Composite pulse jet exciter, using method and aircraft
By using multiple sets of parallel solenoid valves and a signal-controlled composite pulse jet exciter, the problems of frequency limitation and single mode were solved, realizing high-frequency and multi-mode flow control and improving the accuracy and adaptability of flow control.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- LOW SPEED AERODYNAMIC INST OF CHINESE AERODYNAMIC RES & DEV CENT
- Filing Date
- 2026-04-13
- Publication Date
- 2026-05-12
AI Technical Summary
Existing pulse jet exciters are limited in frequency and have only one mode, making it difficult to achieve high-frequency excitation and multi-mode control, which limits their adaptability and control accuracy to complex flow fields.
By employing multiple sets of solenoid valves arranged in parallel, and combining airflow through a confluence channel, along with signal generator and host computer control, multi-channel independent control and coordination of solenoid valves with different timing sequences are achieved, thus expanding the frequency and mode of the excitation signal.
It breaks through frequency limitations, broadens excitation modes, improves the accuracy and adaptability of flow control, and achieves efficient flow control.
Smart Images
Figure CN122014726A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of aircraft technology, and in particular to a composite pulse jet exciter, a method of using it, and an aircraft. Background Technology
[0002] Active flow control technology effectively suppresses flow separation and significantly enhances lift by injecting momentum into the local flow field of an aircraft, supporting low-speed, short-distance takeoff and landing. Among these technologies, jet flow control has attracted considerable attention due to its stable performance and mature engineering applications. This technology relies on a jet actuator to convert the pressure energy of compressed gas into kinetic energy. Jet actuators are classified into two types based on the jet form: steady and pulsed. Steady actuators deliver continuous jets, resulting in high energy consumption; pulsed actuators deliver intermittent jets, offering advantages such as lower gas consumption, higher efficiency, and better control performance, and thus have greater development potential.
[0003] However, existing pulse jet exciters have two major bottlenecks: (1) Frequency limitation: relying on solenoid valves to control the switch, it is difficult to achieve the high frequency required by the flow field (it needs to match the characteristic frequency of the flow field), and it is prone to overheating and failure at high frequencies. Frequency improvement is constrained by cost and device performance; (2) Single mode: solenoid valves usually only support two states, "fully open" and "fully closed", and cannot realize continuous adjustable or half-open multi-mode excitation, which limits the adaptability and control accuracy of complex flow fields.
[0004] Therefore, how to overcome frequency limitations and expand the unsteady excitation working mode has become a key issue that needs to be addressed in pulse jet exciter technology. Summary of the Invention
[0005] This application discloses a composite pulse jet exciter to solve the technical problems of limited frequency and single mode in existing pulse jet exciters in related technologies.
[0006] To solve the above problems, this application adopts the following technical solution: In a first aspect, this application proposes a composite pulse jet exciter, which includes a confluence channel and multiple sets of solenoid valves. The multiple sets of solenoid valves are arranged in parallel and are connected to an air source. The confluence channel has multiple air inlet sections, the number of which is the same as the number of solenoid valves. The inlet of each air inlet section is connected to a solenoid valve. The confluence channel also includes a confluence section, the outlets of which are connected to the confluence section, so that the airflow passing through the multiple sets of solenoid valves merges in the confluence section.
[0007] The composite pulse jet exciter also includes a jet cavity, a contraction section, and a jet slot, and the outlet of the confluence channel is sequentially connected to the jet cavity, the contraction section, and the jet slot.
[0008] Furthermore, the solenoid valve includes a first solenoid valve and a second solenoid valve, the manifold is a Y-shaped flow channel, and the first solenoid valve and the second solenoid valve are respectively connected to the two inlets of the manifold.
[0009] Furthermore, a one-way valve is installed at the outlet of each intake section, and the one-way valve is configured such that the airflow flows from the intake section to the confluence section.
[0010] Furthermore, multiple sets of solenoid valves are electrically connected to a signal generator, which is electrically connected to a host computer. The host computer controls the opening and closing and frequency of the multiple sets of solenoid valves through the signal generator.
[0011] The technical solution adopted in this application can achieve the following beneficial effects: This application arranges multiple sets of solenoid valves in parallel, allowing the airflow controlled by these valves to combine in the confluence channel. By independently controlling the solenoid valves, the degree of freedom of the excitation signal is increased, breaking through the frequency limitation of the pulse jet exciter. Furthermore, the coordination of different timing controls of the multiple sets of solenoid valves broadens the excitation working modes of the pulse jet.
[0012] Secondly, this application proposes an aircraft that includes the composite pulse jet exciter of the first aspect. This aircraft has the same technical features as the composite pulse jet exciter provided in this application and can achieve the same technical effects, which will not be elaborated here.
[0013] Thirdly, this application proposes a method of using the composite pulse jet exciter of the first aspect, the method comprising the following steps: Based on the parameters and / or initial states of multiple sets of solenoid valves, and by controlling the opening, closing, and frequency of each set of solenoid valves, the operating mode of the composite pulse jet actuator is controlled. The operating modes of the composite pulse jet actuator include at least a multi-wave pulse jet mode, a frequency-doubling pulse jet mode, and a steady-state-pulse composite jet mode. This method has the same technical features as the composite pulse jet actuator provided in this application and can achieve the same technical effects; therefore, it will not be elaborated further here.
[0014] Furthermore, controlling the composite pulse jet exciter to be in multi-wave pulse jet mode includes the following operation steps: controlling multiple sets of solenoid valves to open and close in a timing mode with phase difference, and controlling multiple sets of solenoid valves to have the same frequency, so that multiple pulse jets are composite.
[0015] Furthermore, controlling the composite pulse jet exciter to be in frequency-doubled pulse jet mode includes the following operation steps: controlling multiple sets of solenoid valves to open and close in a timing mode with opposite phases, and controlling multiple sets of solenoid valves to have the same frequency, so that the frequency of the pulse jet after composite reaches frequency doubling.
[0016] Furthermore, controlling the composite pulse jet exciter to be in a steady-pulse composite jet mode includes the following operation steps: controlling at least one of the multiple sets of solenoid valves to remain normally open, and at least one of the remaining solenoid valves to remain in a pulse state, so that the steady jet and the pulse jet are combined. Attached Figure Description
[0017] To more clearly illustrate the technical solutions in the embodiments of this application 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 some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1 This is a schematic diagram of the structure of the composite pulse jet exciter in some embodiments of this application; Figure 2 This is a schematic diagram of the structure of the composite pulse jet exciter removing the signal generator, host computer and electrical connection components in some embodiments of this application; Figure 3 This is an outlet velocity waveform diagram of the first solenoid valve of the composite pulse jet exciter in multi-wave pulse jet mode in some embodiments of this application; Figure 4 This is an outlet velocity waveform diagram of the second solenoid valve in the multi-wave pulse jet mode of the composite pulse jet exciter in some embodiments of this application; Figure 5 This is an exit velocity waveform diagram of the composite pulse jet exciter in multi-wave pulse jet mode in some embodiments of this application; Figure 6 This is an outlet velocity waveform diagram of the first solenoid valve of the composite pulse jet exciter in frequency doubling pulse jet mode in some embodiments of this application; Figure 7 This is an outlet velocity waveform diagram of the second solenoid valve in the frequency doubling pulse jet mode of the composite pulse jet exciter in some embodiments of this application; Figure 8 This is an exit velocity waveform diagram of the composite pulse jet exciter in steady-pulse composite jet mode in some embodiments of this application; Figure 9 This is an outlet velocity waveform diagram of the first solenoid valve of the composite pulse jet exciter in the steady-pulse composite jet mode in some other embodiments of this application; Figure 10 This is an outlet velocity waveform diagram of the second solenoid valve in a steady-pulse composite jet mode of the composite pulse jet exciter in some other embodiments of this application; Figure 11This is an exit velocity waveform diagram of the composite pulse jet exciter in steady-pulse composite jet mode in some other embodiments of this application; Figures 3-11 The vertical axis represents the excitation amplitude, which is the jet slit exit velocity (dimensionless and for illustrative purposes only, not representing a specific value), and the horizontal axis represents time (dimensionless and for illustrative purposes only, not representing a specific value).
[0019] In the diagram: 100, manifold; 110, intake section; 120, manifold section; 130, check valve; 200, first solenoid valve; 300, second solenoid valve; 400, jet chamber; 500, contraction section; 600, jet slit; 700, signal generator; 800, host computer. Detailed Implementation
[0020] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be described in detail below. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0021] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.
[0022] There are two major bottlenecks in existing pulse jet exciters: (1) Frequency limitation: relying on solenoid valves to control the switch, it is difficult to achieve the high frequency required by the flow field (it needs to match the characteristic frequency of the flow field), and it is prone to overheating and failure at high frequencies. Frequency improvement is constrained by cost and device performance; (2) Single mode: solenoid valves usually only support two states, "fully open" and "fully closed", and cannot realize continuous adjustable or half-open multi-mode excitation, which limits the adaptability and control accuracy of complex flow fields.
[0023] This application sets multiple sets of solenoid valves in the pulse jet exciter, and combines the outlet airflow of multiple sets of solenoid valves through a confluence channel. The independent control of multiple solenoid valves improves the freedom of the excitation signal and breaks through the frequency limitation of the pulse jet exciter. The coordination of different timing controls of multiple sets of solenoid valves broadens the excitation working mode of the pulse jet.
[0024] The following is in conjunction with the appendix Figures 1 to 11 The traction structure, handle, and endoscope provided in this application will be described in detail through specific embodiments and application scenarios.
[0025] Reference Figure 1 and Figure 2 In a first aspect, this application proposes a composite pulse jet exciter, which includes a confluence channel 100 and multiple sets of solenoid valves. The multiple sets of solenoid valves are arranged in parallel and are connected to an air source. The confluence channel 100 has multiple air inlet sections 110, the number of which is the same as the number of solenoid valves. The inlet of each air inlet section 110 is connected to a solenoid valve. The confluence channel 100 also includes a confluence section 120, the outlets of which are all connected to the confluence section 120, allowing the airflow passing through the multiple sets of solenoid valves to converge in the confluence section 120. For example, as shown... Figure 1 and Figure 2 As shown, this composite pulse jet actuator can be applied to the field of active flow field control, such as suppressing boundary layer separation in aircraft, enhancing mixing efficiency, or regulating combustion stability. In a specific embodiment, each set of solenoid valves can be independently controlled to open and close according to a preset timing sequence, thereby generating pulsed airflows with specific phases, frequencies, and pulse widths in their respective inlet sections 110. These pulsed airflows then superimpose, interfere, or synergize in the confluence section 120 to form a composite pulse jet. Furthermore, by adjusting the opening timing of each solenoid valve, dynamic deflection of the jet direction or modulation of the pulse intensity can be achieved, further enhancing the actuator's adaptability to complex flow environments.
[0026] The composite pulse jet actuator also includes a jet cavity 400, a contraction section 500, and a jet slot 600, with the outlet of the confluence channel 100 sequentially connected to the jet cavity 400, the contraction section 500, and the jet slot 600. For example, the composite pulse jet actuator is sequentially connected to the jet cavity 400, the contraction section 500, and the jet slot 600 after the outlet of the confluence section 120 to achieve rectification, acceleration, and directional injection of the composite pulse airflow. Specifically, the pulse airflow from multiple sets of solenoid valves converges in the confluence section 120 and first enters the jet cavity 400. The jet cavity 400 acts as a buffer and pressure equalizer, helping to reduce flow disturbances caused by timing or pressure differences between the various inlet sections 110, making the airflow more uniform before entering the downstream structure. Subsequently, the airflow passes through the contraction section 500. The cross-sectional area of the contraction section 500 gradually decreases along the flow direction, and the airflow is accelerated in the contraction section 500, significantly increasing its kinetic energy, thereby enhancing the penetration and momentum transfer efficiency of the jet. Finally, the high-speed airflow is ejected through the slit-shaped jet slit 600, forming a pulse jet.
[0027] In this embodiment, by arranging multiple sets of solenoid valves in parallel, the airflow controlled by the multiple sets of solenoid valves is combined in the confluence channel 100. On the one hand, the independent control of the multiple solenoid valves increases the degree of freedom of the excitation signal and breaks through the frequency limitation of the pulse jet exciter. On the other hand, the coordination of different timing control of multiple sets of solenoid valves broadens the excitation working mode of the pulse jet.
[0028] In some embodiments, the solenoid valve includes a first solenoid valve 200 and a second solenoid valve 300, the manifold 100 is a Y-shaped flow channel, and the first solenoid valve 200 and the second solenoid valve 300 are respectively connected to the two inlets of the manifold 100. For example, as shown... Figure 1 and Figure 2 As shown, the composite pulse jet exciter uses a Y-shaped flow channel as the confluence channel 100. Its two inlets are connected to the first solenoid valve 200 and the second solenoid valve 300, respectively, and the outlet is connected to the jet cavity 400, the contraction section 500, and the jet slot 600 in sequence. During operation, the first solenoid valve 200 and the second solenoid valve 300 can be controlled independently, receiving compressed gas from the same or different gas sources respectively, and opening or closing according to a preset timing, frequency, and duty cycle, thereby generating pulse airflows with specific characteristics in their respective branches. When the two pulse airflows enter the Y-shaped confluence channel 100, they interact within the confluence section 120. For example, if the first solenoid valve 200 and the second solenoid valve 300 open synchronously with the same frequency and duty cycle, the two airflows superimpose to form a single pulse with enhanced amplitude; if there is a time delay between the two (such as a phase difference of 90° or 180°), but the frequencies are the same, a double-wave composite pulse jet with unchanged amplitude can be generated within the confluence section 120. After converging through the Y-shaped channel, the airflow enters the jet cavity 400 for pressure equalization, then accelerates through the contraction section 500, and finally is ejected from the jet slot 600.
[0029] In this embodiment, two sets of solenoid valves are configured, and correspondingly, the manifold 100 is also configured as a Y-shaped channel to merge the outlet airflow of the two sets of solenoid valves. The two sets of solenoid valves can break through the original pulse jet frequency limit and expand the original pulse jet frequency working mode. More sets of solenoid valves only provide more combination methods and higher frequency multiplication on this basis, but the basic working mode has not changed. By configuring two sets of solenoid valves, on the basis of breaking through the frequency and expanding the working mode, the mutual interference of too many solenoid valves is prevented, thereby enhancing the stability of the overall jet exciter.
[0030] In some embodiments, a one-way valve 130 is provided at the outlet of each intake section 110, and the one-way valve 130 is configured such that airflow flows from the intake section 110 to the confluence section 120. For example, Figure 1 and Figure 2As shown, the composite pulse jet exciter is equipped with a one-way valve 130 at the outlet of each intake section 110. The one-way valve 130 is configured to allow airflow to flow from the intake section 110 into the confluence section 120 in one direction only, while preventing the airflow from flowing back to the intake section 110 or the corresponding solenoid valve.
[0031] When multiple solenoid valves operate at different phases or pressures, without the check valve 130, the airflow from the high-pressure branch may backflow through the manifold 120 into the low-pressure or closed branch, causing distortion of the excitation signals in each channel and reducing control accuracy. The reverse airflow carrying pressure shocks may cause wear or damage to the precision components inside the solenoid valves. The check valve 130 isolates dynamic pressure fluctuations in the manifold 120, extending the service life of the solenoid valves. The check valve 130 ensures that the pulsed airflow generated by each solenoid valve enters the manifold 120 independently and completely, thereby maintaining the timing accuracy and momentum intensity of the composite jet.
[0032] For example, while the first solenoid valve 200 opens to generate a positive pulse, the second solenoid valve 300 is closed. Without the check valve 130, the high-pressure airflow from the first branch might rush into the second branch through the manifold 120, causing an abnormal increase in pressure at the outlet of the second solenoid valve 300, or even triggering a malfunction. However, with the check valve 130 installed, this reverse flow is effectively blocked, maintaining fluid isolation between branches and ensuring the controllability and reliability of the composite pulse jet.
[0033] In this embodiment, by providing a one-way valve 130 in each air intake section 110 of the confluence channel 100, backflow of airflow from different confluence sections 120 into the air intake section 110 is prevented, ensuring that the pulse airflow generated by each solenoid valve enters the confluence section 120 independently and completely, thereby maintaining the timing accuracy and momentum intensity of the composite jet.
[0034] In some embodiments, multiple sets of solenoid valves are electrically connected to a signal generator 700, which is electrically connected to a host computer 800. The host computer 800 controls the opening and closing and frequency of the multiple sets of solenoid valves through the signal generator 700. For example, Figure 1 As shown, multiple solenoid valves of the composite pulse jet exciter are electrically connected to a signal generator 700. The signal generator 700 is further connected to a host computer 800 (such as an industrial control computer or embedded controller) via a communication interface (such as USB, RS485, Ethernet, or CAN bus). The host computer 800 runs dedicated control software, which can flexibly set the driving parameters of each solenoid valve according to experimental or engineering needs, including the opening / closing sequence, operating frequency, duty cycle, phase difference, and number of pulses. The host computer 800 converts the above instructions into digital or analog control signals, which are then used by the signal generator 700 to generate corresponding drive pulse sequences, triggering the coils of each solenoid valve to precisely control the airflow.
[0035] In this embodiment, the signal generator 700 and the host computer 800 work together to control each group of solenoid valves, which can accurately and quickly realize the coil action of the solenoid valves and control their opening and closing sequence, operating frequency and duty cycle, etc.
[0036] Secondly, this application also proposes an aircraft that includes the composite pulse jet exciter of the first aspect. The method of using this exciter has the same technical features as the composite pulse jet exciter provided in this application and can achieve the same technical effects, which will not be elaborated further here.
[0037] Reference Figures 3-11 Thirdly, this application proposes a method of using the composite pulse jet exciter of the first aspect, the method comprising the following steps: Based on the parameters and / or initial states of multiple sets of solenoid valves, and by controlling the opening, closing, and frequency of each set of solenoid valves, the operating mode of the composite pulse jet actuator is controlled. The operating modes of the composite pulse jet actuator include at least a multi-wave pulse jet mode, a frequency-doubling pulse jet mode, and a steady-state-pulse composite jet mode. For example, such as... Figures 3-11 As shown, the composite pulse jet actuator includes two sets of solenoid valves: a first solenoid valve 200 and a second solenoid valve 300, as well as a Y-shaped manifold 100. The first solenoid valve 200 is set to have a flow rate of m1, a frequency of f1, and a duty cycle of DC1; the second solenoid valve 300 has a flow rate of m2, a frequency of f2, and a duty cycle of DC2. This composite pulse jet actuator can be used in various operating modes flexibly, depending on different flow control objectives, as detailed below: 1. Multi-wave pulse jet mode: In this mode, each group of solenoid valves operates independently at the same frequency but with a fixed phase difference. Since each group of solenoid valves is connected to different branches of the manifold 100 and each branch outlet is equipped with a check valve 130, the two pulse airflows will not backflow into each other within the manifold section 120, but will enter the manifold cavity at different times to form a composite multi-wave pulse jet.
[0038] 2. Frequency-doubled pulse jet mode: This mode coordinates the opening and closing timing of multiple solenoid valves to ensure that the equivalent pulse frequency of the output jet is an integer multiple of the operating frequency of a single solenoid valve. For example, if the first solenoid valve 200 and the second solenoid valve 300 open alternately with a phase difference of 180° and operate at the same frequency and duty cycle, the jet synthesized in the confluence section 120 will exhibit a pulse characteristic of approximately double the frequency. This mode can achieve a higher frequency equivalent excitation without increasing the response limit of a single solenoid valve, making it suitable for applications requiring high-frequency response but limited by the physical performance of the solenoid valves.
[0039] 3. Steady-pulse combined jet mode: In this mode, one set of solenoid valves remains normally open to provide a continuous steady airflow, while another set of solenoid valves opens pulsatingly at a set frequency, superimposing pulse components. For example, the first solenoid valve 200 is continuously conducting, forming the base jet; the second solenoid valve 300 opens periodically, superimposing high-intensity pulse disturbances onto the base jet. This mode combines the stability of a steady jet with the instantaneous high momentum characteristics of a pulsed jet, making it suitable for applications requiring both steady-state control and transient response, such as combustion chamber flame stabilization or dynamic stall delay control.
[0040] In actual operation, the host computer 800 sends instructions to the signal generator 700 according to the preset control strategy or real-time feedback signal to dynamically adjust the working parameters of each solenoid valve, thereby seamlessly switching between the above modes.
[0041] In this embodiment, the method of use significantly expands the functional boundaries of the composite pulse jet exciter through parameterized configuration and patterned control, enabling it to adapt to diverse fluid control needs and improve the accuracy and energy efficiency of active flow control.
[0042] In some embodiments, controlling the composite pulse jet exciter to be in a multi-wave pulse jet mode includes the following steps: controlling multiple sets of solenoid valves to open and close in a timing mode with a phase difference, and controlling the multiple sets of solenoid valves to have the same frequency, so that multiple pulse jets are composited. For example, as... Figures 3-5 As shown, the composite pulse jet exciter includes two sets of solenoid valves, a first solenoid valve 200 and a second solenoid valve 300, and a Y-type manifold 100. In use, when controlling the composite pulse jet exciter to be in multi-wave pulse jet mode, the following specific operations can be performed: The first solenoid valve 200 and the second solenoid valve 300 are set to have the same operating flow rate, operating frequency, and duty cycle (e.g., m1=m2=m=5 g / s, f1=f2=f=100 Hz, DC1=DC2=DC=0.10). However, their opening timing is precisely controlled by the host computer 800 and the signal generator 700 to ensure a fixed phase difference (e.g., ...). (180° or other arbitrary phase offset). Because the two sets of solenoid valves are connected to the two branches of the Y-type manifold 100, and each branch outlet is equipped with a one-way valve 130, the two pulse airflows will not backflow into each other within the manifold section 120, but will enter the manifold cavity at staggered times. For example: The first solenoid valve 200 opens at t = 0 ms, 10 ms, 20 ms... (corresponding to 100 Hz), generating the first pulse; The second solenoid valve 300 opens with a delay of 2.5 ms (corresponding to a 90° phase difference, since the period T = 10 ms), that is, it opens at t = 2.5 ms, 12.5 ms, 22.5 ms... generating the second pulse.
[0043] Two pulsed airflows with the same frequency, flow rate, and duty cycle but different phases are superimposed in the confluence section 120, buffered by the jet cavity 400, accelerated by the contraction section 500, and finally ejected from the jet slot 600. The jet velocity at the jet slot outlet of the composite pulse jet exciter will exhibit two waveforms, thus realizing a dual-wave pulse jet. Although the output of a single solenoid valve is a single-frequency pulse, due to the phase difference, the synthesized jet exhibits a multi-peak structure or modulated waveform in the time domain, that is, multiple pressure / velocity pulse peaks appear within one cycle, forming a dual-wave characteristic.
[0044] In this embodiment, this operating mode expands the unsteady mixing mode of pulsed jets, improves the exciter's adaptability to different operating conditions, and achieves efficient flow control. Furthermore, by adjusting the phase difference (e.g., continuously varying from 0° to 360°), fine control over the shape of the synthesized jet waveform, the number of peaks, and the energy distribution can be achieved, providing a highly flexible excitation method for flow control. This operating mode is particularly suitable for scenarios requiring enhanced time-domain perturbation complexity at a fixed frequency.
[0045] In some embodiments, controlling the composite pulse jet exciter to be in a frequency-doubled pulse jet mode includes the following steps: controlling multiple sets of solenoid valves to open and close in an inverse timing pattern, and controlling the multiple sets of solenoid valves to have the same frequency, so that the frequency of the pulse jet after composite pulse jet reaches a frequency doubled. For example, as... Figures 6-8 As shown, the composite pulse jet exciter includes two sets of solenoid valves, a first solenoid valve 200 and a second solenoid valve 300, and a Y-type manifold channel 100. When the composite pulse jet exciter is controlled in frequency-doubled pulse jet mode, the following operations can be performed: The operating flow rate, operating frequency, and duty cycle of the first solenoid valve 200 and the second solenoid valve 300 are set to be the same (e.g., m1=m2=m=5 g / s, f1=f2=f=100 Hz, DC1=DC2=DC=0.10), and the two are precisely controlled by the host computer 800 and the signal generator 700 to be in opposite phases (i.e., phase difference). The two solenoid valves open alternately in sequence. Specifically, when the first solenoid valve 200 is open, the second solenoid valve 300 is closed, and vice versa. Since the two sets of solenoid valves are connected to two symmetrical branches of the Y-shaped manifold 100, and each branch outlet is equipped with a check valve 130, the two airflows will not interfere with each other within the manifold section 120, but will be injected sequentially according to the set timing. For example: The first solenoid valve 200 opens at t=0 ms, 10 ms, 20 ms... (period T=10 ms, corresponding to 100 Hz) and lasts for 5 ms. The second solenoid valve 300 opens at t=5 ms, 15 ms, 25 ms... and also lasts for 5 ms, which is exactly the opposite of the first solenoid valve 200.
[0046] Thus, every 5 ms, one solenoid valve opens and generates a pulse jet. The two valves work alternately, ensuring that the flow section 120 receives an airflow pulse every half cycle (i.e., 5 ms). After pressure equalization in the jet cavity 400 and acceleration in the contraction section 500, the composite jet ejected from the jet slit 600 exhibits a pulse sequence with a period of 5 ms in the time domain, i.e., an equivalent output frequency of 200 Hz, achieving a double harmonic of the original solenoid valve's operating frequency (100 Hz). When solenoid valves A and B are opened simultaneously with their opening and closing controls in opposite phases (180° phase difference), the frequency of the composite pulse jet exciter reaches a double harmonic, i.e., 2f, with an equivalent duty cycle of 2DC.
[0047] In this embodiment, this operating mode can overcome the response limit of a single solenoid valve. Even limited by the mechanical response speed of the solenoid valve (e.g., the highest reliable operating frequency is 150 Hz), an equivalent excitation of 300 Hz can still be obtained through the anti-phase synergy of two valves. Moreover, this operating mode can achieve high-frequency excitation without using dedicated high-speed valves that are more expensive and have shorter lifespans, even with higher frequencies. Through the coordinated anti-phase control of multiple sets of solenoid valves at the same frequency, this frequency-doubling pulse jet mode effectively improves the dynamic response capability and flow control accuracy of the composite exciter without changing the physical limits of the hardware. In addition, if f is a medium frequency of the solenoid valve, this method can make the solenoid valve operate near the design point (rather than near the limit value), increasing the lifespan of the exciter while achieving a higher frequency pulse jet; if f is a high frequency of the solenoid valve, it can overcome the limits of existing solenoid valves and achieve a higher frequency pulse jet.
[0048] In some embodiments, controlling the composite pulse jet actuator to be in a steady-pulse composite jet mode includes the following steps: controlling at least one of a plurality of solenoid valves to remain normally open, and controlling at least one of the remaining solenoid valves to remain in a pulsed state, so that the steady jet and the pulse jet are combined. For example, Figures 9-11 As shown, the composite pulse jet actuator includes two sets of solenoid valves, a first solenoid valve 200 and a second solenoid valve 300, and a Y-type manifold 100. When the composite pulse jet actuator is controlled in steady-pulse composite jet mode, the following operations can be performed: The first solenoid valve 200 is kept normally open, continuously supplying air to form a stable and continuous steady jet. Simultaneously, the second solenoid valve 300 is controlled to periodically open and close according to a preset frequency (e.g., f = 80 Hz) and duty cycle (e.g., 20%), generating a high-intensity pulsed jet. The two airflows enter the Y-shaped confluence channel 100 through their respective inlet sections 110 (with a one-way valve 130 at the outlet). After superimposing within the confluence section 120, they flow sequentially through the jet cavity 400 and the contraction section 500, finally exiting from the jet slot 600 as a composite jet exhibiting both steady-state base flow and transient disturbance characteristics. The specific working process is as follows: Steady branch: After the first solenoid valve 200 is energized, it remains open, and compressed air continues to flow in, providing basic momentum flux; Pulse branch: The second solenoid valve 300 is driven by the signal generator 700 and opens intermittently at a frequency of 80 Hz. Each time it opens, a high momentum pulse airflow is injected into the confluence section 120, which superimposes periodic velocity / pressure disturbances on the steady jet. Synthetic effect: The time-averaged velocity at the 600 exit of the jet slit is dominated by the steady branch, while the instantaneous velocity presents a waveform with a baseline and a spike, which has both continuous control capability and strong transient excitation effect.
[0049] In this embodiment, steady-pulse jet control is implemented, overcoming the weakness in control capability caused by the absence of jet at the outlet of the traditional pulse jet gap, thus significantly enhancing the exciter's control capability. Furthermore, compared to the pure pulse mode, this mode consumes less energy (the steady branch can be maintained with a small flow rate). Compared to the pure steady mode, it has higher control sensitivity and can respond quickly to changes in flow. In addition, the pulse frequency or steady flow ratio can be dynamically adjusted via the host computer 800 to achieve a smooth transition from steady-state maintenance to strong disturbance intervention. Therefore, the steady-pulse composite jet mode is particularly suitable for active flow control scenarios that require a balance between stability and dynamic response capability.
[0050] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.
[0051] Furthermore, it should be noted that the scope of the methods and apparatus in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. In addition, features described with reference to certain examples may be combined in other examples.
[0052] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.
Claims
1. A composite pulse jet exciter, characterized in that, The system includes a manifold (100) and multiple sets of solenoid valves, wherein the multiple sets of solenoid valves are arranged in parallel and are connected to an air source. The manifold (100) has multiple air inlet sections (110), the number of which is the same as the number of solenoid valves. The inlet of each air inlet section (110) is connected to the solenoid valve. The manifold (100) also includes a manifold section (120), the outlets of which are connected to the manifold section (120) and the airflows passing through the multiple sets of solenoid valves are merged in the manifold section (120). The composite pulse jet exciter further includes a jet cavity (400), a contraction section (500), and a jet slit (600), and the outlet of the confluence channel (100) is sequentially connected to the jet cavity (400), the contraction section (500), and the jet slit (600).
2. The composite pulse jet exciter according to claim 1, characterized in that, The solenoid valve includes a first solenoid valve (200) and a second solenoid valve (300). The manifold (100) is a Y-shaped flow channel. The first solenoid valve (200) and the second solenoid valve (300) are respectively connected to the two inlets of the manifold (100).
3. The composite pulse jet exciter according to claim 1, characterized in that, Each of the intake sections (110) is provided with a one-way valve (130) at its outlet, and the one-way valve (130) is configured such that airflow flows from the intake section (110) to the confluence section (120).
4. The composite pulse jet exciter according to any one of claims 1-3, characterized in that, Multiple sets of solenoid valves are electrically connected to a signal generator (700), which is electrically connected to a host computer (800). The host computer (800) controls the opening and closing and frequency of the multiple sets of solenoid valves through the signal generator (700).
5. An aircraft, characterized in that, Includes the composite pulse jet exciter according to any one of claims 1-4.
6. A method of using the composite pulse jet exciter according to any one of claims 1-4, characterized in that, Includes the following steps: Based on the parameters and / or initial state of multiple sets of solenoid valves, and by controlling the opening and closing and frequency of each set of solenoid valves, the working mode of the composite pulse jet exciter is controlled, and the working mode of the composite pulse jet exciter includes at least a multi-wave pulse jet mode, a frequency doubling pulse jet mode, and a steady-state-pulse composite jet mode.
7. The method of using the composite pulse jet exciter according to claim 6, characterized in that, Controlling the composite pulse jet exciter to be in the multi-wave pulse jet mode includes the following operation steps: controlling multiple sets of solenoid valves to open and close in a timing mode with a phase difference, and controlling multiple sets of solenoid valves to have the same frequency, so as to combine multiple pulse jets.
8. The method of using the composite pulse jet exciter according to claim 6, characterized in that, Controlling the composite pulse jet exciter to be in the frequency-doubling pulse jet mode includes the following operation steps: controlling multiple sets of solenoid valves to open and close in a timing mode with opposite phases, and controlling multiple sets of solenoid valves to have the same frequency and duty cycle, so that the frequency of the pulse jet after composite reaches frequency doubling.
9. The method of using the composite pulse jet exciter according to any one of claims 6-8, characterized in that, Controlling the composite pulse jet exciter to be in the steady-pulse composite jet mode includes the following operation steps: controlling at least one of the multiple sets of solenoid valves to remain normally open, and at least one of the remaining solenoid valves to remain in a pulse state, so that the steady jet and the pulse jet are combined.