Automobile drag reduction control method and system based on accompanying wave generation device

Abstract

The invention discloses an automobile drag reduction control method and system based on a follow-up wave generation device, and relates to the technical field of active flow control, and the method comprises the steps that an exciter array distributed in a master-slave partition mode is arranged based on a key pneumatic area of a target vehicle; acquiring vehicle state data and flow field state data of the target vehicle in real time; acquiring a time delay and a space-time trigger sequence based on the vehicle state data; acquiring an external modulation frequency and a duty ratio of the exciter array based on the flow field state data; a high-voltage electric signal conforming to time delay, a space-time trigger sequence, external modulation frequency and a duty ratio is generated to serve as a control instruction; the exciter array is controlled to generate plasma volume force based on the control instruction, a follow-up wave regulation and control flow field is formed, and the aerodynamic resistance of the target vehicle is reduced. Generation and development of separation vortexes are actively regulated and controlled, flow separation is delayed, and a wake flow area is reduced, so that aerodynamic resistance of an automobile under various running working conditions is remarkably and stably reduced, and the energy efficiency ratio is increased.

Description

A method and system for vehicle drag reduction control based on a traveling wave generator Technical Field

[0001] This invention relates to the field of active flow control technology, and more specifically to a vehicle drag reduction control method and system based on a traveling wave generator. Background Technology

[0002] Currently, with the increasing severity of energy and environmental issues, reducing aerodynamic drag in automobiles to improve fuel economy or the driving range of electric vehicles has become an important research direction. Traditional drag reduction methods, such as optimizing vehicle body styling and adding fixed spoilers, have reached their optimization potential limits. Dielectric barrier discharge plasma exciters, as an emerging active flow control technology, have been widely studied in the field of aerospace drag reduction due to their advantages such as no moving parts, fast response speed, low energy consumption, and ease of surface integration. Their basic principle is to ionize air using a high-voltage alternating electric field to generate plasma, which, under the influence of the electric field gradient and Coulomb force, induces the formation of a wall jet, thereby altering the flow state of the boundary layer.

[0003] However, applying DBD plasma technology to automotive drag reduction still faces challenges: 1. Single excitation mode: Existing studies mostly use simple, fixed-frequency and voltage excitation, mainly to achieve boundary layer acceleration or suppression separation. The drag reduction effect is limited and unstable for complex automotive surfaces and time-varying incoming flow conditions. Moreover, the related control arrays use "discrete electrode independent drive" or "on-off array control", which can only generate local disturbances and cannot form a continuous and coordinated macroscopic flow field; 2. Low energy efficiency: There is a lack of efficient and precise control strategies for specific areas of the vehicle, such as the rear spoiler, A-pillar, and rear separation zone. In addition, the existing arrays are all "homogeneous drives" without functional division, resulting in "inefficient start-up" or "energy waste", which may lead to drag reduction benefits that are insufficient to offset the energy consumption of the exciter itself; 3. Lack of deep integration with vehicle body shape: The interaction between plasma-induced flow and vehicle body surface is not fully utilized to generate a flow field structure with global optimization effect.

[0004] Therefore, how to establish a multi-condition adaptive excitation mode and array-coordinated plasma flow control method to actively regulate the generation and development of separation vortices, thereby significantly and stably reducing the aerodynamic drag of automobiles under various driving conditions and improving the energy efficiency ratio, is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of the above problems, the present invention is proposed to provide a vehicle drag reduction control method and system based on a traveling wave generating device to overcome or at least partially solve the above problems. The method actively regulates the generation and development of the separation vortex, delays flow separation, and reduces the wake region, thereby significantly and stably reducing the aerodynamic drag of the vehicle under various driving conditions and improving the energy efficiency ratio.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] In a first aspect, embodiments of the present invention provide a vehicle drag reduction control method based on a traveling wave generation device, comprising: setting up an actuator array arranged in a master-slave partition based on the key aerodynamic regions of the target vehicle; acquiring vehicle state data and flow field state data of the target vehicle in real time; acquiring a time delay and a spatiotemporal trigger sequence based on the vehicle state data; acquiring an external modulation frequency and the duty cycle of the actuator array based on the flow field state data; generating a high-voltage electrical signal conforming to the time delay, the spatiotemporal trigger sequence, the external modulation frequency, and the duty cycle as a control command; and controlling the actuator array to generate plasma volume force based on the control command to form a traveling wave-regulated flow field, thereby reducing the aerodynamic drag of the target vehicle.

[0008] In another embodiment, the actuator array includes: a plurality of master actuators and slave actuators; the plurality of master actuators are arranged longitudinally along a flow separation initiation line determined by simulation or experiment to form a master actuator row for initiating the flow control process; the plurality of slave actuators are arranged in parallel rows at fixed intervals downstream of the master actuator rows along the flow direction to form a plurality of parallel slave actuator rows with fixed intervals, each slave actuator row may consist of a single actuator of a certain length, or may be discretely arranged in series of multiple single actuators to maintain the flow control effect initiated by the master actuator rows; the master actuator rows and the plurality of slave actuator rows together constitute the actuator array.

[0009] In another embodiment, the method for acquiring the vehicle state data and the flow field state data is as follows: acquiring the real-time driving speed of the target vehicle and the yaw rate characterizing the state change; the real-time driving speed and the yaw rate are used together as the vehicle state data; acquiring surface pressure pulsation data on one side of the exciter array in real time; acquiring the frequency signal of the tail vortex shedding of the target vehicle in real time; and using the surface pressure pulsation data and the frequency signal together as the flow field state data.

[0010] In another embodiment, the method for obtaining the time delay and the spatiotemporal trigger sequence is as follows: obtaining the correction coefficient of the target vehicle under the corresponding driving condition based on the yaw rate; obtaining the target phase velocity of the traveling wave based on the correction coefficient and the real-time driving speed; using the ratio of the fixed spacing and the target phase velocity as the time delay for activating adjacent actuator rows; determining the enable time of the master actuator row and each slave actuator row based on the time delay; and obtaining the spatiotemporal trigger sequence based on the order of the enable times.

[0011] In another embodiment, the method for obtaining the correction coefficient is as follows: the target vehicle is judged based on the yaw rate, and the corresponding correction coefficient is set according to different driving conditions: when the yaw rate is less than or equal to the condition judgment threshold, it is judged as a stable condition, and the initial coefficient of the stable condition is set as the correction coefficient of the current condition; when the yaw rate is greater than the condition judgment threshold and less than or equal to the saturation threshold, it is judged as a weak disturbance condition, and the correction coefficient of the current condition is obtained based on the initial coefficient of the stable condition and the maximum increment; when the yaw rate is greater than the saturation threshold, it is judged as a strong disturbance condition, and the maximum effective coefficient is set as the correction coefficient of the current condition.

[0012] In another embodiment, the method for obtaining the external modulation frequency is as follows: performing a fast Fourier transform based on the frequency signal to obtain a power spectral density function; using the frequency corresponding to the peak value of the power spectral density function as the dominant flow characteristic frequency; and using the dominant flow characteristic frequency as the external modulation frequency.

[0013] In another embodiment, the duty cycle is obtained by: extracting the pressure pulsation amplitude based on the surface pressure pulsation data; adjusting the working time of each exciter row based on the pressure pulsation amplitude and the energy efficiency target to obtain the corresponding actual working time; obtaining the external modulation period based on the external modulation frequency; and obtaining the duty cycle based on the ratio of the actual working time to the external modulation period.

[0014] In another embodiment, the larger the duty cycle, the more net energy is injected into the flow field during the external modulation period. The duty cycle needs to be increased or decreased in real time based on the flow field. The main actuator row has the highest duty cycle, and the duty cycles of each slave actuator row decrease sequentially from the closest to the farthest distance from the main actuator row.

[0015] In another embodiment, the method for generating the accompanying wave is as follows: based on the control command, the main actuator row is controlled to generate a local, upstream-pointing volume force pulse on the flow separation initiation line, generating a small, rotating vortex structure in the low-speed boundary layer as the initiating vortex; during the duration of the initiating vortex, the first downstream slave actuator row is activated after the time delay, generating a second vortex at a fixed distance from the main actuator row, and so on, with each slave actuator row generating ordered, continuously downstream-moving vortices according to the spatiotemporal triggering sequence, forming a dynamic accompanying wave full of kinetic energy between the surface of the target vehicle and the external mainstream.

[0016] Secondly, embodiments of the present invention provide a vehicle drag reduction control system based on a traveling wave generation device, comprising: an array arrangement module, a state data acquisition module, a related data acquisition module, a control command output module, and an aerodynamic drag reduction module; the array arrangement module is used to set up a master-slave partitioned actuator array based on the key aerodynamic regions of the target vehicle; the state data acquisition module is used to acquire vehicle state data and flow field state data of the target vehicle in real time; the related data acquisition module is used to acquire time delay and spatiotemporal trigger sequence based on the vehicle state data; and acquire external modulation frequency and duty cycle of the actuator array based on the flow field state data; the control command output module is used to generate a high-voltage electrical signal conforming to the time delay, the spatiotemporal trigger sequence, the external modulation frequency, and the duty cycle as a control command; the aerodynamic drag reduction module is used to control the actuator array to generate plasma volume force based on the control command, forming a traveling wave-controlled flow field to reduce the aerodynamic drag of the target vehicle.

[0017] As can be seen from the above technical solutions, compared with the prior art, the present invention discloses a vehicle drag reduction control method and system based on a traveling wave generation device, which has the following beneficial effects: 1. The present invention, by arranging a DBD plasma exciter array in the key aerodynamic parts of the vehicle and applying electrical excitation with a specific temporal and spatial distribution, induces a "traveling wave" type secondary flow field that moves synchronously with the incoming flow velocity on the vehicle body surface, thereby actively controlling the generation and development of separation vortices, delaying flow separation, and reducing the wake region, thereby significantly and stably reducing the aerodynamic drag of the vehicle under various driving conditions and improving the energy efficiency ratio.

[0018] 2. The "following wave" concept and implementation method based on plasma exciter proposed in this invention transforms discrete excitation into a continuous and coordinated macroscopic flow control structure, which is more in line with the laws of fluid mechanics, has a clear drag reduction mechanism, and has significant and stable effects.

[0019] 3. The hierarchical collaborative control strategy of this invention: spatiotemporal delay, external modulation frequency locking, duty cycle adjustment, and high-frequency output decoupling, realizes precise control of the entire path from macroscopic flow field rhythm to microscopic force field generation, and greatly improves energy utilization efficiency.

[0020] 4. Based on real-time flow field feedback, frequency locking and parameter adjustment enable the system to automatically adapt to various driving conditions: high-speed cruising, lane changing, crosswinds, and strong robustness.

[0021] 5. The "master-slave" array design has a clear objective, the flexible integration scheme does not affect the vehicle's appearance and safety, the whole system architecture is clear, and it is easy to implement and calibrate in engineering.

[0022] 6. The "master-slave" array of this invention integrates discrete plasma excitation points into a coherent, intelligent, and synchronous macroscopic flow control structure—the "following wave"—through precise spatial arrangement and precise temporal connection. The core function of this wave is to reshape the flow field topology at the rear of the vehicle or in the local separation zone, achieving a drag reduction effect similar to an ideal aerodynamic shape in an active and low-energy-consumption manner. This is the core innovation of this invention that distinguishes it from simple and chaotic excitation. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0024] Figure 1 is a flowchart of a vehicle drag reduction control method based on a traveling wave generation device provided in an embodiment of the present invention.

[0025] Figure 2 is a schematic diagram of the exciter structure provided in an embodiment of the present invention.

[0026] Figure 3 is a schematic diagram of the exciter array unit arrangement provided in an embodiment of the present invention.

[0027] Figure 4 is a schematic diagram of the spatiotemporal sequence of the exciter signal provided in an embodiment of the present invention.

[0028] Figure 5 is a schematic diagram of a vehicle drag reduction control system based on a traveling wave generation device provided in an embodiment of the present invention. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] As shown in Figure 1, this embodiment of the invention discloses a vehicle drag reduction control method based on a traveling wave generator, which includes the following steps. For ease of description, the steps are numbered S1 to S6. These numbers are not used to limit the sequential relationship of the various steps in this invention: S1. Based on the key aerodynamic regions of the target vehicle, an exciter array with master-slave partitioning is set.

[0031] Furthermore, the actuator array includes: multiple master actuators and slave actuators; multiple master actuators are arranged along the spanwise direction on the flow separation initiation line determined by simulation or experiment to form a master actuator row, which is used to initiate the flow control process; multiple slave actuators are arranged in parallel rows at fixed intervals downstream of the master actuator rows along the flow direction to form multiple slave actuator rows arranged in parallel at fixed intervals. Each slave actuator row can be composed of a single actuator of a certain length, or discretely arranged in series with multiple single actuators, which is used to maintain the flow control effect initiated by the master actuator rows; the master actuator rows and multiple slave actuator rows together constitute the actuator array.

[0032] Furthermore, in this embodiment, the exciter adopts a DBD plasma exciter, as shown in Figure 2. Each exciter is composed of exposed electrodes, a dielectric layer and embedded electrodes stacked from top to bottom, and encapsulated in a flexible insulating encapsulation layer, conformally fitting with the curved surface of the vehicle body.

[0033] Furthermore, key aerodynamic areas include: the lower surface of the rear spoiler, the edge of the tailgate, the A-pillar area, and the rear of the side windows.

[0034] Furthermore, the main actuator row is used to initiate the flow control process, and its working state directly determines whether the control will be triggered, just like a switch; as shown in Figure 3, multiple slave actuator rows are set downstream of the main actuator row and arranged in parallel along the flow direction at a fixed interval Δx. Their function is to amplify and maintain the flow control effect initiated by the main actuator row, guide and control the development path of the separation shear layer or vortex structure, and each actuator in the slave actuator row can be used as an independent control channel.

[0035] S2 acquires real-time vehicle status data and flow field status data of the target vehicle.

[0036] Furthermore, the methods for acquiring vehicle state data and flow field state data are as follows: acquiring the real-time driving speed of the target vehicle and the yaw rate characterizing the state change; the real-time driving speed and yaw rate are used together as vehicle state data; acquiring the surface pressure pulsation data on one side of the exciter array in real time; acquiring the frequency signal of the tail vortex shedding of the target vehicle in real time; and using the surface pressure pulsation data and frequency signal together as flow field state data.

[0037] Furthermore, in this embodiment, a vehicle speed sensor is used to collect the real-time driving speed V of the target vehicle. car The target phase velocity V of the traveling wave waveThe calculation provides core foundational data; a yaw rate sensor is used to collect yaw rate data characterizing changes in vehicle attitude such as steering and roll, used to determine driving conditions, such as lane changes and crosswind effects; a miniature surface pressure sensor array is used to collect surface pressure pulsation data near the exciter array area in real time, and signal processing can identify the intensity and location changes of flow separation, providing direct feedback for the adaptive adjustment of the duty cycle D: the more severe the separation, the greater the duty cycle to inject more energy; a microphone is used to monitor the frequency signal of the vehicle exhaust vortex shedding, which is the dominant flow field frequency f. s The extracted data provides support for frequency locking control in the energy modulation layer.

[0038] S3 is based on the time delay and spatiotemporal trigger sequence of vehicle status data acquisition.

[0039] Furthermore, the method for obtaining the time delay and spatiotemporal trigger sequence is as follows: obtain the correction coefficient of the target vehicle under the corresponding driving condition based on the yaw rate; obtain the target phase velocity of the traveling wave based on the correction coefficient and the real-time driving speed; use the ratio of the fixed spacing and the target phase velocity as the time delay for activating adjacent exciter rows; determine the enable time of the master exciter row and each slave exciter row based on the time delay; and obtain the spatiotemporal trigger sequence based on the order of the enable times.

[0040] Furthermore, the method for obtaining the correction coefficient is as follows: the target vehicle's driving condition is determined based on the yaw rate, and corresponding correction coefficients are set based on different driving conditions: when the yaw rate is less than or equal to the condition determination threshold, it is determined to be a stable driving condition, and the initial coefficient of the stable driving condition is set as the correction coefficient of the current driving condition; when the yaw rate is greater than the condition determination threshold and less than or equal to the saturation threshold, it is determined to be a weak disturbance driving condition, and the correction coefficient of the current driving condition is obtained based on the initial coefficient of the stable driving condition and the maximum increment; when the yaw rate is greater than the saturation threshold, it is determined to be a strong disturbance driving condition, and the maximum effective coefficient is set as the correction coefficient of the current driving condition.

[0041] Furthermore, under stable conditions where the target vehicle is cruising in a straight line with slight road disturbances, the correction coefficient k is set as the initial coefficient k0 of the stable condition baseline, k0∈[1.0,1.2], and in this embodiment k0 is set to 1.1; under weak disturbance conditions where the target vehicle is changing lanes normally with weak crosswinds, the correction coefficient k increases linearly with the yaw rate |ω|, the increment is proportional to the disturbance intensity, and the upper limit of the increase is limited by Δk. max Constraints are applied to ensure that the correction coefficient k ≤ 1.5; when the target vehicle is under strong disturbance conditions such as sharp turns and strong crosswinds, driving stability must be prioritized, and the correction coefficient k is locked at the maximum effective coefficient k. max Since increasing the correction coefficient k value further after exceeding the saturation threshold cannot improve the anti-disturbance effect, it will instead destroy the flow field coupling. At this time, driving stability should be prioritized.

[0042] Furthermore, based on the above constraints, the quantitative relationship between the correction coefficient k and the yaw rate |ω| is a piecewise function, ensuring that the correction coefficient k is reasonable under different driving conditions: ; where ω th The threshold value for determining the operating condition is set to 0.1 rad / s, used to distinguish between steady and disturbed operating conditions. Δk max =k max -k0 represents the maximum increment, fixed at 0.4 to ensure k does not exceed the upper limit; in this embodiment, the maximum effective coefficient k max Set to 1.5; ω sat This represents the saturation threshold, set to 0.5 rad / s, used to distinguish between weak and strong disturbance conditions.

[0043] Furthermore, the target phase velocity V wave =k×V car Among them, V car This indicates the real-time driving speed.

[0044] Furthermore, the time delay τ = Δx / V wave Wherein, Δx represents a fixed spacing, and in this embodiment, Δx is between 5 mm and 15 mm.

[0045] Furthermore, to achieve optimal coupling with the incoming flow, V is set... wave ≈ V car This means that the speed at which the "wave" moves downstream along the surface of the car body is roughly the same as the speed of the free flow outside the car.

[0046] Further, as shown in Figure 4, a spatiotemporal trigger sequence is generated: in each external modulation period T act Within the system, the master actuator is activated at time t0 by a high-voltage pulse (one or several cycles). The first slave actuator is activated at time t0+τ by the same pulse, the second slave actuator is activated at time t0+2τ by the same pulse, and so on. This sequence generates a spatial sense of "traveling wave". Each actuator operates under AC high voltage (such as a sine wave), generating periodic plasma volume force pulses. A single pulse can be approximated as an instantaneous "thrust" pointing upstream.

[0047] S4 obtains the external modulation frequency and the duty cycle of the exciter array based on the flow field state data.

[0048] Furthermore, the method for obtaining the external modulation frequency is as follows: a fast Fourier transform is performed on the frequency signal to obtain the power spectral density function; the frequency corresponding to the peak value of the power spectral density function is used as the dominant flow characteristic frequency; and the dominant flow characteristic frequency is used as the external modulation frequency.

[0049] Furthermore, a Fast Fourier Transform (FFT) is performed based on the frequency signal s(t) or the surface pressure pulsation data p(t) to obtain the power spectral density function PSD(f): PSD(f) = |FFT[x(t)]| 2 / T; where x(t) represents the input signal p(t) or s(t), T represents the signal sampling time, f represents the frequency variable, and FFT represents the Fast Fourier Transform; the frequency corresponding to the peak value of the power spectral density function PSD(f) is used as the dominant flow characteristic frequency f. s .

[0050] Furthermore, the present invention uses the external modulation frequency f of the system. act Set as with f s In this embodiment, f forms a specific relationship. act =f s This achieves frequency locking control, thereby synchronizing the macroscopic excitation rhythm with the flow field instability to reach the optimal intervention time; act Its core function is related to the dominant flow characteristic frequency f s Synchronization ensures that the timing of the excitation matches the development sequence of flow field instability, maximizing the intervention effect.

[0051] Furthermore, the duty cycle is obtained as follows: the pressure pulsation amplitude is extracted based on surface pressure pulsation data; the working time of each actuator row is adjusted based on the pressure pulsation amplitude (separation severity) and energy efficiency target to obtain the corresponding actual working time T. on The external modulation period T is obtained based on the external modulation frequency. act Based on actual working time T on With external modulation period T act The ratio of the two values ​​is used to obtain the duty cycle D.

[0052] Furthermore, the external modulation period T act =1 / f act .

[0053] Furthermore, the larger the duty cycle, the more net energy is injected into the flow field within the external modulation cycle. The duty cycle can be adjusted in real time based on the flow field requirements (such as the severity of separation): for severe separation, D increases by 50%-70%; for mild separation, D can be reduced to 30%-50%. The main actuator row has the highest duty cycle, and the duty cycles of each slave actuator row decrease sequentially from the closest to the farthest from the main actuator row. For example, the main actuator row has D=70%, the first slave actuator row has D=60%, the second slave actuator row has D=50%, and so on. This shapes the attenuation waveform of the "traveling wave" to better conform to the fluid energy dissipation law and improve energy efficiency. Continuous full duty cycle (D=100%) excitation should be avoided to prevent local flow field "saturation" from causing new instabilities. Intermittent excitation with 30%-70% duty cycle is used to achieve better control results.

[0054] Furthermore, the spatiotemporal triggering sequence clarifies the "activation time window" of each row of exciters: for example, from exciter row 1 from t0+τ to t0+τ+T. act (can be activated during the time period), external modulation frequency f act It needs to be synchronized with the dominant frequency of the flow field within this time window. The duty cycle D is used to allocate the actual working time of the exciter within this window. The three work together to achieve the timing control of the "wave-like" excitation. Refer to the spatiotemporal sequence diagram in Figure 4.

[0055] S5 generates a high-voltage electrical signal that conforms to the time delay, spatiotemporal trigger sequence, external modulation frequency, and duty cycle as a control command.

[0056] Furthermore, it also includes intensity modulation strategies: when the sensor detects strong flow separation in a certain area (such as a sudden drop in local pressure), the voltage amplitude of the corresponding actuator row in that area can be temporarily increased to inject greater momentum; to simulate natural wave decay, the excitation intensity (voltage) of the downstream actuator can be designed to be slightly lower than that of the upstream actuator to match the flow energy dissipation.

[0057] S6 uses control commands to control the exciter array to generate plasma volume force, forming a traveling wave to regulate the flow field and reduce the aerodynamic drag of the target vehicle.

[0058] Furthermore, the method for generating the traveling wave is as follows: based on control commands, the main exciter array generates a local, upstream-pointing volume force pulse on the flow separation initiation line, producing a small, rotating vortex structure in the low-speed boundary layer as the initial vortex; during the duration of the initial vortex, the first downstream slave exciter array is activated after a time delay, generating a second vortex at a fixed distance from the main exciter array, and so on. Each slave exciter array generates an ordered arrangement of vortices that continuously move downstream according to the spatiotemporal trigger sequence, forming a dynamic traveling wave full of kinetic energy between the surface of the target vehicle and the external mainstream.

[0059] Furthermore, the physical principle of the traveling wave is as follows: Within the boundary layer where the vehicle is about to separate at the rear, the aforementioned "relay" excitation creates a series of periodic vortex or high-speed jet disturbance sources that are spatially equidistant and temporally equal in phase. These disturbance sources are activated sequentially and orderly, and their combined effect in the flow field resembles a wave-like disturbance band moving downstream along the vehicle's surface. This "wave" is not a real matter wave, but rather a manifestation of phase motion induced in the flow field structure.

[0060] Further, the process of traveling wave generation and fluid dynamics mechanism: Step A, initiation and entrainment: The main exciter row first generates a local upstream-pointing volume force pulse at the separation initiation point, generating a small, rotating vortex structure in the low-speed boundary layer as the initiating vortex, and accelerating the local fluid; Step B, ordered entrainment and momentum transport: When the initiating vortex is not completely dispersed by the mainstream, the downstream slave exciter row 1 is activated after a delay time τ, generating a second vortex at a slightly downstream position, and has two key functions: (1) generating beneficial interaction (stretching, merging) with the vortex from the upstream; (2) entraining the upper fluid with higher momentum downward to the low-speed region near the wall. This process is passed downstream in sequence; Step C, formation of virtual wall and rectification: This series of ordered, continuously moving downstream vortices or high-speed fluid bands form a dynamic "virtual wall" or "momentum curtain" full of kinetic energy between the vehicle surface and the external mainstream as a traveling wave. This accompanying wave can better resist the huge reverse pressure gradient at the rear of the vehicle (deceleration and boost zone). Meanwhile, due to the wave speed V... wave ≈V car The relative velocity difference between this "virtual wall" and the external mainstream is greatly reduced, thereby significantly reducing shear stress and correspondingly reducing wall friction resistance.

[0061] Furthermore, the final drag reduction effect is manifested in the following ways: 1) Reduced pressure drag: The large-scale, low-energy wake zone that would have separated prematurely at the rear of the vehicle is supported and combed by the "following wave", which pushes the flow separation point downstream and even partially achieves "flow reattachment"; the reduction of the separation zone directly leads to a reduction in the negative pressure zone at the rear of the vehicle and a reduction in the front-to-rear pressure difference - this is the main source of drag reduction, which can contribute more than 70% of the total drag reduction.

[0062] 2) Frictional resistance optimization: Although the near-wall velocity gradient may increase locally due to disturbances, the overall flow adhesion is smoother because separation is suppressed. The global change in frictional resistance may be comprehensive, and the benefit is far less than the benefit of reducing pressure resistance.

[0063] 3) Suppressing vortex shedding: The ordered "traveling wave" disrupts the originally irregular, large-scale Kármán vortex street shedding frequency, breaking it into smaller-scale, higher-frequency vortices. These micro-vortices generate less momentum loss during dissipation.

[0064] Furthermore, it also includes a feedback adjustment phase: continuously collecting flow field state data (such as pressure pulsation changes and vortex shedding frequency changes) and vehicle state data after regulation, repeating steps S2-S6, and correcting V in real time. wave , τ, f act Parameters such as D are used to ensure that the system is always in the optimal drag reduction state.

[0065] Furthermore, it also includes operating condition adaptation: when the sensor detects changes in operating conditions (such as sudden changes in vehicle speed, abnormal yaw rate, or lane change / crosswind conditions), it quickly adjusts the k value (for example, increasing the k value during crosswinds to make V...). wave Slightly higher than V car (enhancing the traveling wave's resistance to lateral currents), f act The compatibility range with D ensures that the "traveling wave" matches the incoming flow and flow field characteristics under new operating conditions, maintaining the stability of the drag reduction effect.

[0066] As shown in Figure 5, in Embodiment 2, based on the same inventive concept, this embodiment of the invention also provides a vehicle drag reduction control system based on a traveling wave generation device, comprising: an array arrangement module, a state data acquisition module, a correlation data acquisition module, a control command output module, and an aerodynamic drag reduction module; the array arrangement module is used to set up a master-slave partitioned actuator array based on the key aerodynamic regions of the target vehicle; the state data acquisition module is used to acquire vehicle state data and flow field state data of the target vehicle in real time; the correlation data acquisition module is used to acquire time delay and spatiotemporal trigger sequence based on vehicle state data; and to acquire external modulation frequency and duty cycle of the actuator array based on flow field state data; the control command output module is used to generate a high-voltage electrical signal conforming to the time delay, spatiotemporal trigger sequence, external modulation frequency, and duty cycle as a control command; the aerodynamic drag reduction module is used to control the actuator array to generate plasma volume force based on the control command, forming a traveling wave to regulate the flow field and reduce the aerodynamic drag of the target vehicle.

[0067] Furthermore, in this embodiment, the functional implementation methods of each functional module correspond one-to-one with the methods described above, and will not be repeated here.

[0068] Based on the same inventive concept, the present invention also provides an electronic device, which includes a processor and a memory. The memory stores instructions, which are loaded and executed by the processor to implement a vehicle drag reduction control method based on a traveling wave generator as described in Example 1.

[0069] Based on the same inventive concept, the present invention also provides a computer device, including a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; the memory is used to store computer programs; and the processor, when executing the program stored in the memory, is able to implement a vehicle drag reduction control method based on a traveling wave generator as described in Embodiment 1.

[0070] The electronic device may include a processor, a communications interface, a memory, and a communication bus, wherein the processor, communications interface, and memory communicate with each other via the communication bus. The processor can call logical instructions in the memory to execute a vehicle drag reduction control method based on a traveling wave generator as described in Embodiment 1.

[0071] Furthermore, the logical instructions in the aforementioned memory can be implemented as software functional units and sold or used as independent products, and can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0072] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0073] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A vehicle drag reduction control method based on a traveling wave generator, characterized in that, include: An actuator array is set up in a master-slave partitioned manner based on the key aerodynamic regions of the target vehicle; Real-time acquisition of vehicle status data and flow field status data of the target vehicle; Based on the vehicle status data acquisition time delay and spatiotemporal trigger sequence; The external modulation frequency and the duty cycle of the exciter array are obtained based on the flow field state data. A high-voltage electrical signal conforming to the time delay, the spatiotemporal trigger sequence, the external modulation frequency, and the duty cycle is generated as a control command; based on the control command, the exciter array is controlled to generate plasma volume force, forming a traveling wave-controlled flow field to reduce the aerodynamic drag of the target vehicle.

2. The vehicle drag reduction control method based on a traveling wave generator according to claim 1, characterized in that, The actuator array includes: multiple master actuators and slave actuators; the multiple master actuators are arranged along the spanwise direction on a flow separation initiation line determined by simulation or experiment, forming a master actuator row for initiating the flow control process; the multiple slave actuators are arranged in parallel rows at fixed intervals downstream of the master actuator rows, forming multiple parallel slave actuator rows with fixed intervals, each slave actuator row may consist of a single actuator of a certain length, or may be discretely arranged in series of multiple single actuators, for maintaining the flow control effect initiated by the master actuator rows; the master actuator rows and the multiple slave actuator rows together constitute the actuator array.

3. The vehicle drag reduction control method based on a traveling wave generator according to claim 2, characterized in that, The method for obtaining the vehicle state data and the flow field state data is as follows: obtain the real-time driving speed of the target vehicle and the yaw rate characterizing the state change; The real-time driving speed and the yaw rate are used together as the vehicle state data; the surface pressure pulsation data on one side of the exciter array are acquired in real time; the frequency signal of the target vehicle's tail vortex shedding is acquired in real time; the surface pressure pulsation data and the frequency signal are used together as the flow field state data.

4. The vehicle drag reduction control method based on a traveling wave generator according to claim 3, characterized in that, The method for obtaining the time delay and the spatiotemporal trigger sequence is as follows: obtaining the correction coefficient of the target vehicle under the corresponding driving condition based on the yaw rate; obtaining the target phase velocity of the traveling wave based on the correction coefficient and the real-time driving speed; The ratio of the fixed spacing to the target phase velocity is used as the time delay for the activation of adjacent actuator rows; The enable times of the master actuator group and each of the slave actuator groups are determined based on the time delay. The spatiotemporal trigger sequence is obtained based on the order of the enabling moments.

5. The vehicle drag reduction control method based on a traveling wave generator according to claim 4, characterized in that, The method for obtaining the correction coefficient is as follows: the target vehicle's driving condition is determined based on the yaw rate, and corresponding correction coefficients are set based on different driving conditions: when the yaw rate is less than or equal to the driving condition determination threshold, it is determined to be a stable driving condition, and the initial coefficient of the stable driving condition is set as the correction coefficient of the current driving condition; when the yaw rate is greater than the driving condition determination threshold and less than or equal to the saturation threshold, it is determined to be a weak disturbance driving condition, and the correction coefficient of the current driving condition is obtained based on the initial coefficient of the stable driving condition and the maximum increment; when the yaw rate is greater than the saturation threshold, it is determined to be a strong disturbance driving condition, and the maximum effective coefficient is set as the correction coefficient of the current driving condition.

6. The vehicle drag reduction control method based on a traveling wave generator according to claim 5, characterized in that, The method for obtaining the external modulation frequency is as follows: performing a fast Fourier transform on the frequency signal to obtain a power spectral density function; using the frequency corresponding to the peak value of the power spectral density function as the dominant flow characteristic frequency; and using the dominant flow characteristic frequency as the external modulation frequency.

7. The vehicle drag reduction control method based on a traveling wave generator according to claim 6, characterized in that, The duty cycle is obtained as follows: the pressure pulsation amplitude is extracted based on the surface pressure pulsation data; the working time of each exciter row is adjusted based on the pressure pulsation amplitude and the energy efficiency target to obtain the corresponding actual working time; and the external modulation period is obtained based on the external modulation frequency. The duty cycle is obtained based on the ratio of the actual working time to the external modulation period.

8. The vehicle drag reduction control method based on a traveling wave generator according to claim 7, characterized in that, The larger the duty cycle, the more net energy is injected into the flow field during the external modulation period. The duty cycle needs to be increased or decreased in real time based on the flow field. The main actuator row has the highest duty cycle, and the duty cycles of each slave actuator row decrease sequentially from the closest to the farthest distance from the main actuator row.

9. A vehicle drag reduction control method based on a traveling wave generator according to claim 8, characterized in that, The method for generating the accompanying wave is as follows: based on the control command, the main actuator row is controlled to generate a local, upstream-pointing volume force pulse on the flow separation initiation line, generating a small, rotating vortex structure in the low-speed boundary layer as the initiating vortex; during the duration of the initiating vortex, the first downstream slave actuator row is activated after the time delay, generating a second vortex at a fixed distance from the main actuator row, and so on. Each slave actuator row generates an ordered arrangement of vortices that continuously move downstream according to the spatiotemporal triggering sequence, forming a dynamic accompanying wave full of kinetic energy between the surface of the target vehicle and the external mainstream.

10. A vehicle drag reduction control system based on a traveling wave generator, used to execute a vehicle drag reduction control method based on a traveling wave generator as described in any one of claims 1-9, characterized in that, include: The system includes an array arrangement module, a status data acquisition module, a relevant data acquisition module, a control command output module, and an aerodynamic drag reduction module. The array arrangement module is used to set up a master-slave partitioned actuator array based on the key aerodynamic areas of the target vehicle. The state data acquisition module is used to acquire vehicle state data and flow field state data of the target vehicle in real time; the related data acquisition module is used to acquire time delay and spatiotemporal trigger sequence based on the vehicle state data; and to acquire external modulation frequency and duty cycle of the exciter array based on the flow field state data; the control command output module is used to generate a high-voltage electrical signal that conforms to the time delay, the spatiotemporal trigger sequence, the external modulation frequency and the duty cycle as a control command; The aerodynamic drag reduction module is used to control the exciter array to generate plasma volume force based on the control command, forming a traveling wave-controlled flow field to reduce the aerodynamic drag of the target vehicle.

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