A vortex generator based on FSAE racing car

Abstract

The invention provides a vortex generator based on an FSAE racing car, comprising a vortex generator body, wherein the vortex generator body comprises a primary vortex generator and a secondary vortex generator, wherein the primary vortex generator is a pentahedral structure, wherein the primary vortex generator comprises an upper wedge-shaped plane, wherein the upper wedge-shaped plane comprises a front end straight line and two curved side edges connected to two end points of the front end straight line, wherein the free ends of the two curved side edges are arranged to intersect, wherein a front windward surface is vertically arranged at the front end straight line of the upper wedge-shaped plane, curved side surfaces are vertically arranged at both curved side edges of the upper wedge-shaped plane, wherein the height of the curved side surfaces gradually increases from the front windward surface to the rear, and wherein a lower wedge-shaped curved surface is arranged to connect the front windward surface and the curved side surfaces. The invention has the advantages of being small in size and being able to induce effective vortices upstream of a stall point of a wing, and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of fluid mechanics, and in particular relates to a vortex generator based on a FSAE racing car. Background Art

[0002] According to the current aerodynamic development of FSAE (Formula SAE) racing cars, the current technology used to delay flow separation is to place a baffle-type vortex generator in the normal direction of important aerodynamic surfaces, using its sharp edges to induce the occurrence of vortices, thereby delaying flow separation. However, existing racing vortex generators cannot accurately induce vortices upstream of the stall point of the wing, increasing the frontal area and resistance of the car. Summary of the invention

[0003] The problem to be solved by the present invention is to provide a vortex generator based on a FSAE racing car which is small in size and can induce effective vortices upstream of the stall point of the wing.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: a vortex generator based on FSAE racing car, including a vortex generator body, the vortex generator body including a primary vortex generator and a secondary vortex generator, the primary vortex generator is a pentahedral structure, the primary vortex generator includes an upper wedge-shaped plane, the upper wedge-shaped plane includes a front end straight line and two curved side edges connected to the two end points of the front end straight line, the free ends of the two curved side edges are arranged to intersect, a front windward surface is vertically arranged at the front end straight line of the upper wedge-shaped plane, curved side surfaces are vertically arranged at the two curved side edges of the upper wedge-shaped plane, the height of the curved side surfaces gradually increases from the front windward surface to the rear, and a lower wedge-shaped curved surface is arranged to connect the front windward surface and the curved side surfaces.

[0005] Furthermore, a height H1 of the curved side surface at the front windward surface is 0.5 mm, and a height H2 at the intersection of two curved side edges is 5 mm.

[0006] Furthermore, the length L1 of the front end straight line of the upper wedge-shaped plane is 20 mm, and the length L2 of the straight line of the upper wedge-shaped plane is 40 mm.

[0007] Furthermore, the secondary vortex generator is fixedly arranged on the upper wedge-shaped plane, and the primary vortex generator and the secondary vortex generator are an integrally formed structure.

[0008] Furthermore, the secondary vortex generator has a "teardrop" structure, the straight length L3 of the secondary vortex generator is 7.5 mm, and the highest point height H3 of the secondary vortex generator is 0.5 mm.

[0009] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0010] 1. The structure of the vortex generator body of the present invention adopts a structure combining a primary vortex generator and a secondary vortex generator. The primary vortex generator adopts a double-edge and wedge-shaped structure design. The front windward surface and the tail of the vortex generator both adopt a sharp edge structure, which can simultaneously induce two vortices with opposite rotation directions in the negative direction of the vehicle body coordinate system X, with high induction efficiency. At the same time, the secondary vortex generator can reduce the flow separation of the airflow in the vortex generator plane and help to improve the strength of the vortex induced by the vortex generator body.

[0011] 2. The volume of the vortex generator body of the present invention is small, that is, the area of ​​the vortex generator body projected onto the y-axis of the vehicle coordinate system is small, so the increase in the frontal area brought by the vortex generator body is negligible, effectively reducing the resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the overall structure of a vortex generator based on a FSAE racing car according to the present invention.

[0013] Figure 2 yes Figure 1 Schematic diagram of the main structure.

[0014] Figure 3 yes Figure 1 Schematic diagram of the top view structure.

[0015] Figure 4 yes Figure 1 Schematic diagram of the left view structure.

[0016] Figure 5 The present invention is a structural schematic diagram of a vortex generator based on a FSAE racing car installed on the lower surface of the main wing of the front wing of the racing car.

[0017] Figure 6 It is a contrast cloud diagram of the pressure on the lower surface of the front wing of the FSAE racing car before and after the vortex generator body is installed.

[0018] Figure 7 It is the streamline diagram of the vortex generator body on the lower surface of the negative lift wing at Y=0.5m in the FSAE racing coordinate system.

[0019] Figure 8 This is a velocity section comparison cloud diagram of the front wing combined wing at Y=0.5m in the FSAE racing coordinate system for the flow separation control effect on the front wing before and after the installation of the vortex generator body.

[0020] Fig. 9 It is the Q-criterion cloud diagram of the 0 isosurface of the influence range of the vortex surface on the entire FSAE racing car.

[0021] In the figure: 1-first-stage vortex generator; 2-second-stage vortex generator; 3-upper wedge-shaped plane; 4-front windward surface; 5-curved side surface; 6-lower wedge-shaped curved surface; 301-front end straight line; 302-curved side edge. DETAILED DESCRIPTION

[0022] The specific implementation modes of the present invention are described in detail below with reference to the accompanying drawings.

[0023] like Figure 1-Figure 4 As shown, a vortex generator based on a FSAE racing car includes a vortex generator body, wherein the vortex generator body includes a primary vortex generator 1 and a secondary vortex generator 2, wherein the primary vortex generator 1 is a pentahedral structure, wherein the primary vortex generator 1 includes an upper wedge-shaped plane 3, wherein the upper wedge-shaped plane 3 includes a front end straight line 301 and two curved side edges 302 connected to two end points of the front end straight line 301, wherein the free ends of the two curved side edges 302 are intersectingly arranged, and the upper wedge-shaped plane A front windward surface 4 is vertically arranged at the front straight line 301 of the surface 3, and curved side surfaces 5 are vertically arranged at the two curved sides 302 of the upper wedge-shaped plane 3. The height of the curved side surface 5 gradually increases from the front windward surface 4 to the rear, and a lower wedge-shaped curved surface 6 is arranged to connect the front windward surface 4 and the curved side surface 5. The curvature of the lower wedge-shaped curved surface 6 is determined by the airfoil curve of the lower surface of the negative lift wing of the front wing of the FSAE racing car. The structure of the vortex generator body of the present invention adopts a structure combining a primary vortex generator 1 and a secondary vortex generator 2. The primary vortex generator 1 adopts a double-edge and wedge-shaped structure design. The front windward surface 4 and the tail of the primary vortex generator 1 both adopt a sharp edge structure, which can simultaneously induce two vortices with opposite rotation directions in the negative direction of the vehicle body coordinate system X, and the induction efficiency is high. At the same time, the secondary vortex generator 2 can reduce the flow separation of the airflow in the plane of the vortex generator body, and help to improve the strength of the vortex induced by the vortex generator body.

[0024] Furthermore, a height H1 of the curved side surface 5 at the front windward surface 4 is 0.5 mm, and a height H2 at the intersection of the two curved side edges 302 is 5 mm.

[0025] Furthermore, the length L1 of the front end straight line 301 of the upper wedge-shaped plane 3 is 20 mm, and the straight line length L2 of the upper wedge-shaped plane 3 is 40 mm.

[0026] The volume of the vortex generator body of the present invention is small, that is, the area of ​​the vortex generator body projected onto the y-axis of the vehicle coordinate system is small, so the increase in the frontal area brought by the vortex generator body is negligible, effectively reducing the generation of resistance.

[0027] Furthermore, the secondary vortex generator 2 is fixedly arranged on the upper wedge-shaped plane 3, and the primary vortex generator 1 and the secondary vortex generator 2 are an integrally formed structure, so that the vortex generator body has good integrity, high product precision, smooth surface, and effectively reduces the generation of resistance.

[0028] Furthermore, the secondary vortex generator 2 has a "teardrop" structure, the straight length L3 of the secondary vortex generator 2 is 7.5 mm, and the highest point height H3 of the secondary vortex generator 2 is 0.5 mm. The secondary vortex generator 2 with a "teardrop" structure can reduce the flow separation of the airflow in the plane of the vortex generator body, and help to increase the strength of the vortex induced by the vortex generator body. Part of the airflow can generate small-scale vortices under the induction of the "teardrop" structure device, delaying the flow separation of the airflow in the plane of the primary vortex generator 1, and further inducing large-scale vortices under the double edge and wedge structure of the primary vortex generator 1.

[0029] Example

[0030] A vortex generator is an aerodynamic accessory used for local flow control. It uses its external structure to form vortices at the edge and transmit them downstream. The vortex generator installed on the FSAE racing car increases the flow's ability to resist adverse pressure gradient by promoting kinetic energy exchange between the downstream boundary layer and the outside world and forcing convection between the inner and outer layers of the near-wall flow, thereby delaying flow separation.

[0031] like Figure 5 As shown, the vortex generator bodies of the present invention are installed on the lower surface of the front wing of the FSAE racing car, arranged in parallel and at equal intervals, and installed longitudinally 25 mm upstream of the stall point on the lower surface of the front wing. Six vortex generators are installed on the main wings on both sides, and the trailing edges of two adjacent vortex generator bodies are spaced 50 mm apart. All vortex generator bodies are glued to the lower surface of the front wing of the racing car.

[0032] Compare the pressure on the lower surface of the front wing of the FSAE racing car before and after the vortex generator body of the present invention is installed. Figure 6 As shown, after the vortex generator body is installed, the area of ​​the maximum negative pressure zone increases, and the maximum negative pressure value increases, so that the front wing has a higher negative lift and negative lift coefficient, and after the vortex generator body is installed, when the airflow propagates from the maximum negative pressure to the direction of the arrow, the negative pressure area of ​​each pressure gradient increases due to the vortex generator's effect of enhancing the airflow's ability to resist the adverse pressure gradient, thereby improving the negative lift coefficient and improving the aerodynamic efficiency.

[0033] Specifically, the increase in the negative lift coefficient before and after the installation of the vortex generator was monitored, and the negative lift coefficient of the front wing when the vortex generator body was not installed as shown in Table 1 below was compared with the negative lift coefficient of the front wing when the vortex generator body was installed as shown in Table 2. When the two sets of simulation boundary conditions (vehicle speed is 15m / s) and the number of grids are basically equal, the negative lift coefficient gain brought by the vortex generator body to the front wing is about 0.0116. The vortex generator body enables the front wing to work under a condition with a smaller flow separation tendency, thereby increasing the negative lift coefficient of the front wing from 0.8921 to 0.9886, with an increase of 0.0965, and the negative lift coefficient improvement effect is obvious.

[0034] Table 1 Negative lift coefficient of the front wing when the vortex generator body is not installed

[0035]

[0036] Table 2 Negative lift coefficient of the front wing when the vortex generator body is installed

[0037]

[0038] In addition, the significance of the vortex induced by the vortex generator body is monitored, such as Figure 7 As shown, the flow from the windward side passes through the sharp edge of the vortex generator and is converted into a vortex with regular motion that can promote the exchange of kinetic energy between the downstream boundary layer and the outside world. The vortex effect is significant.

[0039] like Figure 8 As shown, by comparing the influence area of ​​the flow separation zone before and after the installation of the vortex generator body, it can be obviously observed that after the installation of the vortex generator body, due to its effect of delaying flow separation, the edge of the flow separation zone is reduced, and its influence area is smaller, so that the impact on the downstream flow field of the car, such as the rear wing and diffuser, is smaller, the aerodynamic efficiency is higher, and the front and rear axle loads caused by the negative lift of the car are more reasonably distributed.

[0040] like Fig. 9 As shown, an isosurface of the entire vehicle is created in the simulation software, the value is set to 0, the Q-criterion is applied, and the influence range of the vortex surface is observed. The vortex induced by the vortex generator body as shown in the figure has an obvious effect.

[0041] Therefore, the present invention can accurately induce vortex generation upstream of the stall point of the wing, delay the flow separation of important surfaces, improve the aerodynamic efficiency of the racing car, and the vortex effect is significant. At the same time, the structural design of the vortex generator body effectively reduces the frontal area and resistance of the racing car.

[0042] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A vortex generator based on FSAE racing car, characterized by: The invention comprises a vortex generator body, wherein the vortex generator body comprises a primary vortex generator (1) and a secondary vortex generator (2), wherein the primary vortex generator (1) and the secondary vortex generator (2) are integrally formed structures, wherein the primary vortex generator (1) is a pentahedral structure, wherein the primary vortex generator (1) comprises an upper wedge-shaped plane (3), wherein the upper wedge-shaped plane (3) comprises a front straight line (301) and two curved side edges (302) connected to two end points of the front straight line (301), wherein the free ends of the two curved side edges (302) are arranged to intersect, wherein a front windward surface (4) is vertically arranged at the front straight line (301) of the upper wedge-shaped plane (3), and curved side surfaces (5) are vertically arranged at the two curved side edges (302) of the upper wedge-shaped plane (3), wherein the height of the curved side surfaces (5) increases from the front windward surface (4) to the upper windward surface (4). The second-level vortex generator (2) is fixedly arranged on the upper wedge-shaped plane (3). The second-level vortex generator (2) has a "teardrop" structure. The straight length L3 of the second-level vortex generator (2) is 7.5 mm. The highest point height H3 of the second-level vortex generator (2) is 0.5 mm. The second-level vortex generator (2) is used to reduce the flow separation of the airflow on the plane of the vortex generator body, which helps to increase the intensity of the vortex induced by the vortex generator body. Under the induction of the second-level vortex generator (2) with a "teardrop" structure, part of the airflow generates a small-scale vortex, which delays the flow separation of the airflow on the plane of the first-level vortex generator (1). Under the structure of the first-level vortex generator (1), a large-scale vortex is further induced.

2. The vortex generator based on FSAE racing car according to claim 1, characterized in that: The height H1 of the curved side surface (5) at the front windward surface (4) is 0.5 mm, and the height H2 at the intersection of the two curved side edges (302) is 5 mm.

3. The vortex generator based on FSAE racing car according to claim 1, characterized in that: The length L1 of the front end straight line (301) of the upper wedge-shaped plane (3) is 20 mm, and the length L2 of the straight line of the upper wedge-shaped plane (3) is 40 mm.

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