Wing noise control device and control method based on jet-coupled sawtooth

Abstract

The present invention discloses a wing noise control device and control method based on jet-coupled serrations. The device is based on a passive wing noise control structure formed by a serration group located at the trailing edge of the wing, and an active wing noise control structure is arranged in the wing cavity. The active wing noise control structure is an active air path control structure, in which an air pipe is arranged in the wing cavity, one end of the air pipe is connected to the hollow serrations in the serration group, and the other end of the air pipe is connected to an external air source. The external air source introduces airflow into the hollow serrations in the serration group through the air pipe, and uses the tip holes and root holes of the serrations as jet holes, forming a one-to-one correspondence between the tip jet and the root jet, thereby achieving active wing noise control. Compared with a single active or passive control method, the present invention can achieve more significant noise reduction effects across the entire frequency range and under all operating conditions, further improving the acoustic performance of the wing, while also having lower energy consumption, high reliability, and simple operation.

Description

Technical Field

[0001] The present invention belongs to the technical field of aircraft wing flow noise control, and more particularly relates to a wing noise control device and a control method based on jet-coupled sawtooth. Background Art

[0002] With the rapid development of aviation, environmental noise pollution caused by aircraft is becoming increasingly severe, adversely affecting the health of nearby residents. Consequently, increasingly stringent airworthiness noise standards have been introduced. With the advancement of high-bypass turbofan engine technology, aircraft airframe noise has become a major noise source, with the wing being a key contributor, particularly the radiated noise from the wing's trailing edge. The airfoil is a fundamental element of an aircraft wing. Controlling its aerodynamic noise level, and thereby improving its acoustic properties, is crucial for obtaining airworthiness certification and enhancing international competitiveness.

[0003] Noise suppression methods based on flow control have attracted widespread attention in recent years. These methods can be categorized into active and passive control methods, depending on whether external energy is input. Regarding active control methods, Chinese patent CN111792022B, for example, discloses a trailing-edge airflow control method for suppressing rotor-vortex interference noise. This method adjusts the speed and direction of the airflow at the rotor's trailing edge according to flight conditions, thereby changing the load distribution on the rotor blade surface and reducing interference noise. Another example is Chinese patent CN108021772B, which discloses a jet-based method and system for reducing rotor noise. This method increases the area of ​​rotor noise reduction and improves the effectiveness of reducing thick noise. However, existing active control methods suffer from high energy consumption. Regarding passive control methods, Chinese patent application CN115892443A discloses a composite structure for reducing wing trailing-edge noise, comprising: a planar, sawtooth-shaped base structure, the bottom edge of which is connected to the wing trailing edge; and a layered structure covering at least one side of the base structure. For example, Chinese patent CN115949619B discloses a design method and impeller for a serrated trailing blade with a ridged surface structure. However, existing passive control methods suffer from the problem that their noise reduction effects are limited to a specific frequency range or under specific operating conditions, resulting in low noise reduction amplitude.

[0004] At the same time, the existing airfoil trailing edge noise control methods only involve a single active or passive control method, and the room for improving the acoustic performance of the wing airfoil is very limited. That is, there are shortcomings such as the noise reduction effect is only concentrated in a specific frequency band or specific working conditions, the noise reduction amplitude is low, and the energy consumption is large, making it difficult to meet multiple needs at the same time. Summary of the Invention

[0005] In order to avoid the shortcomings of the above-mentioned existing technologies, the present invention provides a wing noise control device and control method based on jet-coupled sawtooth, so as to enhance the suppression effect of wing aerodynamic noise, realize noise reduction in all frequency bands and all working conditions, and achieve the functions of greater noise reduction amplitude and lower energy consumption.

[0006] The present invention adopts the following technical solutions to solve the technical problems:

[0007] The wing noise control device based on jet-coupled serrations of the present invention is characterized in that: based on a passive wing noise control structure formed by a serration group located at the trailing edge of the wing, an active wing noise control structure is arranged in the wing cavity; the active wing noise control structure is an active air path control structure, in which an air pipe is arranged in the wing cavity, one end of the air pipe is connected to the hollow serrations in the serration group, and the other end of the air pipe is connected to an external air source, and the external air source introduces airflow into the hollow serrations in the serration group through the air pipe, with the tooth tip holes and tooth root holes of the serrations serving as jet holes, forming tooth tip jets and tooth root jets in a one-to-one correspondence, thereby realizing active wing noise control.

[0008] The wing noise control device based on jet-coupled sawtooth of the present invention is also characterized in that: the air pipe is configured as an inner and outer sleeve structure with adjustable length, and is composed of a fixed tube and a telescopic tube; the front end of the fixed tube reaches the root hole of the sawtooth to form a root jet; the front end of the telescopic tube reaches the tip hole of the sawtooth to form a tip jet; and noise control is achieved by adjusting the extended length of the telescopic tube to adjust the sawtooth length.

[0009] The wing noise control device based on the jet-coupled serrations of the present invention is also characterized in that an electric push rod is provided, the electric push rod is fixedly connected to the telescopic tube, and the electric push rod is used to adjust the extension length of the telescopic tube in real time to obtain a set noise reduction effect.

[0010] The wing noise control device based on jet-coupled serrations of the present invention is also characterized in that: the air pipe is a group of air pipe groups arranged in parallel, the front end pipe opening of each fixed pipe in the air pipe group is arranged in a one-to-one correspondence with the tooth root hole of each sawtooth, and the front end pipe opening of each telescopic pipe in the air pipe group is arranged in a one-to-one correspondence with the tooth dust hole of each sawtooth; the tail end pipe opening of each air pipe in the air pipe group is commonly connected to the diversion pipe, and the diversion pipe is connected to the air source through the main air pipe, and a filter and a flow controller are arranged in the main air pipe, and the flow controller is used to adjust the air flow of the main air pipe in real time to obtain the set noise reduction effect.

[0011] The characteristic of the wing noise control method based on jet-coupled sawtooth of the present invention is that the wing noise control device based on jet-coupled sawtooth is controlled according to the following method:

[0012] Step 1. Determine the geometric dimensions of the saw teeth, including: the wing span h, the number of saw teeth arranged in parallel n, the saw tooth width w of a single saw tooth, and the tooth root spacing s between adjacent saw teeth, where h = n(w + s); wherein the saw tooth width w is 10%-40% of the wing span h, the tooth root spacing s is 200%-400% of the wing trailing edge thickness t, and the wing trailing edge thickness t is the width of the jet hole;

[0013] Step 2: Based on computational fluid dynamics, deep neural networks, and genetic algorithms, with the jet flow rate Q and sawtooth length L as design variables and the far-field noise result SPL of the wing as the objective function, a proxy model of the objective function with respect to the design variables is established, and an iterative optimization strategy is constructed that couples the optimization process with neural network prediction. Based on the optimization strategy, the parameters of the optimal jet flow rate Q1 and the optimal sawtooth length L1 when the wing noise SPL is lowest under the current flight state are obtained. Repeat step 2 to obtain the parameters of the optimal jet flow rate Q1 and the optimal sawtooth length L1 corresponding to different flight states.

[0014] Step 3: The parameters of the optimal jet flow rate Q1 and the optimal sawtooth length L1 under different flight conditions obtained in step 2 are stored in the host computer. The host computer calls the parameters of the optimal jet flow rate Q1 and the optimal sawtooth length L1 under the corresponding state according to the flight state of the aircraft. By coordinated control of the jet flow rate and sawtooth length, active and passive integrated control of wing noise based on jet-coupled sawtooth is realized.

[0015] The characteristics of the wing noise control method based on jet-coupled sawtooth of the present invention are also as follows: the control process of setting the jet flow is: after the air source is turned on, the airflow is continuously output at the set power, the airflow flows through the filter, and then the airflow is output according to the optimal jet flow Q1 through the flow control meter, the output airflow is diverted by the diverter pipe and passes through the air pipe group to form a jet in the tooth root hole and tooth tip hole of the sawtooth group, thereby weakening the turbulent pulsation in the trailing edge area and reducing noise; the control process of setting the sawtooth length is: the telescopic air pipe group is driven to be extended and retracted by the electric push rod to obtain the optimal sawtooth length L1, so as to realize the destructive interference effect of the sound source generated by the sawtooth and thus weaken the noise.

[0016] Compared with the existing technology, the beneficial effects of the present invention are embodied in:

[0017] Compared with a single active or passive control method, the present invention can effectively couple the noise reduction effects of the active jet and passive sawtooth control methods, suppress the noise source intensity and radiation efficiency by weakening turbulent pulsations and generating destructive interference effects, and at the same time form a forced convection effect between the sawtooth teeth to further reduce the self-noise of the sawtooth, thereby achieving a more significant noise reduction amplitude in the full frequency range (100-10000Hz). At the same time, since the active and passive coupling methods can complement each other and enhance each other, while achieving more significant acoustic performance, it can also effectively reduce the energy consumption of the jet, and has the advantages of high reliability and simple operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A perspective view of an airfoil using the jet-coupled sawtooth technology in the control device of the present invention;

[0019] Figure 2 A partial view of the airfoil-shaped airflow tube and the serrations in the control device of the present invention;

[0020] Figure 3 A partial view of the electric push rod in the control device of the present invention;

[0021] Figure 4 This is a typical numerical simulation noise result diagram of the jet-coupled sawtooth airfoil of the present invention;

[0022] Figure 5 This is a typical numerical simulation energy consumption result diagram of the jet-coupled serrated airfoil of the present invention.

[0023] Numbers in the figure: 1 wing, 2 air source, 3 main air pipe, 4 first support frame, 5 filter, 6 flow control meter, 7 second support frame, 8 diversion pipe, 9 third support frame, 10 electric push rod, 11 air pipe, 12 sawtooth group, 13 fixed pipe, 14 telescopic air pipe. DETAILED DESCRIPTION

[0024] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0025] See also Figure 1 、 Figure 2 and Figure 3In this embodiment, the structure of the wing noise control device based on jet-coupled serrations is configured as follows: based on the passive wing noise control structure formed by the serration group 12 located at the trailing edge of the wing 1, an active wing noise control structure is arranged in the cavity of the wing 1; the active wing noise control structure is an active air path control structure, in which an air pipe 11 is arranged in the cavity of the wing 1, one end of the air pipe 11 is connected to the hollow serrations in the serration group 12, and the other end of the air pipe 11 is connected to an external air source 2. The air source 2 introduces airflow into the hollow serrations in the serration group 12 through the air pipe 11, and uses the tooth tip holes and tooth root holes of the serrations as jet holes, forming tooth tip jets and tooth root jets in a one-to-one correspondence, thereby achieving active wing noise control; the serration group 12 is located at the trailing edge of the wing 1.

[0026] In specific implementation, the corresponding technical measures also include:

[0027] like Figure 2 and Figure 3 As shown, the air pipe 11 is configured as an inner and outer sleeve structure with adjustable length, which is composed of a fixed tube 13 and a telescopic tube 14; the front end of the fixed tube 13 reaches the root hole of the saw teeth to form a root jet; the front end of the telescopic tube 14 reaches the tip hole of the saw teeth to form a tip jet; the length of the saw teeth is adjusted by adjusting the extended length of the telescopic tube 14 to achieve noise control.

[0028] An electric push rod 10 is provided, and the electric push rod 10 is fixedly connected to the telescopic tube 14 . The electric push rod 10 is used to adjust the extension length of the telescopic tube 14 in real time to obtain a set noise reduction effect.

[0029] In this embodiment, the air pipe 11 is a group of air pipes arranged in parallel, the front end pipe opening of each fixed pipe in the air pipe group is set in a one-to-one correspondence with the tooth root hole of each sawtooth, and the front end pipe opening of each telescopic pipe in the air pipe group is set in a one-to-one correspondence with the tooth dust hole of each sawtooth; the tail end pipe opening of each air pipe in the air pipe group is commonly connected to the shunt pipe 8, and the shunt pipe 8 is connected to the air source 2 through the main air pipe 3. A filter 5 and a flow controller 6 are provided in the main air pipe 3, and the flow controller 6 is used to adjust the air flow of the main air pipe 3 in real time to obtain a set noise reduction effect; Figure 1 As shown in the figure, in the cavity of the wing 1, the main air pipe 3, the filter 5 and the flow control meter 6 are fixedly arranged using the first support frame 4 and the second support frame 7; the electric push rod 10 is fixedly arranged using the third support frame 9. In this way, the entire wing noise control device is fixed in the wing cavity.

[0030] The wing noise control method based on the jet coupling sawtooth in this embodiment is to implement control of the wing noise control device based on the jet coupling sawtooth in the following manner:

[0031] Step 1. Determine the geometric dimensions of the saw teeth, including: the wing span h, the number of saw teeth arranged in parallel n, the saw tooth width w of a single saw tooth, and the tooth root spacing s between adjacent saw teeth, where h = n(w + s); wherein the saw tooth width w is 10%-40% of the wing span h, the tooth root spacing s is 200%-400% of the wing trailing edge thickness t, and the wing trailing edge thickness t is the width of the jet hole;

[0032] Step 2: Based on computational fluid dynamics, deep neural networks, and genetic algorithms, with the jet flow rate Q and sawtooth length L as design variables and the far-field noise result SPL of the wing as the objective function, a proxy model of the objective function with respect to the design variables is established, and an iterative optimization strategy is constructed that couples the optimization process with neural network prediction. Based on the optimization strategy, the parameters of the optimal jet flow rate Q1 and the optimal sawtooth length L1 when the wing noise SPL is lowest under the current flight state are obtained. Repeat step 2 to obtain the parameters of the optimal jet flow rate Q1 and the optimal sawtooth length L1 corresponding to different flight states.

[0033] Step 3: The parameters of the optimal jet flow rate Q1 and the optimal sawtooth length L1 under different flight conditions obtained in step 2 are stored in the host computer. The host computer calls the parameters of the optimal jet flow rate Q1 and the optimal sawtooth length L1 under the corresponding state according to the flight state of the aircraft. By coordinated control of the jet flow rate and sawtooth length, active and passive integrated control of wing noise based on jet-coupled sawtooth is realized.

[0034] In the specific implementation, the control process of setting the jet flow is: after the air source 2 is turned on, it continues to work at the set power to output airflow, the airflow flows through the filter 5, and then outputs the airflow through the flow control meter 6 according to the optimal jet flow Q1. The output airflow is diverted by the diverter pipe 8 and passes through the air pipe group 11 to form a jet in the tooth root hole and tooth tip hole of the sawtooth group 12, thereby weakening the turbulent pulsation in the trailing edge area and reducing noise; the control process of setting the sawtooth length is: the electric push rod 10 drives the telescopic air pipe group 14 to extend and retract, and obtains the optimal sawtooth length L1, so as to realize the destructive interference effect of the sound source generated by the sawtooth, thereby weakening the noise.

[0035] Simulation experiment:

[0036] For the NACA 0012 airfoil, the control method and device of the jet-coupled serrations of the present invention are used to construct an airfoil device with a jet-coupled trailing edge serration. The chord length is 200 mm, the span length is 20 mm, the tooth height and tooth width of the serrations are 8 mm and 4 mm, respectively. The jet holes are arranged at the tooth tips and tooth roots of the serrations. The jet holes are rectangular in shape, 1 mm long, and 0.5 mm wide.

[0037] Typical numerical simulation results are as follows Figure 4 and Figure 5The following are typical numerical simulation results of noise and energy consumption of the jet-coupled sawtooth airfoil provided by the present invention. The results show that compared with the reference airfoil, at an incoming flow velocity of 30 m / s and a corresponding Reynolds number of 4×10 5 When the jet-coupled sawtooth is used, the maximum broadband noise reduction can reach 20.5dB, and the noise reduction effect is achieved in the full frequency range of 100Hz-10000Hz. Compared with the device with only sawtooth or only jet on the trailing edge, the jet-coupled sawtooth device has a larger noise reduction amplitude and a wider noise reduction frequency range. Further research is conducted on the noise results of jetting along the entire trailing edge, that is, the entire 20mm×0.5mm area of ​​the trailing edge is jetted. To achieve a similar noise reduction effect of about 20dB, the energy momentum coefficient of the blowing is 0.6, while the control method of the jet-coupled sawtooth only requires 0.04 to achieve the same noise reduction effect, and the energy consumption is reduced by 93.3%.

[0038] The present invention effectively couples the noise reduction effects and mechanisms of active jet and passive sawtooth control methods, suppresses the noise source intensity and radiation efficiency by weakening turbulent pulsations and generating destructive interference effects, while also forming a forced convection effect between the sawtooth teeth to further reduce the self-noise of the sawtooth, thereby achieving more significant noise reduction effects across the full frequency range and under all operating conditions. Compared with a single active jet method, the present invention achieves the same noise reduction amount with lower energy consumption, significantly improving the acoustic performance of the wing airfoil while reducing energy consumption, saving engineering costs, and thereby improving economic benefits.

[0039] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A wing noise control device based on jet-coupled sawtooth, characterized by: Based on the passive control structure of wing noise formed by the sawtooth group (12) located at the trailing edge of the wing, an active control structure of wing noise is arranged in the wing cavity; the active control structure of wing noise is an active air path control structure, in which an air pipe is arranged in the wing cavity, one end of the air pipe is connected to the hollow sawtooth in the sawtooth group (12), and the other end of the air pipe is connected to an external air source, and the external air source introduces airflow into the hollow sawtooth in the sawtooth group (12) through the air pipe, and the tooth tip hole and the tooth root hole of the sawtooth are used as jet holes, and the tooth tip jet and the tooth root jet are formed in a one-to-one correspondence, thereby realizing active control of wing noise; the air pipe is arranged as an inner and outer sleeve structure with adjustable length, and is composed of a fixed pipe (13) and a telescopic pipe (14); the front end pipe opening of the fixed pipe (13) reaches the tooth root hole of the sawtooth to form the tooth root jet; the front end pipe opening of the telescopic pipe (14) reaches the tooth tip hole of the sawtooth to form the tooth tip jet; by adjusting the telescopic pipe, the air flow is controlled by the inner and outer sleeve structures; the inner and outer sleeve structures are composed of a fixed pipe (13) and a telescopic pipe (14); the front end pipe opening of the fixed pipe (13) reaches the tooth root hole of the sawtooth to form the tooth root jet; the front end pipe opening of the telescopic pipe (14) reaches the tooth tip hole of the sawtooth to form the tooth tip jet; by adjusting the telescopic pipe, the inner and outer sleeve structures are composed of a fixed pipe (13) and a telescopic pipe (14); ... The extended length of the tube (14) is used to adjust the length of the saw teeth to achieve noise control; an electric push rod (10) is provided, the electric push rod (10) is fixedly connected to the telescopic tube (14), and the extended length of the telescopic tube (14) is adjusted in real time by using the electric push rod (10) to obtain a set noise reduction effect; the air pipe is a group of air pipe groups (11) arranged in parallel, and the front end pipe openings of each fixed pipe in the air pipe group (11) are arranged in a one-to-one correspondence with the tooth root holes of each saw tooth, and the air pipe is provided in a one-to-one correspondence with the tooth root holes of each saw tooth. The front end pipe openings of each telescopic pipe in the air pipe group (11) are arranged in a one-to-one correspondence with the tooth tip holes of each saw tooth; the rear end pipe openings of each air pipe in the air pipe group (11) are commonly connected to the shunt pipe (8), and the shunt pipe (8) is connected to the air source (2) through the main air pipe (3). A filter (5) and a flow controller (6) are arranged in the main air pipe (3), and the flow controller (6) is used to adjust the air flow of the main air pipe (3) in real time to obtain a set noise reduction effect.

2. A wing noise control method based on jet-coupled sawtooth, characterized by The wing noise control device based on jet-coupled sawtooth according to claim 1 is controlled as follows: Step 1. Determine the geometric dimensions of the saw teeth, including: the wing span h, the number of parallel saw teeth n, the saw tooth width w of a single saw tooth, and the tooth root spacing s between adjacent saw teeth, where h = n(w + s); wherein the saw tooth width w is 10%-40% of the wing span h, and the tooth root spacing s is 200%-400% of the wing trailing edge thickness t, where the wing trailing edge thickness t is the width of the jet hole; Step 2: Based on computational fluid dynamics, deep neural networks, and genetic algorithms, with the jet flow rate Q and sawtooth length L as design variables and the far-field noise result SPL of the wing as the objective function, a proxy model of the objective function with respect to the design variables is established, and an iterative optimization strategy is constructed that couples the optimization process with neural network prediction. Based on the optimization strategy, the parameters of the optimal jet flow rate Q1 and the optimal sawtooth length L1 when the wing noise SPL is lowest under the current flight state are obtained. Repeat step 2 to obtain the parameters of the optimal jet flow rate Q1 and the optimal sawtooth length L1 corresponding to different flight states. Step 3: The parameters of the optimal jet flow rate Q1 and the optimal sawtooth length L1 under different flight conditions obtained in step 2 are stored in the host computer. The host computer calls the parameters of the optimal jet flow rate Q1 and the optimal sawtooth length L1 under the corresponding state according to the flight state of the aircraft. By coordinated control of the jet flow rate and sawtooth length, active and passive integrated control of wing noise based on jet-coupled sawtooth is realized.

3. The wing noise control method based on jet-coupled sawtooth according to claim 2 is characterized by: The control process of the jet flow is as follows: after the air source (2) is turned on, the air flow is continuously output according to the set power, the air flow flows through the filter (5), and then the air flow is output according to the optimal jet flow Q1 through the flow control meter (6). The output air flow is diverted by the diverter pipe (8) and passes through the air pipe group (11) to form a jet in the tooth root hole and the tooth tip hole of the sawtooth group (12), thereby weakening the turbulent pulsation in the trailing edge area and thus reducing noise; the control process of the sawtooth length is as follows: the telescopic tube (14) is driven to extend and retract by the electric push rod (10) to obtain the optimal sawtooth length L1, so as to achieve the destructive interference effect of the sound source generated by the sawtooth, thereby weakening the noise.

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