CN116331370A

CN116331370A - Variable cross section fin suitable for FSAE racing car

Info

Publication number: CN116331370A
Application number: CN202310443019.2A
Authority: CN
Inventors: 刘泳志; 高强; 刘睿; 王家刚; 崔津赫
Original assignee: Southeast University
Current assignee: Southeast University
Priority date: 2023-04-23
Filing date: 2023-04-23
Publication date: 2023-06-27

Abstract

The invention discloses a variable cross section tail fin suitable for an FSAE racing car, which comprises a variable cross section wing group, an upper beam wing, a first lower beam wing, a second lower beam wing and an end plate. The variable section wing group is composed of a main wing, a first flap and a second flap, three wings are variable section wings, the variable section wings are lifted up in a small whole section in the middle section of a wing span, the main wing, the first flap and the second flap are sequentially arranged between end plates on two sides and are distributed approximately in a diagonal line, the second flap is provided with a gurney flap, an upper beam wing is arranged on an end corner of the end plate, a first lower beam wing and a second lower beam wing are distributed at a position close to the bottom of the end plate, two end plates are symmetrically arranged on two sides, and the end plate is provided with a shutter, an end plate outer edge flanging, a front edge notch, a rear edge notch and a guide strip. The variable section wing can reduce the influence of the headrest on the turbulence and the like caused by the air flow, and can reduce the sliding of the air flow in the wingspan direction, so that the pressure distribution of the wing surface is more uniform, and the shutter structure can reduce the resistance.

Description

Variable cross section fin suitable for FSAE racing car

Technical Field

The invention relates to the technical field of aerodynamics, in particular to a variable cross section tail fin suitable for an FSAE racing car.

Background

In recent years, as the formula automobile university of universities in China rapidly progresses, various universities begin to put more effort into aerodynamic research. When racing car and air are moved relatively, the air can generate aerodynamic force and aerodynamic moment to racing car, so that the aerodynamic force of racing car has important influence on power performance and steering performance of racing car. Wherein the contribution quantity of the tail wing of the racing car is the largest, and can provide 35-45% of negative lift force for the racing car.

However, many motorcades in recent years are more conservative, most of adopted straight-plate type tail wings are parts positioned behind the heads of racing drivers, the tail wings are difficult to effectively utilize the air flow in the middle of the racing drivers due to the influence of the head rest, the negative lift force of the racing drivers cannot be effectively improved, some adopted variable section wings are only main wings, but flaps are not, the reason for doing so is that the tail wings of the main wings are not lifted, and the end plates are not universally provided with shutters, so that excessive resistance is generated under the condition of continuously pursuing the negative lift force, and many tail wings of the racing drivers do not consider the influence of the air flow brought by a diffuser and a main ring of a frame, and the diffuser is an aerologic set arranged at the bottom of the racing drivers, so that upward air flow can be generated while downward pressure is provided. It is therefore necessary to design a variable cross section tail suitable for FSAE racing cars.

Disclosure of Invention

The invention aims at overcoming the defects of the prior art and provides a variable cross section tail fin suitable for an FSAE racing car.

In order to solve the technical problems, the invention provides the following technical scheme:

the utility model provides a variable cross section fin suitable for FSAE racing car, includes the end plate that both sides set up relatively to and set up two variable cross section wing group between the end plate, its characterized in that: the variable cross-section wing group comprises a main wing, a first flap and a second flap which are sequentially arranged from the front lower part to the rear upper part of an end plate, wherein the middle sections of the main wing, the first flap and the second flap are small attack angle parts, the two ends connected with the end plate are large attack angle parts, the small attack angle parts and the large attack angle parts are connected through Bezier curve modeling, the horizontal distance and the vertical distance from the tail edge point of the main wing to the front edge point of the first flap are consistent, and the horizontal distance and the vertical distance from the tail edge point of the first flap to the front edge point of the second flap are consistent.

Further, the gurney flap is arranged at the trailing edge of the second flap and is used for increasing the camber of the trailing edge of the airfoil, so that the wake airflow is deflected upwards, the airflow separation of the airfoil can be reduced before stall occurs, the upward momentum of the airflow in the flow field of the trailing edge of the near airfoil is increased, and the stress-resistant gradient of the airfoil is enhanced.

Further, the automobile body main ring is characterized by further comprising an upper girder wing arranged above the main wing, wherein two ends of the upper girder wing are connected to the end plates, the upper girder wing is a special-shaped wing, the chord length of the middle part of the upper girder wing is half of the chord length of the two sides, and the upper girder wing is used for rectifying air flow brought by the automobile body main ring.

Further, a first notch is provided in the end plate at a position near the trailing edge of the upper beam for guiding the air flow.

Further, the device also comprises a first lower beam wing and a second lower beam wing which are arranged between the end plates, wherein the first lower beam wing and the second lower beam wing are sequentially arranged at the lower rear part of the end plates from front to back and are used for managing the upward air flow brought by the diffuser 17 and preventing the air flow from affecting the middle low pressure area of the variable section wing group.

Further, the end plate is provided with a shutter, and the blades of the shutter adopt a wing structure to provide negative lift force for the air flow when drag reduction is performed through the shutter.

Further, a second notch is arranged at the top of the rear edge of the end plate and is used for guiding airflow flowing out of the louver.

Further, the outside of the end plate is provided with a guide strip for matching with the louver to guide the air flow on the end plate, so that the generation of vortex is reduced.

Further, the outer side edge of the end plate is provided with a flanging for improving the negative lifting force and the rigidity of the end plate.

Further, a third notch is arranged below the front edge of the end plate.

Compared with the prior art, the invention has the beneficial effects that:

1. the variable cross section tail wing of the vehicle is lifted for a small whole section of the middle span, the attack angle of the middle part is small, the area of the main wing in a headrest projection area is reduced, the influence of turbulence caused by a headrest on the aerodynamic performance of the tail wing is avoided as much as possible, the attack angles of the two side parts are greatly suitable for the upward airflow caused by the front wing, the connection parts of the two parts are connected by using Bezier curve modeling, so that the transition is smoother, the flap is also a variable cross section wing, the horizontal distance and the vertical distance from the tail edge point of the front wing to the front edge point of the rear wing are kept consistent, and compared with the common variable cross section, the variable cross section wing group is lifted for the rear edge part of the main wing, so that the area of the main wing in the headrest projection area is smaller, and lifted for a small area in the middle part, the lifting length and the gaps between wings are conveniently and further optimized by changing the lifting length and the gaps between wings.

2. According to the invention, the upper beam wing, the first lower beam wing and the second lower beam wing further promote the negative lift force, the loss of the overall negative lift force caused by the pressure relief of the shutter is compensated, the upper beam wing realizes the rectification of the air flow brought by the main ring of the vehicle body frame, as the upper beam wing is mainly the middle part carding turbulence, the chord on two sides is designed to be larger, so that the part without the main ring turbulence can generate larger downward pressure, and as the air flow can rise through the diffuser, the first lower beam wing and the second lower beam wing are arranged below and behind the end plate, the upward air flow brought by the diffuser is managed, and the air flow is prevented from affecting the middle low pressure area of the variable-section wing group.

3. According to the invention, the louver structure is arranged at the end plate, the inner side and the outer side of the end plate are communicated, the end plate is provided with the rear edge notch, and the louver is matched with the louver, so that air flow flowing out of the louver groove can flow into the lower part of the wing piece through the rear edge notch and is released along with wake vortex, a good drag reduction effect is obtained, and the louver blades are composed of the small wing pieces, so that a certain negative lift force can be provided when the air flow passes through the louver, and the loss of the integral negative lift force caused by the pressure relief of the louver is reduced.

4. The end plate is provided with the guide strips, and the guide strips are matched with the shutters to guide the air flow on the end plate, so that the generation of vortex is reduced.

Drawings

FIG. 1 is a schematic diagram of the overall structure of an embodiment of the present invention;

FIG. 2 is a front view of an embodiment of the present invention;

FIG. 3 is a right side view of an embodiment of the present invention;

FIG. 4 is a side cross-sectional view of an embodiment of the present invention;

FIG. 5 is a schematic view of a variable section wing set according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of an embodiment of the present invention assembled to a vehicle;

wherein: 1-a variable cross-section wing set; 2-main wings; 3-a first flap; 4-a second flap; 5-upper beam wings; 6-a first lower girder wing; 7-a second lower girder wing; 8-end plates; 9-blinds; 10-a flow guiding strip; 11-flanging; 12-gurney flap; 13-a first gap; 14-a second notch; 15-a third gap; 16-front wing; 17-a diffuser; 18-a body main ring; 19-headrest.

Detailed Description

In order to enhance the understanding of the present invention, the present invention will be further described in detail with reference to the drawings, which are provided for the purpose of illustrating the present invention only and are not to be construed as limiting the scope of the present invention.

Fig. 1-6 show a variable section tail fin suitable for FSAE racing cars comprising a variable section wing set 1, an upper spar wing 5, a first lower spar wing 6, a second lower spar wing 7 arranged between two side end plates 8.

As shown in fig. 5, the variable section wing group 1 is composed 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 between two side end plates 8 in sequence, and are distributed in a substantially diagonal line from front lower side to rear upper side of the end plates 8. The component wings of the variable-section wing group 1 are all variable-section wings, the attack angle of the middle part is small, the area of the main wing in the projection area of the headrest 19 is reduced, the influence of turbulence caused by the headrest 19 on the aerodynamic performance of the tail wing is avoided as much as possible, the attack angle of the two side parts is greatly suitable for the upward airflow caused by the front wing 16, the connection part of the small attack angle part and the large attack angle part is connected by using Bezier curve modeling, the first wing flap 3 and the second wing flap 4 are also variable-section wings, the horizontal distance and the vertical distance from the tail edge point of the main wing 2 to the front edge point of the first wing flap 3 are kept consistent, the horizontal distance and the vertical distance from the tail edge point of the first wing flap 3 to the front edge point of the second wing flap 4 are kept consistent, and compared with the common variable-section wing, the variable-section wing group 1 is lifted by the rear edge part of the main wing 2, the area of the main wing 2 is smaller in the projection area of the headrest 19, and the middle part is lifted by a small area, the lifting length and the gap between the wing is further optimized by changing the lifting length and the gap between the lifting length and the wing gap are convenient to find relatively better lifting length and gap.

And the trailing edge of the second flap 4 is provided with a gurney flap 12 for increasing the camber of the trailing edge of the airfoil, so that the wake airflow is deflected upwards, the airflow separation of the airfoil can be reduced before stall occurs, the upward momentum of the airflow in the flow field near the trailing edge of the airfoil is increased, and the stress-resistant gradient of the airfoil is enhanced.

The upper beam wing 5 is a special-shaped wing, is arranged above the main wing 2, the middle section wing section has a short chord length of about 110mm, the two side section wing sections have a long chord length of about 220mm, the middle part of the upper beam wing is carded to form turbulence, the larger chords on the two sides can enable the turbulence part of the main ring 18 not to be tidied to generate larger downward pressure, and the end plate 8 is provided with a notch 13 at a position corresponding to the position close to the tail edge to guide airflow.

The first lower beam wing 6 and the second lower beam wing 7 are sequentially distributed below the first flap 3 and the second flap 4 from front to back and close to the bottom of the end plate 8, and are used for managing the upward airflow brought by the diffuser and preventing the airflow from affecting the middle low-pressure area of the variable-section wing group.

The end plate 8 is provided with a louver 9, an end plate outer edge flanging 11 and a guide strip 10. Wherein the blades of the shutter 9 are composed of small fins, and can generate negative lift force.

The end plate 8 is respectively provided with a V-shaped first notch 13 and a V-shaped second notch 14 in the middle and at the rear of the upper edge of the end plate, the front end of the lower edge of the end plate is respectively provided with a third notch 15, the first notch 13 is close to the tail edge of the upper beam wing 5, the louver 9, the flange 11 and the guide strip 10 are mutually matched, the louver 9 is beneficial to reducing resistance, the guide strip 10 can guide air to flow on the end plate, vortex generation is reduced, the flange 11 can serve as a fixed wing to lift negative lift force, meanwhile, the flange 11 can also effectively improve the rigidity of the end plate 8, and the service life of the fixed wing is prolonged.

Preferably, the main wing 2 airfoil is S1223 and the remaining airfoil airfoils are E423.

The specific working process and principle of the embodiment are as follows:

the whole span middle section of the variable-section wing group 1 of the vehicle is lifted by a small whole section, the attack angle is reduced, the attack angles of two side parts are large, the joints of the two parts are connected by using Bezier curve modeling, so that the transition is smoother, the middle section of the variable-section wing of the main wing 2 improves the adaptability to separating flows of components such as a headrest 19, the like, the outer section weakens the influence of the rising flow of the front wing 16 by increasing the attack angle of the wing, the horizontal distance and the vertical distance from the tail edge of the front wing to the front edge of the rear wing are kept consistent by the variable sections of the first wing 3 and the second wing 4, and compared with the common variable-section wing group 1, the rear edge part of the main wing 2 is lifted, so that the area of the main wing 2 in the projection area of the headrest 19 is smaller, the middle section is lifted by a small area, the lifting length and the gaps between the wings are conveniently and further optimized by changing the lifting length and the gaps between the wings.

The upper beam wing 5, the first lower beam wing 6 and the second lower beam wing 7 further promote negative lift, make up the loss of the overall negative lift caused by pressure relief of the louver 9, and the upper beam wing 5 realizes the rectification of the air flow brought by the main ring 18 of the vehicle body frame, because the upper beam wing 5 is mainly in the middle part for carding turbulence, the chords on two sides of the design are larger, so that the part without the turbulence of the main ring 18 can generate larger lower pressure, and because the air flow can rise through the diffuser 17, the first lower beam wing 6 and the second lower beam wing 7 are arranged below and behind the end plate 8, the upward air flow brought by the diffuser 17 is managed, and the air flow of the upper beam wing is prevented from affecting the middle low pressure area of the variable-section wing group.

The louver 9 structure is arranged at the end plate 8, the inner side and the outer side of the end plate 8 are communicated, a second notch 14 is formed in the end plate 8, the louver 9 is matched, air flow flowing out of the louver slot 9 can flow into the lower portion of the wing panel through the second notch 14 and is released along with wake vortex, a good drag reduction effect is obtained, the louver 9 blades are composed of small wing panels, a certain negative lift force is provided when the air flow passes through the louver 9, and loss caused by pressure release of the louver 9 to the whole negative lift force is reduced. The end plate 8 is provided with a flow guide strip 10 which is matched with the louver 9 to guide the air flow on the end plate 8, so that the generation of vortex is reduced.

The large size of the end plate 8 will generate a large lateral force and will also block part of the airflow from reaching the area near the airfoil, so that the negative lift generated by the airfoil in this state is reduced compared to a straight state. Cutting the area below the front part of the end plate 8 to form a third notch 15 can ensure the supply of air flow in the action area of the wing panel under the working conditions of yaw and side wind, and ensure the normal operation of the wing panel.

The foregoing detailed description will set forth only for the purposes of illustrating the general principles and features of the invention, and is not meant to limit the scope of the invention in any way, but rather should be construed in view of the appended claims.

Claims

1. The utility model provides a variable cross section fin suitable for FSAE racing car, includes end plate (8) that both sides set up relatively to and set up variable cross section wing group (1) between two end plate (8), its characterized in that: the variable cross-section wing group (1) comprises main wings (2), first flaps (3) and second flaps (4) which are sequentially arranged from the front lower part to the rear upper part of the end plate, wherein the middle sections of the main wings (2), the first flaps (3) and the second flaps (4) are small attack angle parts, the two ends connected with the end plate (8) are large attack angle parts, the small attack angle parts are connected with the large attack angle parts through Bezier curve modeling, the horizontal distance and the vertical distance from the tail edge point of the main wings (2) to the front edge point of the first flaps (3) are kept consistent, and the horizontal distance and the vertical distance from the tail edge point of the first flaps (3) to the front edge point of the second flaps (4) are kept consistent.

2. A variable cross section tail fin for an FSAE racing car in accordance with claim 1 wherein: and a gurney flap (12) is arranged at the trailing edge of the second flap (4) and is used for increasing the camber of the trailing edge of the airfoil, so that the wake airflow is deflected upwards, the airflow separation of the airfoil can be reduced before stall occurs, the upward momentum of the airflow in the flow field near the trailing edge of the airfoil is increased, and the stress-resistant gradient of the airfoil is enhanced.

3. A variable cross section tail fin for an FSAE racing car in accordance with claim 1 wherein: the novel automobile body main ring (18) comprises an upper beam wing (5) arranged above the main wing (2), wherein two ends of the upper beam wing (5) are connected to the end plate (8), the upper beam wing (5) is a special-shaped wing, the middle chord length of the upper beam wing is half of the chord length of two sides, and the upper beam wing is used for rectifying airflow brought by the automobile body main ring (18).

4. A variable cross section tail fin for an FSAE racing car in accordance with claim 3 wherein: a first notch (13) is arranged on the end plate (8) at a position close to the tail edge of the upper beam wing (5) and is used for guiding airflow.

5. A variable cross section tail fin for an FSAE racing car in accordance with claim 1 wherein: the novel variable-section wing group comprises end plates (8), and is characterized by further comprising a first lower beam wing (6) and a second lower beam wing (7) which are arranged between the end plates (8), wherein the first lower beam wing (6) and the second lower beam wing (7) are sequentially arranged at the lower rear part of the end plates (8) from front to back and are used for managing the upward airflow brought by a diffuser (17) and preventing the airflow from affecting a middle low-pressure area of the variable-section wing group (1).

6. A variable cross section tail fin for an FSAE racing car in accordance with claim 1 wherein: the end plate (8) is provided with a shutter (9), and blades of the shutter (9) adopt a wing structure to provide negative lift force for air flow while reducing drag through the shutter (9).

7. A variable cross section tail fin for an FSAE racing car in accordance with claim 6 wherein: the top of the rear edge of the end plate is provided with a second notch for guiding the airflow flowing out of the louver.

8. A variable cross section tail fin for an FSAE racing car in accordance with claim 6 wherein: the outside of the end plate is provided with a guide bar which is used for being matched with the louver to guide the air flow on the end plate, so that the generation of vortex is reduced.

9. A variable cross section tail fin for an FSAE racing car in accordance with claim 1 wherein: the outer side edge of the end plate (8) is provided with a flanging (11) for improving the negative lift and the rigidity of the end plate (8).

10. A variable cross section tail fin for an FSAE racing car in accordance with claim 1 wherein: a third notch (15) is arranged below the front edge of the end plate (8).