Rectifier system

Abstract

To provide a technique that improves stability of a vehicle body by suppressing vortex at a rear part of the vehicle body due to a boundary layer under a floor of the vehicle body.SOLUTION: A rectifier system rectifies the airflow flowing under a floor of a vehicle body and is provided with a duct including an intake port located within a predetermined range from a boundary layer of the airflow and an exhaust port located behind the boundary layer on the vehicle body, and a first vortex control device located within the duct and forming a first vortex. The first vortex suppresses the growth of a second vortex generated from the airflow.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a rectification system. [Background technology]

[0002] 2. Description of the Related Art Conventionally, techniques for controlling the airflow under the floor of a vehicle body are known.

[0003] For example, Patent Document 1 discloses a vehicle rear structure characterized by the placement of approximately triangular wing members under the rear floor of the vehicle, with the apex forward, symmetrically about the center line of the vehicle width, tilted at approximately 0° to the horizontal or with the rear end facing up, and spaced apart from the underfloor surface.

[0004] Patent Document 2 also discloses a vehicle underfloor structure that includes a high-frequency vortex generating section that is provided under the floor of the vehicle forward of the center line of the front wheels and includes at least one of a plurality of protrusions and a plurality of holes arranged along the vehicle width direction, and a vortex rectifying section that is provided under the floor rearward of the center of gravity of the vehicle and includes a plurality of fins arranged along the vehicle width direction, and the high-frequency vortex generating sections are arranged more densely in the center of the vehicle width direction than in parts other than the center of the vehicle width direction.

[0005] Patent document 3 also discloses an underfloor cover that is attached to the underside of a vehicle and has one or more openings for expelling foreign matter that has entered the vehicle, and that is characterized by having a vortex generator that is formed on the front side of the opening and protrudes downward toward the vehicle, turbulentizing the airflow flowing under the vehicle and forming a three-dimensional vortex.

[0006] Furthermore, Patent Document 4 discloses an air resistance reduction device characterized by having a movable wall provided at a position on the surface of a vehicle where a turbulent boundary layer occurs when the vehicle is traveling, and vibration means provided inside the movable wall to vibrate the movable wall. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-282076 [Patent Document 2] Japanese Patent Application Publication No. 2024-000302 [Patent Document 3] Japanese Patent Application Laid-Open No. 2013-212752 [Patent Document 4] Japanese Patent Application Publication No. 09-118270 Summary of the Invention [Problem to be solved by the invention]

[0008] The platform structure of an electric vehicle allows for a flatter underfloor area compared to the platform structure of a gasoline-powered vehicle, which has exhaust pipes and other components located under the floor of the vehicle. This allows for a lower aerodynamic resistance in an electric vehicle than a gasoline-powered vehicle. However, it has been found that a boundary layer generated under the floor of the vehicle can generate vortices behind the vehicle, which can affect the stability of the vehicle.

[0009] The purpose of the present disclosure, made in consideration of the above circumstances, is to provide a technology for improving the stability of a vehicle body by suppressing vortices behind the vehicle body caused by the boundary layer under the floor of the vehicle body. [Means for solving the problem]

[0010] A straightening system according to one embodiment of the present disclosure is a straightening system that straightens the airflow flowing under the floor of a vehicle body, and includes a duct including an intake port located within a predetermined range from the boundary layer of the airflow and an exhaust port located behind the boundary layer on the vehicle body, and a first vortex control device that is located within the duct and forms a first vortex, and the first vortex suppresses the growth of a second vortex generated from the airflow. [Effects of the Invention]

[0011] According to one embodiment of the present disclosure, the stability of the vehicle body can be improved by suppressing vortices behind the vehicle body caused by the boundary layer under the floor of the vehicle body. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic diagram illustrating a vehicle equipped with a rectifying system according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a schematic diagram illustrating a duct provided in the flow control system according to an embodiment of the present disclosure. [Figure 3] 1 is a schematic diagram of a duct provided in an airflow rectifying system according to an embodiment of the present disclosure, viewed from under the floor of a vehicle body. [Figure 4] 1 is a schematic diagram showing a first vortex control device provided in a rectification system according to an embodiment of the present disclosure. FIG. [Figure 5] 5 is a diagram illustrating a configuration example of the first vortex control device shown in FIG. 4. FIG. [Figure 6] 5 is a flowchart illustrating an example of the operation of the first vortex control device shown in FIG. 4. [Figure 7] FIG. 2 is a schematic diagram illustrating a second vortex control device provided in a rectification system according to an embodiment of the present disclosure. [Figure 8] FIG. 8 is a schematic diagram showing a modified example of the second vortex control device shown in FIG. 7. [Figure 9] 10A and 10B are diagrams illustrating effects obtained by a rectification system according to an embodiment of the present disclosure. [Figure 10] FIG. 10 is a diagram illustrating a comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In this specification and drawings, components having substantially the same functional configurations are designated by the same reference numerals, and redundant description will be omitted.

[0014] <1. Vehicle> Referring to FIG. 1, an example of a vehicle 1 equipped with a rectifying system 100 according to an embodiment of the present disclosure will be described. The vehicle 1 is a four-wheel electric vehicle that transmits drive torque output from a drive motor (not shown) serving as a drive power source to drive wheels. Unlike gasoline-powered vehicles, such electric vehicles do not have an exhaust pipe or the like disposed under the floor 2 of the vehicle body, and the underfloor 2 of the vehicle body is flat. The vehicle 1 is equipped with a secondary battery (not shown) that stores power to be supplied to the drive motor.

[0015] However, the vehicle 1 equipped with the rectification system 100 according to an embodiment of the present disclosure is preferably an electric vehicle as described above, but is not limited to this. The vehicle 1 may be a vehicle equipped with an internal combustion engine such as a gasoline engine or a diesel engine as a driving force source, or may be a vehicle equipped with both an internal combustion engine and a drive motor as driving force sources.

[0016] <2. Rectification system> 1 to 4, a straightening system 100 according to this embodiment will be described in detail. The straightening system 100 straightens the airflow flowing under the floor 2 of the vehicle body. The straightening system 100 includes at least a duct 10 and a first vortex control device 20. As shown appropriately in each drawing, in this specification, the longitudinal direction of the vehicle body may be referred to as the X direction, the vehicle width direction as the Y direction, and the vehicle height direction as the Z direction.

[0017] (2-1. Duct) Referring to FIG. 2, the duct 10 is a tubular member extending along the longitudinal direction (X direction) of the vehicle body on the vehicle interior side of the underfloor 2 of the vehicle body. The duct 10 takes in a portion of the air flowing under the underfloor 2 of the vehicle body while the vehicle 1 is traveling, and discharges a first vortex formed by a first vortex control device 20 (described later) toward the rear of the vehicle body. Also referring to FIG. 3, when the vehicle body is viewed from the underfloor 2, the duct 10 may be formed symmetrically with respect to the central axis of the vehicle body extending in the longitudinal direction (X direction) of the vehicle body. However, the present disclosure is not limited thereto. The shape of the duct 10 can be appropriately changed depending on the arrangement of various components mounted on the vehicle 1. The duct 10 may be made of a metal such as aluminum or steel, or a resin such as CFRP (Carbon Fiber Reinforced Plastics), but the present disclosure is not limited thereto. The duct 10 may be manufactured by known or any injection molding method, but the present disclosure is not limited thereto.

[0018] (intake port) Referring to FIG. 2, the duct 10 includes an inlet 11 provided within a predetermined range from a boundary layer B of the airflow flowing through the underfloor 2 of the vehicle body. Specifically, the inlet 11 opens on the outer surface (bottom surface) of the underfloor 2 of the vehicle body, forward in the longitudinal direction (X direction) of the vehicle body from a location where the boundary layer B occurs, which is determined, for example, through simulations or experiments, depending on the shape of the vehicle body. The shape of the inlet 11 may be a rectangle (e.g., quadrangle) or a substantially rectangle (e.g., square) extending in the vehicle width direction (Y direction) when the vehicle 1 is viewed from under the floor. From the viewpoint of fully demonstrating the function of preventing flow separation as a wind tunnel expansion section, the shape of the inlet 11 is preferably a trapezoid with the upper base located forward in the longitudinal direction (X direction) of the vehicle body and the lower base located rearward in the longitudinal direction (X direction) of the vehicle body, as shown in FIG. 3, and more preferably the angle θ is 10 degrees or less. However, the shape of the inlet 11 is not limited to these and can be determined depending on the shape of the vehicle body, for example, through simulations or experiments. In this disclosure, the term "boundary layer B" refers to a region in the airflow flowing along the underfloor 2 of the vehicle body where the flow velocity of the airflow decreases as it approaches the surface of the vehicle body.

[0019] (exhaust port) 2, 4, and 9, the duct 10 includes an exhaust port 12 provided rearward of the boundary layer B on the vehicle body. Specifically, the duct 10 may include a first exhaust port 12a provided below a diffuser on the vehicle body, and a second exhaust port 12b provided above the first exhaust port 12a on the vehicle body. More specifically, the first exhaust port 12a may open below the curved surface 3 of the diffuser, and the second exhaust port 12b may open below the rear end surface 4 of the vehicle body. However, the second exhaust port 12b may open above the curved surface 3 of the diffuser, or may open both above the curved surface 3 of the diffuser and below the rear end surface 4 of the vehicle body. In this disclosure, the term "diffuser" refers to an aerodynamic component that is attached to the lower side of the rear bumper or the like of a vehicle body and that diffuses the airflow flowing under the vehicle body floor 2, creating negative pressure on the bottom surface of the vehicle body and generating downforce. In addition, in this disclosure, the term "curved surface 3 of the diffuser" refers to a surface that slopes upward in the height direction (Z direction) of the vehicle body relative to the relatively flat bottom surface of the vehicle body under floor 2. In addition, in this disclosure, the term "rear end surface 4 of the vehicle body" refers to the end surface of the vehicle body where a tail lamp or the like is provided.

[0020] The shapes of the first exhaust port 12a and the second exhaust port 12b may both be rectangular (e.g., square) or substantially rectangular (e.g., square) extending in the vehicle width direction (Y direction). However, the shapes of the first exhaust port 12a and the second exhaust port 12b are not limited to this and can be determined according to the shape of the vehicle body, etc., through simulations, experiments, etc.

[0021] (slanted part) 2, the duct 10 may include an inclined portion 13 that continues from the intake port 11 and is inclined at a predetermined angle relative to the underfloor 2 of the vehicle body. The predetermined angle of inclination is preferably an acute angle from the viewpoint of efficiently taking in air into the duct 10, and more preferably is approximately 10 degrees or more and 45 degrees or less, although the present disclosure is not limited thereto.

[0022] (extension part) Referring to FIG. 2, the duct 10 may include an extension portion 14 that continues from the inclined portion 13 and extends along the vehicle front-rear direction (X direction). When viewed from the side of the vehicle body, the extension portion 14 may include a first extension portion 14a whose height in the vehicle height direction (Z direction) is constant, or a second extension portion 14b that continues from the first extension portion 14a and whose height in the vehicle height direction (Z direction) gradually increases toward the rear in the vehicle front-rear direction (X direction). Referring also to FIG. 3, when viewed from under the floor of the vehicle body, the length of the extension portion 14 along the vehicle width direction (Y direction) may gradually decrease from the front to the rear in the vehicle front-rear direction (X direction). However, the present disclosure is not limited thereto, and the length of the extension portion 14 along the vehicle width direction (Y direction) may be constant along the vehicle front-rear direction. The shape of the extension portion 14 may be rectangular (quadrilateral, etc.) or substantially rectangular (quadrilateral, etc.) extending in the vehicle width direction (Y direction) in the YZ cross section, but the present disclosure is not limited to this.

[0023] (Connection) Referring to FIG. 2, the duct 10 may include a first connecting portion 15a that continues from the extension portion 14 (specifically, the second extension portion 14b) and is connected to the first exhaust port 12a. The shape of the first connecting portion 15a may be rectangular (e.g., square) or substantially rectangular (e.g., square) extending in the vehicle width direction (Y direction) in a YZ cross section, but the present disclosure is not limited thereto. However, in the example shown in FIG. 2, the area of ​​the closed cross section of the first connecting portion 15a is smaller than the area of ​​the closed cross section of the extension portion 14 (specifically, the second extension portion 14b). The duct 10 may also include a second connecting portion 15b that continues from the extension portion 14 (specifically, the second extension portion 14b) and is connected to the second exhaust port 12b. The shape of the second connecting portion 15b may be a rectangle (e.g., quadrangle) or a substantially rectangle (e.g., quadrangle) extending in the vehicle width direction (Y direction) in the YZ cross section, but the present disclosure is not limited thereto. However, in the example shown in FIG. 2, the area of ​​the closed cross section of the second connecting portion 15b is smaller than the area of ​​the closed cross section of the extension portion 14 (specifically, the second extension portion 14b). The lengths of the first connecting portion 15a and the second connecting portion 15b along the vehicle body fore-and-aft direction (X direction) can be determined depending on the positions of the first exhaust port 12a and the second exhaust port 12b. However, the length of the first connecting portion 15a along the vehicle body fore-and-aft direction (X direction) is shorter than the length of the second connecting portion 15b along the vehicle body fore-and-aft direction (X direction).

[0024] 3, when viewed from under the floor of the vehicle body, the length of the connection portion 15 along the vehicle width direction (Y) may gradually decrease from the front to the rear in the vehicle front-rear direction (X direction), similar to the extension portion 14. However, the present disclosure is not limited to this, and the length of the connection portion 15 along the vehicle width direction (Y direction) may be constant along the vehicle front-rear direction.

[0025] (2-2. First vortex control device) 4, the first vortex control device 20 is provided in the duct 10 and forms a first vortex. As will be described in detail later, the first vortex suppresses the growth of a second vortex generated from the airflow flowing under the floor 2 of the vehicle body.

[0026] Here, the technical significance of providing the duct 10 and the first vortex control device 20 will be explained. Compared to the platform structure of a gasoline-powered vehicle, in which an exhaust pipe and other components are arranged under the floor 2 of the vehicle body, the platform structure of an electric vehicle allows for a flatter underfloor 2 of the vehicle body, resulting in reduced aerodynamic resistance. However, the present inventors conducted further research into aerodynamic resistance and found the following: As shown in FIG. 10 , a boundary layer B generated midway under the floor 2 of the vehicle body causes airflow to separate at the curved surface 3 of the diffuser, developing vortices. These vortices then separate again and intensify at the lower end of the rear bumper, potentially affecting vehicle stability. In particular, low-frequency fluctuations of a few Hz or less caused by the boundary layer B can grow into large vortices behind the vehicle body, potentially significantly affecting vehicle stability, including ride comfort. Therefore, the present inventors conducted extensive research and found that providing a duct 10 on the vehicle body and a first vortex control device 20 within the duct 10 can improve the airflow behind the vehicle body, thereby improving vehicle stability.

[0027] 4, the first vortex control device 20 may include first protrusions 21 (for example, a first lower protrusion 21a and a first upper protrusion 21b) that protrude upward from the vehicle body and extend along the vehicle width direction of the vehicle body. The number of first protrusions 21 can be set appropriately depending on the number of exhaust ports 12.

[0028] Referring to FIG. 4, first lower protrusion 21a may protrude upward in the vehicle height direction (Z direction) of the vehicle body from the underfloor 2 side of the inner wall surface of first connecting portion 15a. Also referring to FIG. 9, when vehicle 1 is traveling, when air taken in through intake 11 collides with first lower protrusion 21a, a first lower vortex corresponding to the first vortex and rotating substantially clockwise as viewed from the left side of the vehicle body is formed. This first lower vortex suppresses the growth of a second vortex immediately after it is generated from the lower end of curved surface 3 of the diffuser near first exhaust port 12a. The position of first lower protrusion 21a can be designed taking into account the generation position of the first lower vortex. For example, first lower protrusion 21a may be provided at a position three to five times (preferably about three times) the height of first lower protrusion 21a from first exhaust port 12a, but the present disclosure is not limited thereto. Furthermore, the first lower protrusion 21a may be a plate-shaped member extending in the vehicle width direction (Y direction) of the first connecting portion 15a. The first lower protrusions 21a may be provided intermittently at predetermined intervals along the vehicle width direction (Y direction) of the first connecting portion 15a, or may be provided continuously along the vehicle width direction (Y direction) of the first connecting portion 15a. The height of the first lower protrusion 21a in the vehicle height direction (Z direction) is a height that allows the first lower vortex to suppress the second vortex immediately after it is generated near the lower end of the curved surface 3 of the diffuser, and can be determined by simulation, experiment, or the like. However, the first lower protrusion 21a is not limited to the above-described shape and may be a triangular prism-shaped member extending in the vehicle width direction (Y direction) of the first connecting portion 15a. The first lower protrusion 21a may be made of a metal such as aluminum or steel, or a resin such as CFRP (Carbon Fiber Reinforced Plastics), but the present disclosure is not limited thereto. Furthermore, the first lower projection 21a can be produced by known or any injection molding method, but the present disclosure is not limited thereto.

[0029] The first upper protrusion 21b may protrude upward in the vehicle height direction (Z direction) of the vehicle body from the underfloor 2 side of the inner wall surface of the second connection portion 15b. Referring also to FIG. 9 , when the vehicle 1 is traveling, air taken in through the air inlet 11 collides with the first upper protrusion 21b, forming a first upper vortex that corresponds to the first vortex and rotates substantially clockwise when viewed from the left side of the vehicle body. This first upper vortex suppresses the growth of the second vortex that separates from the curved surface 3 of the diffuser near the second exhaust port 12b. The position of the first upper protrusion 21b can be designed taking into account the generation position of the first upper vortex. For example, the first upper protrusion 21b may be located at a position three to five times (preferably about three times) the height of the first upper protrusion 21b from the second exhaust port 12b, although the present disclosure is not limited thereto. The first upper protrusion 21b may also be a plate-shaped member extending in the vehicle width direction (Y direction) of the second connection portion 15b. The first upper protrusions 21b may be provided intermittently at predetermined intervals along the vehicle width direction (Y direction) of the second connecting portion 15b, or may be provided continuously along the vehicle width direction (Y direction) of the second connecting portion 15b. The height of the first upper protrusions 21b along the vehicle height direction (Z direction) is a height that allows the first upper vortex to suppress the growth of the second vortex separated from the bending surface 3 of the diffuser, and can be determined through simulation, experiment, or the like. However, the first upper protrusions 21b are not limited to the above-described shape and may be a triangular prism-shaped member extending in the vehicle width direction (Y direction) of the second connecting portion 15b. The first upper protrusions 21b may be made of metal such as aluminum or steel, or may be made of resin such as CFRP (Carbon Fiber Reinforced Plastics), although the present disclosure is not limited thereto. The first upper protrusions 21b may be manufactured by known or arbitrary injection molding, but the present disclosure is not limited thereto.

[0030] In this way, by applying the first lower vortex and the first upper vortex, which have opposite rotation directions and different strengths to the second vortex, to the second vortex, it is possible to prevent the second vortex from being strengthened at the lower end of the rear bumper as shown in Fig. 10. Note that the first vortex and the second vortex do not strengthen each other even if their phases coincide, as in the case of Karman vortices.

[0031] (2-3. Actuators, etc.) 1 and 5, the rectifying system 100 may further include an actuator 40 that moves the first protrusions 21 (e.g., the first lower protrusion 21a and the first upper protrusion 21b) in the vertical direction of the vehicle body based on the state of the airflow in the boundary layer B. The actuator 40 may be any known or arbitrary actuator that is electrically connected to the electronic control unit 60 and is capable of converting rotational motion output from a known or arbitrary motor (not shown) into linear motion based on a control signal from the electronic control unit 60. The actuator 40 may be electrically connected to the first protrusion 21 and move the first protrusion 21 in the vertical direction of the vehicle body by the linear motion described above.

[0032] The rectifying system 100 may also include a condition sensor 50 capable of detecting the condition of the airflow in the boundary layer B. The condition sensor 50 may be a known or arbitrary pressure sensor capable of detecting the pressure of the airflow flowing under the floor 2 of the vehicle body, or may be a known or arbitrary flow velocity sensor capable of detecting the flow velocity of the airflow flowing under the floor 2 of the vehicle body. The condition sensor 50 is electrically connected to an electronic control unit (ECU) 60 provided in the rectifying system 100.

[0033] That is, the electronic control unit 60 operates the actuator 40 based on the detection result of the status sensor 50, thereby moving the first protrusion 21 in the up-down direction of the vehicle body. Note that, when the first protrusion 21 includes a first lower protrusion 21 a and a first upper protrusion 21 b, the actuator 40 may be configured to be able to move each of the first lower protrusion 21 a and the first upper protrusion 21 b in the up-down direction of the vehicle body. The electronic control unit 60 may operate the actuator 40 based on the detection result of the status sensor 50, thereby moving each of the first lower protrusion 21 a and the first upper protrusion 21 b in the up-down direction of the vehicle body.

[0034] Here, the height of the first lower protrusion 21a in the vehicle height direction (Z direction) is correlated with the height of the first lower vortex in the vehicle height direction (Z direction). Referring also to FIG. 4, the first lower vortex is formed at a height position that is approximately three to five times the height of the first lower protrusion 21a in the vehicle height direction (Z direction) based on the inner wall surface of the first connecting portion 15a, which is located on the underfloor 2 side of the vehicle body. Similarly, the height of the first upper protrusion 21b in the vehicle height direction (Z direction) is correlated with the height of the first upper vortex in the vehicle height direction (Z direction). Referring also to FIG. 4, the first upper vortex is formed at a height position that is approximately three to five times the height of the first upper protrusion 21b in the vehicle height direction (Z direction) based on the inner wall surface of the second connecting portion 15b, which is located on the underfloor 2 side of the vehicle body. Therefore, the electronic control unit 60 may control the height position of the first lower protrusion 21a by operating the actuator 40 based on the state of the airflow in the boundary layer B detected by the state sensor 50 so as to form a first lower vortex that can suppress the second vortex immediately after its generation. Furthermore, the electronic control unit 60 may control the height position of the first upper protrusion 21b by operating the actuator 40 based on the state of the airflow in the boundary layer B detected by the state sensor 50 so as to form a first lower vortex that can suppress the second vortex that has separated from the bending surface 3 of the diffuser. This makes it possible to control the formation of the first vortex according to the state of the airflow in the boundary layer B, thereby further improving the stability of the vehicle body.

[0035] An example of the operation of the electronic control unit 60 will be described below with reference to a flowchart, also with reference to FIG. 6. Here, the electronic control unit 60 includes a processing unit 61 including one or more processors as shown in FIG. 1, and a storage unit 62 including one or more memories capable of communicating with the one or more processors. The storage unit 62 is assumed to have stored therein control information indicating the relationship between the pressure or flow velocity of the airflow in the boundary layer B, the size of the second vortex at the height position of the exhaust ports 12, 12a, and 12b, and the height positions of the first protrusions 21, 21a, and 21b for forming first vortices (first upper vortex and second upper vortex) capable of suppressing the second vortex. The control information is determined according to the vehicle conditions, such as the shape of the vehicle body and the vehicle speed and wind speed, and can be determined in advance, for example, by simulation or experiment.

[0036] In step S1, the processing unit 61 acquires the pressure or flow velocity of the airflow in the boundary layer B from the state sensor 50. Thereafter, the process proceeds to step S2.

[0037] In step S2, the processing unit 61 estimates the size of the second vortex at the height position of the exhaust port 12 based on the pressure or flow velocity of the airflow in the boundary layer B acquired in step S1. Specifically, the processing unit 61 estimates (acquires) the size of the second vortex corresponding to the pressure or flow velocity of the airflow in the boundary layer B acquired in step S1 by referring to control information pre-stored in the memory unit 62. Note that, if the exhaust port 12 includes a first exhaust port 12a and a second exhaust port 12b, the processing unit 61 estimates (acquires) the size of the second vortex at each of the height positions of the first exhaust port 12a and the second exhaust port 12b by referring to the control information pre-stored in the memory unit 62. Thereafter, the process proceeds to step S3.

[0038] In step S3, the processing unit 61 estimates the height position of the first protrusion 21 for forming a first vortex capable of suppressing the second vortex of the size estimated in step S2. Specifically, the processing unit 61 estimates (obtains) the height position of the first protrusion 21 for forming a first vortex capable of suppressing the second vortex of the size estimated in step S2 by referring to control information pre-stored in the storage unit 62. Note that if the first protrusion 21 includes a first lower protrusion 21a and a first upper protrusion 21b, the processing unit 61 estimates (obtains) the respective height positions of the first lower protrusion 21a and the first upper protrusion 21b by referring to the control information pre-stored in the storage unit 62. Thereafter, the process proceeds to step S4.

[0039] In step S4, the processing unit 61 generates a control signal for adjusting the height position of the first protrusion 21 to the height position calculated in step S4, and transmits the control signal to the actuator 40. As a result, the actuator 40 operates a motor (not shown) to adjust the height position of the first protrusion 21 to the height position estimated in step S2. If the first protrusion 21 includes a first lower protrusion 21a and a first upper protrusion 21b, the processing unit 61 generates a control signal for adjusting the respective height positions of the first lower protrusion 21a and the first upper protrusion 21b to the height positions calculated in step S4, and transmits the control signal to the actuator 40. This ends the process.

[0040] Incidentally, the actuator 40 may be a mechanically operated device such as a spring, or may be a hydraulically operated device such as a cylinder, instead of being operated by an electric signal.

[0041] (2-4. Second vortex control device) Referring to FIG. 1, the airflow straightening system 100 may further include a second vortex control device 30 located outside the duct 10 and under the floor 2 of the vehicle body, for controlling the second vortex. In this case, the second vortex control device 30 may include a second protrusion 31 that protrudes downward from the diffuser at the rear of the vehicle body and extends along the vehicle width direction (Y direction) of the vehicle body. Referring also to FIG. 9, when the vehicle 1 is traveling, air flowing under the floor 2 of the vehicle body that has not been taken in by the intake port 11 collides with the second protrusion 31, thereby forming a second vortex that is substantially counterclockwise as viewed from the left side of the vehicle body. Immediately after its formation, this second vortex is weakened by a first lower vortex that corresponds to the first vortex discharged from the first exhaust port 12a and is substantially clockwise as viewed from the left side of the vehicle body. The weakened second vortex then separates from the curved surface 3 of the diffuser rearward of the first exhaust port 12a, but is further weakened by the first upper vortex, which corresponds to the first vortex discharged from the second exhaust port 12b and rotates substantially clockwise when viewed from the left side of the vehicle, and is offset to an extent that does not affect the stability of the vehicle.

[0042] 7, the second protrusion 31 may be a triangular prism-shaped member extending in the vehicle width direction (Y direction). Specifically, the second protrusion 31 may be a triangular prism-shaped member and may include an inclined surface 31a inclined at a predetermined inclination angle from the underfloor 2 of the vehicle body and extending in the vehicle width direction (Y direction), and an upright surface 31b that stands from the lower end of the curved surface 3 of the diffuser toward the bottom of the vehicle body, is connected to the lower end of the inclined surface 31a, and extends in the vehicle width direction (Y direction). The predetermined inclination angle can be appropriately designed according to the shape of the vehicle body, for example, through simulation, experiment, etc. The second protrusions 31 may be provided in plurality at predetermined intervals along the vehicle width direction (Y direction), or may be provided continuously along the vehicle width direction (Y direction). However, the shape of the second protrusion 31 is not limited to the above-described shape. For example, instead of the erected surface 31b shown in Fig. 7, the second protrusion 31 may include a curved surface 32b that curves downward from the lower end of the bent surface 3 of the diffuser toward the bottom of the vehicle body and is connected to the lower end of the inclined surface 32a, as shown in Fig. 9. The second protrusions 31, 32 may be made of metal such as aluminum or steel, or may be made of resin such as CFRP (Carbon Fiber Reinforced Plastics), but the present disclosure is not limited thereto. The second protrusions 31, 32 can be manufactured by known or any injection molding method, but the present disclosure is not limited thereto.

[0043] (effect) As described above, the airflow straightening system 100 according to one embodiment of the present disclosure straightens the airflow flowing under the floor 2 of the vehicle body. The airflow straightening system 100 also includes a duct 10 including an intake port 11 provided within a predetermined range from the boundary layer B of the airflow and an exhaust port 12 provided rearward of the boundary layer B on the vehicle body. The airflow straightening system 100 also includes a first vortex control device 20 provided within the duct 10 and forming a first vortex. The first vortex control device 20 may include a first protrusion 21 that protrudes upward from the vehicle body and extends along the vehicle width direction of the vehicle body.

[0044] As described above, low-frequency fluctuations of a few Hz or less caused by boundary layer B can grow into large vortices behind the vehicle body, which can have a significant impact on the stability of the vehicle body, including ride comfort. However, with this configuration, the vortices behind the vehicle body caused by boundary layer B can be suppressed, thereby improving the stability of the vehicle body.

[0045] Moreover, the above-described airflow control system 100 may further include an actuator 40 that moves the first protrusion 21 in the vertical direction of the vehicle body based on the state of the airflow in the boundary layer B.

[0046] According to this configuration, the formation of the first vortex can be precisely controlled in accordance with the state of the airflow in the boundary layer B, thereby further improving the stability of the vehicle body.

[0047] The above-described straightening system 100 may further include a second vortex control device 30 for controlling the second vortex, located outside the duct 10 and under the floor 2 of the vehicle body. The second vortex control device 30 may include second protrusions 31, 32 that protrude downward from the diffuser at the rear of the vehicle body and extend along the vehicle width direction of the vehicle body.

[0048] According to this configuration, the second vortex that grows from the curved surface 3 of the diffuser toward the rear of the vehicle body due to the boundary layer B can be controlled, thereby further improving the stability of the vehicle body.

[0049] In addition, in the above-mentioned straightening system 100, it is preferable that the exhaust port 12 includes a first exhaust port 12a provided at the lower end of the diffuser of the vehicle body, and a second exhaust port 12b provided above the vehicle body relative to the first exhaust port 12a.

[0050] According to this configuration, the first vortex from the first exhaust port 12a can weaken the second vortex that is formed immediately after it is formed due to the boundary layer B, and the first vortex from the second exhaust port 12b can weaken the second vortex that has separated from the curved surface 3 of the diffuser, thereby further improving the stability of the vehicle body.

[0051] Although preferred embodiments of the present disclosure have been described in detail above with reference to the accompanying drawings, the present disclosure is not limited to such examples. It is clear that a person skilled in the art to which the present disclosure pertains can conceive of various modifications or alterations within the scope of the technical ideas described in the claims, and it is understood that these also naturally fall within the technical scope of the present disclosure. For example, the functions included in each component or step can be rearranged so as not to be logically inconsistent, and multiple components or steps can be combined or divided into one.

[0052] The following aspects also fall within the technical scope of the present disclosure. A vehicle equipped with a rectifying system that rectifies airflow flowing under the floor of the vehicle body, The rectification system is a duct including an intake port provided within a predetermined range from the boundary layer of the airflow and an exhaust port provided rearward of the boundary layer on the vehicle body; a first vortex control device disposed within the duct and configured to form a first vortex; Equipped with The first vortex suppresses the growth of a second vortex generated from the airflow. vehicle. [Explanation of symbols]

[0053] 1: vehicle, 100: straightening system, 10: duct, 11: intake, 12: exhaust port, 12a: first exhaust port, 12b: second exhaust port, 13: inclined portion, 14: extension portion, 14a: first extension portion, 14b: second extension portion, 15: connection portion, 15a: first connection portion, 15b: second connection portion, 20: first vortex control device, 21: first protrusion, 21a: first lower protrusion, 21b: second upper protrusion, 30: second vortex control device, 31, 32: second protrusion, 31a, 32a: inclined surface, 31b: upright surface, 32b: curved surface, 40: actuator, 50: status sensor, 60: electronic control unit, 61: processing unit, 62: memory unit

Claims

1. A rectifying system that rectifies airflow flowing under the floor of a vehicle body, a duct including an intake port provided within a predetermined range from the boundary layer of the airflow and an exhaust port provided rearward of the boundary layer on the vehicle body; a first vortex control device disposed within the duct and configured to form a first vortex; Equipped with the first vortex suppresses the growth of a second vortex generated from the airflow; Rectification system.

2. The first vortex control device includes a first protrusion that protrudes upwardly of the vehicle body and extends along a vehicle width direction of the vehicle body. The rectification system of claim 1 .

3. an actuator that moves the first protrusion in the vertical direction of the vehicle body based on the state of the airflow in the boundary layer; The rectification system of claim 2 .

4. a second vortex control device that is located outside the duct and under the floor of the vehicle body and that controls the second vortex; the second vortex control device includes a second protrusion that protrudes downward from the diffuser at the rear of the vehicle body continuously and extends along the vehicle width direction of the vehicle body; The rectification system of claim 1 .

5. The exhaust port includes a first exhaust port provided at a lower end of a diffuser of the vehicle body, and a second exhaust port provided above the first exhaust port of the vehicle body. The rectification system of claim 1 .

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