of its lower edge. The first notch 13 is close to the tail edge of the upper beam wing 5. The louvers 9, the flange 11 and the guide strip 10 work together to reduce drag. The louvers 9 help to reduce drag. The guide strip 10 can guide the air flow on the end plate and reduce the generation of vortices. The flange 11 can not only increase the negative lift as a wind stabilizer, but also effectively improve the rigidity of the end plate 8 and extend the service life of the wind stabilizer.

[0036] Preferably, the main wing airfoil 2 is S1223, and the airfoil of the other winglets is E423.

[0037] The specific working process and principle of the above embodiments are as follows:

[0038] The variable cross-section wing assembly 1 of this vehicle features a small, continuous section raised in the middle of the overall wingspan to reduce the angle of attack, while the two sides have a larger angle of attack. The connection between the two parts is modeled using a Bezier curve for a smoother transition. The central section of the variable cross-section wing of the main wing 2 improves its adaptability to the flow separation from components such as the headrest 19. In the outer section, the influence of the updraft from the canard wing 16 is weakened by increasing the angle of attack of the winglets. The variable cross-section of the first flap 3 and the second flap 4 ensures that the horizontal and vertical distances from the trailing edge of the front wing to the leading edge of the rear wing remain consistent. Compared to ordinary variable cross-section wing assemblies, this variable cross-section wing assembly 1 has a smaller area in the projection region of the headrest 19 because the trailing edge of the main wing 2 is also raised. Furthermore, only a small area in the middle is raised, which facilitates further optimization by changing the raised length and interwing clearance to find a relatively better raised length and interwing clearance.

[0039] The upper beam wing 5, the first lower beam wing 6, and the second lower beam wing 7 further enhance the negative lift, making up for the loss of overall negative lift caused by the pressure relief of the louver 9. The upper beam wing 5 also straightens the airflow brought by the main ring 18 of the vehicle body frame. Since the upper beam wing 5 mainly sorts out the turbulent flow in the middle, the chords on both sides are designed to be larger so that the part that does not need to sort out the turbulent flow of the main ring 18 can generate greater downforce. Since the airflow will rise after passing through the diffuser 17, the first lower beam wing 6 and the second lower beam wing 7 are installed behind the end plate 8 to manage the rising airflow brought by the diffuser 17 and prevent its airflow from affecting the low-pressure area in the middle of the variable cross section airfoil group.

[0040] A louver structure 9 is provided at the end plate 8, connecting the inner and outer sides of the end plate 8. The end plate 8 also has a second notch 14. In conjunction with the louver 9, the airflow exiting the louver groove 9 flows through the second notch 14 into the area below the winglets and is released with the tail vortex, achieving a good drag reduction effect. Furthermore, the louver 9 blades are composed of small winglets, which also provide a certain amount of negative lift when the airflow passes through the louver 9, reducing the loss of overall negative lift caused by the pressure relief of the louver 9. The end plate 8 has guide strips 10, which, in conjunction with the louver 9, guide the airflow on the end plate 8, reducing the generation of vortices.

[0041] The large endplate 8 generates significant lateral force and also obstructs some airflow from reaching the vicinity of the wing surface, resulting in a reduction in the negative lift generated by the wing in this state compared to the straight-line state. Cutting off the lower front part of the endplate 8 to form the third notch 15 ensures the supply of airflow to the wing's operating area under yaw and crosswind conditions, guaranteeing the normal operation of the wing.

[0042] The above specific embodiments are only for illustrating the technical concept and structural features of the present invention, and are intended to enable those skilled in the art to implement them. However, the above content does not limit the scope of protection of the present invention. Any equivalent changes or modifications made in accordance with the spirit and essence of the present invention should fall within the scope of protection of the present invention.

Claims

1. A variable cross-section tail wing suitable for FSAE racing cars, comprising end plates (8) arranged opposite to each other on both sides, and a variable cross-section wing assembly (1) disposed between the two end plates (8), characterized in that: The variable cross-section wing assembly (1) includes a main wing (2), a first flap (3), and a second flap (4) arranged sequentially from the lower front to the upper rear of the end plate. The middle sections of the main wing (2), the first flap (3), and the second flap (4) are all small angle-of-attack sections, and the two ends connected to the end plate (8) are all large angle-of-attack sections. The small angle-of-attack sections and the large angle-of-attack sections are connected by a Bezier curve model. The horizontal and vertical distances from the trailing edge of the main wing (2) to the leading edge of the first flap (3) are consistent, and the horizontal and vertical distances from the trailing edge of the first flap (3) to the leading edge of the second flap (4) are consistent. The second flap (4) is provided with a Gurney flap (12) at the trailing edge, which is used to increase the curvature of the trailing edge of the airfoil and deflect the wake airflow upward. This can reduce the airflow separation on the airfoil before stall occurs, increase the upward momentum of the airflow near the trailing edge of the airfoil, and enhance the airfoil's resistance to adverse pressure gradient. It also includes an upper beam wing (5) disposed above the main wing (2). The two ends of the upper beam wing (5) are connected to the end plate (8). The upper beam wing (5) is an irregularly shaped wing with a central chord length that is half the chord length of the two sides, which is used to rectify the airflow brought by the main ring (18) of the vehicle body. The end plate (8) is provided with a louver (9). The blades of the louver (9) adopt a wing structure, which reduces the drag of the airflow as it passes through the louver (9) and provides negative lift.

2. The variable cross-section tail wing suitable for FSAE racing cars according to claim 1, characterized in that: A first notch (13) is provided on the end plate (8) near the trailing edge of the upper beam wing (5) to guide airflow.

3. The variable cross-section tail wing suitable for FSAE racing cars according to claim 1, characterized in that: It also includes a first lower beam wing (6) and a second lower beam wing (7) disposed between the end plates (8). The first lower beam wing (6) and the second lower beam wing (7) are arranged sequentially from front to back at the lower rear of the end plates (8) to manage the upward airflow brought by the diffuser (17) and prevent its airflow from affecting the low-pressure area in the middle of the variable cross section airfoil group (1).

4. The variable cross-section tail wing suitable for FSAE racing cars according to claim 1, characterized in that: The end plate has a second notch at the top of its rear edge to guide the airflow from the louvers.

5. The variable cross-section tail wing suitable for FSAE racing cars according to claim 4, characterized in that: The outer side of the end plate is provided with a guide strip, which is used to guide the air flow on the end plate in conjunction with the louvers and reduce the generation of eddies.

6. The variable cross-section tail wing suitable for FSAE racing cars according to claim 1, characterized in that: The outer edge of the end plate (8) is provided with a flange (11) to enhance the negative lift and the rigidity of the end plate (8).

7. The variable cross-section tail wing suitable for FSAE racing cars according to claim 1, characterized in that: A third notch (15) is provided below the leading edge of the end plate (8).

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