37 results about "Propeller noise" patented technology

The invention discloses a method, a device, a medium and a program for forecasting noise of a water surface ship propeller based on excitation source reconstruction. The method comprises the following steps: firstly, determining vibration sensing point location distribution and sound field assessment point positions; determining the arrangement and size of a reconstruction source; obtaining vibration and sound transfer functions from the reconstruction source to the sound field assessment point, and numbering the functions in sequence; according to a transfer function invariance principle, establishing a propeller noise forecasting method based on a reconstructed excitation source; rapid prediction of the structural noise of the propeller shaft ship under multiple reconstruction sources is realized; the direct sound production coherence of the propeller is judged, if the direct sound production coherence is strong coherence, correction continues to be carried out to obtain vibration sound transfer functions from the reconstruction source to the sound field assessment point, and numbering is carried out in sequence; if the signal is weak coherence, a direct sound production noise source model is established based on a sound-sound transfer function, radiation noise under direct sound production of the propeller is obtained through calculation, and prediction of the propeller noise considering direct sound production is achieved based on the vector superposition principle. The method is suitable for ship thruster shafting vibration monitoring and thruster noise rapid forecasting and evaluation.

The invention discloses a partial discharge detection method, device and equipment and a medium, and relates to the technical field of automatic control, and the method comprises the steps: obtaining the configuration information of an unmanned plane and a historical propeller noise signal; generating a real-time noise reduction signal according to the configuration information and the historical propeller noise signal; by playing sound corresponding to the real-time noise reduction signal, acquiring a real-time equipment sound signal of the to-be-detected equipment, wherein the real-time equipment sound signal counteracts the propeller noise signal; and according to the real-time equipment sound signal offsetting the propeller noise signal, performing partial discharge detection on the to-be-detected equipment to obtain a partial discharge detection result of the to-be-detected equipment. According to the embodiment of the invention, the noise of the equipment sound signal can be reduced through the generated real-time noise reduction signal, and compared with the prior art, the propeller noise can be accurately removed from the equipment sound signal, so that the influence of the propeller noise of the unmanned aerial vehicle on partial discharge detection is avoided, and the accuracy of partial discharge detection is improved.

The invention discloses a propeller noise rapid forecasting method and system based on a PSO-Elman neural network, and belongs to the field of propeller noise forecasting, and the method comprises the steps: collecting ship propeller noise data and propeller noise influence factor data, carrying out the preprocessing, combing the data correlation, constructing a sample set, and carrying out the prediction of the propeller noise; an Elman neural network model is established and optimized by adopting a particle swarm optimization algorithm, a sample set is input into the model for training and verification, and an optimal PSO-Elman neural network model is obtained and is applied to forecast the propeller noise of a certain ship. According to the method, the Elman neural network is combined with the particle swarm optimization algorithm, a large amount of data can be efficiently processed, rapid calculation of noise forecasting is achieved, meanwhile, propeller noise forecasting requirements under different environments and parameter conditions can be met, the accuracy of noise forecasting is improved, self-adaptive optimization of a noise forecasting model is achieved, and the noise forecasting accuracy is improved. And the accuracy and the stability of the forecasting result are continuously improved.

The invention discloses an unmanned aerial vehicle noise elimination method and device for cross-medium direct acoustic communication, and the method comprises the steps: carrying out the sampling of a known detection signal and a receiving signal, obtaining a frequency domain expression, calculating a cross-medium sound pressure transmission function, and extracting amplitude response, phase response and group delay; based on a normalization ratio and local maximum detection method, identifying a center frequency set of unmanned aerial vehicle propeller noise; the notch depth, bandwidth, frequency compensation and phase compensation are determined by combining channel characteristic parameters, and a cascade notch filter is constructed; and inputting the channel characteristic parameters into the deep learning model, outputting a filter parameter correction amount, realizing dynamic updating of the filter, obtaining the filter capable of suppressing noise, and further obtaining a denoised communication signal. According to the invention, precise detection of propeller noise frequency and multi-dimensional adaptive adjustment of filter parameters can be realized.

The invention provides a seismic imaging method and device based on propeller noise, a medium and equipment, and relates to the technical field of marine seismic exploration. The method comprises the following steps: firstly, acquiring seismic data generated by a propeller of a ship in the process that the ship travels according to a preset route, and extracting propeller noise data from the seismic data; then, calculating a sound wave field generated by the propeller based on the propeller noise data, and performing seismic imaging processing based on the sound wave field to obtain a seismic superposition profile map; therefore, marine seismic exploration is carried out by taking the independent ship propeller as a seismic source, and seismic imaging processing is carried out by effectively utilizing noise data generated by the propeller, so that the cost of marine seismic exploration is reduced, and the resolution of seismic imaging is improved.

The invention discloses an analysis and prediction method for high-frequency noise of a pod propeller, and the method comprises the following steps: S1, obtaining flow field original data and corresponding high-frequency noise monitoring data of the pod propeller in a working state, and carrying out the preprocessing; and S2, constructing a flow field-noise coupling analysis framework based on the separation vortex model, and setting a time step length and a calculation frequency matched with actual working conditions. The invention relates to the technical field of ship propeller noise analysis and prediction. According to the pod propulsor high-frequency noise analysis and prediction method, flow field vortex structure characteristics can be captured by constructing a flow field-noise coupling analysis framework and processing the preprocessed flow field data, and the contribution degree of each vortex unit to the high-frequency noise is accurately calculated based on a vortex structure and noise generation correlation mechanism, so that the high-frequency noise analysis and prediction method is provided for the high-frequency noise analysis and prediction of the pod propulsor. The vortex units leading the noise source are screened, dynamic positioning of the high-frequency noise source is achieved by combining the space-time position information of the vortex units, and the source of noise generation can be deeply known.

The invention discloses a submarine with a novel structure. High-pressure steam generated by nuclear energy is used as power to push a cylinder piston in the high-pressure cylinder to reciprocate. The air cylinder piston drives the water cylinder piston to reciprocate, and seawater in the water cylinder is pressurized and pressed into the high-pressure water storage tank. The seawater in the high-pressure water storage tank is distributed to the regional water supply pipeline through the high-pressure water supply main pipeline, and finally the high-pressure seawater is supplied to the high-pressure seawater spraying module. The high-pressure seawater spraying modules are distributed on the surface of the submarine and connected through butt joints. The flat capillary nozzle sprays seawater to the tail of the submarine at a high speed, the surface of the submarine is covered with a layer of water film flowing backwards at a high speed, the water film is used for reducing the resistance of the seawater, and the water film and the recoil force of surrounding seawater are used for providing advancing power. Under the same pressure, the smaller the nozzle is, the higher the water flow speed is, and the overall backward water spraying speed is increased through the capillary nozzle. Rotary power is not needed, complex steam turbines and propellers are omitted, noise is low, and concealment is high.

The invention provides a large and medium-sized water surface ship radiation noise generation and control method, system and device covering a scale effect, and a storage medium, and belongs to the field of large and medium-sized water surface ship radiation noise prediction and analysis. The difference of contribution degrees of machinery, hydrodynamic force and propeller noise to underwater radiation noise in different navigation states is considered, a multi-modal noise separation method is adopted to separate coupling components, and a ship underwater radiation noise source is simplified into a noise source model along a ship body; a ship scale effect analysis and multi-resolution time-frequency analysis technology is introduced, and a generation mechanism of ship radiation noise is simplified into underwater radiation noise caused by shell vibration caused by the fact that a plurality of distributed low-frequency loads act on a ship structure; large and medium water surface ship radiation noise passing characteristic rules are disclosed, and a ship navigation state underwater radiation noise simulation theoretical model is established. According to the method, an effective means is provided for generation and control of underwater noise of the ship, and optimization of ship design and reduction of underwater radiation noise are facilitated.

The invention discloses an underwater propeller blade number identification method based on shaft blade frequency double harmonic search. The method comprises the following steps: (1) collecting an underwater propeller noise signal; (2) calculating the acquired noise signal by using a rapid spectrum-following correlation algorithm to obtain a cyclic spectrum correlation; (3) normalizing the obtained cyclic spectrum correlation to obtain cyclic spectrum coherence, and further constructing an enhanced envelope spectrum by integral average; (4) preprocessing the enhanced envelope spectrum, extracting a line spectrum, and then inputting conditions to carry out peak value search to obtain an alternative axis frequency; (5) inputting detection parameters to construct a search space; and for the combination of each alternative shaft frequency and the blade number, calculating a peak index and obtaining a combination probability table, and finally determining the blade number. The method can reliably extract the propeller blade number characteristics in a complex noise environment, improves the recognition precision, and has important practical application value for target recognition and classification.

This invention relates to the field of passive underwater target identification technology, and in particular to a propeller noise cyclic coherent demodulation method based on an improved real-number genetic algorithm. Based on cyclic stationarity analysis theory, an optimal coherent weighted quadratic envelope spectrum is constructed by replacing the fixed integration frequency band with a weighting function, and an adaptive detection threshold is constructed based on the false alarm probability. The observed spectrum is modeled as the sum of harmonics and noise, and a sparse non-negative optimization problem is solved to extract the harmonics. Using the total harmonic intensity of the envelope spectrum as the cost function, an improved real-number genetic algorithm is used to optimize and search for the optimal weighting coefficient vector. The demodulated spectrum is obtained by coherently weighting and integrating the normalized cyclic modulation spectrum. This invention achieves autonomous allocation of weighting coefficients and adaptive selection of demodulation frequency bands, effectively improving the signal-to-noise ratio gain of cyclic demodulation, and is applicable to passive target identification in data backtracking and review systems.

This invention relates to a method and system for locating coaxial counter-rotating sound sources in rotorcraft, belonging to the technical field of sound source identification methods. It includes: processing the sound pressure signal of the moving sound source using continuous wavelet transform to obtain time-frequency domain variation results; performing Doppler effect correction based on experimental conditions; estimating the spatial location and relative intensity of the noise source using a cross-spectral matrix and weight vector; and performing phase-locked analysis of the rotor noise source intensity using a phase-locked averaging method. This invention differs from traditional time-domain delay superposition algorithms and frequency-domain cross-correlation spectrum methods. It can image unsteady sound sources using time-frequency domain characteristics, solving the acoustic imaging problem of counter-rotating propeller noise and possessing potential applications in the rotorcraft industry.

The invention provides a blade, a propeller, a power propelling device and a ship, and relates to the technical field of propeller noise control, and the blade comprises a blade root, a blade body and a blade tip which are connected in sequence; the blade body is provided with a first pressure surface and a first suction surface which are oppositely arranged, and in the rotating process of the paddle, fluid can flow from the position of the first pressure surface to the position of the first suction surface; at least a portion of the blade tip is curved toward the first pressure surface. According to the technical scheme, at least one part of the blade tip is bent towards the first pressure surface of the blade body, so that the design mode is beneficial to structural optimization of the blade tip, vortex-induced resonance can be inhibited to a great extent, and noise pollution is reduced.

According to the ducted propeller with the bionic front edge nodule blade structure and the manufacturing method, starting from two-dimensional type value points of propeller blades, chord lengths of several groups of cross sections are changed by modifying two-dimensional type value points of related cross sections, and therefore the shape of the front edge of the blade is finally changed; the invention particularly provides the ducted propeller with the bionic front edge nodule blade configuration, which is obtained according to the manufacturing method of the ducted propeller with the bionic front edge nodule blade configuration. The technical problems existing in the aspects of shape design optimization, fluid performance optimization design and propeller noise control of a ducted propeller and a conventional propeller in the prior art are solved.

The invention relates to a double-engine propeller noise prediction and optimization method based on an analytical method, and belongs to the field of aviation acoustics. The method disclosed by the invention comprises a noise prediction method and a noise optimization method, the noise prediction method establishes a noise prediction model based on an improved propeller characteristic theory, and the noise optimization method comprises the following steps: S1, establishing a noise objective function based on the noise prediction model, solving a first-order partial derivative and a Hessian matrix of the noise objective function, and obtaining a first-order partial derivative of the noise objective function; the method comprises the steps of S1, providing a noise target function, S2, providing a new Euler formula transformation method, and converting a triangular polynomial corresponding to a first-order partial derivative of the noise target function into a zero-equivalent algebraic polynomial, S3, analyzing and solving the zero point of the algebraic polynomial by using a Fourier-Frobenius matrix method, and S4, realizing synchronous maximum noise reduction control. According to the method, an improved propeller characteristic value theory and a Hessian + Fourier-Frobenius matrix method are used for rapidly and accurately solving an analytical solution of the minimum noise, and the method is combined with synchronous control, so that the limitation on the time and precision of predicting the minimum noise is overcome.

The invention belongs to the technical field of artificial baits, and discloses a propeller type noise crossed double-hook bait which comprises a mounting shaft, a propeller assembly and double hooks arranged in the propeller assembly in a crossed mode, and the mounting shaft is movably arranged on the upper portion of the propeller assembly; the mounting shaft comprises a first mounting ring; the propeller assemblies include a first propeller assembly and a second propeller assembly. Through the arrangement of the mounting shaft and the propeller assembly, the whole double-hook bait can rotate under the action of water flow in the using process, then noise is generated to better attract fish schools to approach, and the fish catching probability is effectively increased; compared with an existing arrangement mode that a single hook or double hooks are arranged side by side or two hooks are tied on one line, the double-hook cross arrangement has the advantages that grass hanging can be prevented, and the fish catching stability is improved.

This invention relates to the field of ship design and propulsion technology, and discloses a catamaran and its control method. The catamaran includes a hull, with the width direction defined as the direction perpendicular to the catamaran's direction of travel in a horizontal plane. The hull includes a first hull and a second hull arranged symmetrically and at intervals along the width direction, with a channel formed between the first and second hulls along the width direction. It also includes a propulsion assembly disposed in the channel, comprising at least one fin adapted to oscillate to drive the catamaran's movement. This invention solves the problems of high propeller noise, cavitation, and difficulty in towing loads in related technologies for catamarans.

The application discloses a kind of analysis and prediction methods of high-frequency noise of pod propeller, comprising the following steps: S1, obtain the flow field original data and corresponding high-frequency noise monitoring data under the working state of pod propeller, and pre-process;S2, based on the separated vortex model, construct flow field-noise coupling analysis framework, set the time step and calculation frequency matched with actual working condition, the present application relates to ship propeller noise analysis and prediction technical field.The analysis and prediction method of high-frequency noise of the pod propeller, by constructing flow field-noise coupling analysis framework, the pre-processed flow field data are processed, the vortex structure characteristics of flow field can be captured, and based on the correlation mechanism of vortex structure and noise generation, the contribution of each vortex unit to high-frequency noise is accurately calculated, the vortex unit of dominant noise source is screened, and the dynamic positioning of high-frequency noise source is realized in combination with its space-time position information, which helps to understand the root of noise generation.

The invention discloses a propeller noise reduction design method of an eVTOL aircraft and a related device. The method comprises the steps that according to spatial design parameter data, a plurality of spatial design parameter combinations meeting the design requirements of the total lift force requirement and the structural strength requirement of the eVTOL aircraft are obtained; performing distributed propeller system-level noise simulation processing on the propeller design corresponding to each spatial design parameter combination to obtain a system-level noise simulation result corresponding to each spatial design parameter combination; obtaining a first space design parameter combination with the lowest total noise according to a system-level noise simulation result; and performing noise reduction design processing on the propeller in the first space design parameter combination to obtain a propeller noise reduction design result. In the embodiment of the invention, the rapid reconstruction of the full-aircraft noise field is realized, compared with the complete modeling, the calculation amount is obviously reduced, and the time period of the distributed propeller multi-parameter design optimization is shortened.

The utility model relates to a device for reducing submarine propeller noise, submarine hydrodynamic wake flow and submarine thermal wake flow, which comprises a submarine fairing, a support steel beam, an electric control cabinet, a cable connected with a submarine control center, a hydraulic station, a hydraulic pipeline and signal line, a support beam anechoic tile, a connector anechoic tile, a connector bolt and a submarine center control platform. The supporting steel beam is welded to the submarine, the hydraulic station and the electric control cabinet are arranged in the submarine, the fairing is connected with the supporting steel beam through the connector bolts, a cable, a hydraulic pipeline and a signal line which are connected with a submarine control center are connected with the hydraulic station and the electric control cabinet through the interior of the supporting steel beam, and the supporting beam anechoic tile is installed on the supporting beam. The connecting body anechoic tiles are installed at the connecting positions of the connecting body bolts and the supporting steel beams, the flow guide cover is composed of a front body, a middle body, a tail body, a front body foam breaking ring body, a middle body foam breaking ring body, a tail body foam breaking ring body, a hydraulic cylinder assembly, a rotating assembly, a sound absorption wedge and accessories, and a horn mouth structure is arranged at a tail outlet.

The invention belongs to the technical field of vertical take-off and landing aircrafts, and particularly relates to a noise-controllable vertical take-off and landing aircraft propeller design method and an implementation device. The design method comprises the steps of selecting a blade spanwise key position and determining a basic airfoil profile, optimizing the airfoil profile at the key position, constructing a preliminary propeller configuration, exploring the influence of chord length, negative torque and blade number on noise, determining the basic configuration and optimization range of the propeller, optimizing the aerodynamic performance of the propeller and the like. According to the method, starting from airfoil optimization of key positions of blades, the influence of chord length, a negative torsion value and the number of the blades on propeller noise is gradually explored, a propeller basic configuration and an optimization range which are acceptable in noise are determined, multi-target pneumatic optimization is carried out on the basis, the pneumatic efficiency of the propeller is improved, the noise level is reduced, and the propeller noise is reduced. The trial and error cost and time are reduced, a high-performance and low-noise propeller design scheme can be provided for the vertical take-off and landing aircraft, and the application requirements of the vertical take-off and landing aircraft in complex environments such as urban air traffic are met.

The invention discloses a vertical take-off and landing aircraft lift propeller noise reduction method and system, and the method comprises the steps: collecting a noise signal generated by a composite wing eVTOL lift propeller, the current flight state data of an aircraft, and the external environment data, and carrying out the preprocessing of the collected data; extracting spatial features of multi-source noise data on multiple scales by using a CNN convolutional neural network, capturing time sequence features of noise in combination with an LSTM long short-term memory network, and performing weighted fusion on the spatial features and the time sequence features; establishing a hybrid model, optimizing parameters of the hybrid model by using a multi-objective optimization algorithm, inputting the fused noise data into the optimized hybrid model, and generating an optimal noise reduction strategy; and generating a control instruction according to the optimal noise reduction strategy, and controlling the rotation speed and the blade angle of the composite wing eVTOL lift propeller according to the control instruction. Multi-dimensional analysis and noise reduction of propeller noise are achieved, and the noise reduction effect is remarkably improved.

The application provides a paddle, a propeller, a power propulsion device and a ship, and relates to the technical field of propeller noise control, wherein the paddle comprises a blade root, a blade body and a blade tip which are sequentially connected; the blade body has a first pressure surface and a first suction surface which are oppositely arranged, in the process of rotation of the paddle, fluid can flow from the position of the first pressure surface to the position of the first suction surface; at least a part of the blade tip is curved towards the first pressure surface. In the technical scheme of the application, at least a part of the blade tip is curved towards the first pressure surface of the blade body, and this design is beneficial to the structural optimization of the blade tip, can greatly inhibit vortex-induced resonance and reduce noise pollution.

A method for actively controlling the propeller noise of an underwater vehicle relates to the field of underwater vehicle noise reduction. The method for actively controlling the propeller noise of an underwater vehicle comprises the following steps: analyzing the sound field of the propeller noise source of the underwater vehicle to determine the frequency range to be controlled; determining the specifications and dimensions of the transducer according to the frequency range to be controlled; setting the propeller position of the propeller of the underwater vehicle as the origin, and determining the placement position and number of the transducer and the hydroacoustic signal sensor through simulation optimization according to the structural characteristics of the stern of the underwater vehicle and the size of the selected transducer; arranging the transducer and the hydroacoustic signal sensor at the stern of the underwater vehicle according to the determined number and position, and detecting the far-field sound source control effect of the underwater vehicle to determine the active noise control effect. The method for actively controlling the propeller noise of the underwater vehicle can effectively control the low-frequency line spectrum noise of the propeller of the underwater vehicle.

The invention discloses an amphibious vehicle propeller noise control system and method based on PID adjustment, and belongs to the technical field of automobile control, and the amphibious vehicle propeller noise control system based on PID adjustment combines a PID adjustment algorithm with an active noise reduction algorithm, monitors an external environment, adjusts dynamic variable parameters, and improves the noise reduction performance of the amphibious vehicle propeller. The control parameters are converted into propeller control parameters and active noise reduction module control parameters to control noise reduction parameters of an impeller adjusting mechanism and a microphone, and finally noise reduction signals processed through an algorithm are used for sending out reverse sound waves through a loudspeaker to reduce noise in a vehicle.

The invention belongs to the field of signal processing, and particularly relates to a noise suppression method based on UUV motion under a complex noise background. The invention aims to solve the problem that the existing noise processing method is low in efficiency. According to the noise suppression method based on UUV motion under the complex noise background, the sound source positions and arrays of propeller noise and vibration noise are relatively unchanged in the steering period of the UUV, and the incident angle of a signal changes along with the course angle of a platform. If the environmental noise is kept stable, the noise shows the characteristic of being stable and unchanged during steering, and the signal shows the characteristic of changing along with the course angle. According to the method, the difference between the signal covariance and the noise covariance is utilized, changing signals are filtered out in the frequency domain, and the noise covariance is estimated. And then noise suppression is carried out by using the estimated noise covariance, so that detection in a complex noise environment is further realized, and the problem of low efficiency of an existing noise processing method is solved.

The invention discloses an underwater vehicle propeller noise rapid forecasting method and device based on excitation source reconstruction, a medium and a program, and belongs to the technical field of noise forecasting. According to the method, based on basic theories such as invariance of a vibration transfer function relation and a sound wave energy superposition principle, a vibration source reconstruction technology is introduced into propeller noise forecasting, and vibration responses obtained through measurement of a limited number of vibration sensors on a propeller stern structure are used as input; reconstructing excitation source matching structure surface vibration based on a vibration transfer function, and solving radiation noise caused by propeller shaft boat structure vibration generated by the structure vibration through the reconstructed excitation source; and establishing a rapid prediction method for direct sound production of the propeller under different coherences, and realizing rapid prediction and evaluation of propeller shaft boat coupling noise and direct sound production propeller noise based on an energy superposition principle. The method is suitable for ship real-time monitoring of propeller shafting vibration and radiation noise.

This invention discloses a method for simulating radiated noise signals from a counter-rotating propeller target, comprising: First, setting basic parameters of the counter-rotating propeller target, including simulation time, simulation harmonics, and signal-to-noise ratio (SNR). Second, setting signal parameters of the counter-rotating propeller target under stable navigation conditions, including noise fundamental frequency and frequency fluctuation variance, and setting signal parameters of the counter-rotating propeller target under maneuvering conditions, including maneuvering time and fundamental frequency increment. Third, generating signal frequency curves based on the signal parameters of the counter-rotating propeller target under stable navigation and maneuvering conditions. Fourth, calculating the signal phase point by point based on the counter-rotating propeller target signal frequency curves to generate a simulated counter-rotating propeller noise line spectrum signal. Fifth, adding noise according to the SNR and summing the results to generate a simulated counter-rotating propeller target noise signal. This method can accurately describe the time-varying frequency characteristics under different conditions, ensuring phase continuity and time-frequency consistency.

The invention discloses a method, a device, a medium and a program for forecasting noise of a water surface ship propeller based on excitation source reconstruction. The method comprises the following steps: firstly, determining vibration sensing point location distribution and sound field assessment point positions; determining the arrangement and size of a reconstruction source; obtaining vibration and sound transfer functions from the reconstruction source to the sound field assessment point, and numbering the functions in sequence; according to a transfer function invariance principle, establishing a propeller noise forecasting method based on a reconstructed excitation source; rapid prediction of the structural noise of the propeller shaft ship under multiple reconstruction sources is realized; the direct sound production coherence of the propeller is judged, if the direct sound production coherence is strong coherence, correction continues to be carried out to obtain vibration sound transfer functions from the reconstruction source to the sound field assessment point, and numbering is carried out in sequence; if the signal is weak coherence, a direct sound production noise source model is established based on a sound-sound transfer function, radiation noise under direct sound production of the propeller is obtained through calculation, and prediction of the propeller noise considering direct sound production is achieved based on the vector superposition principle. The method is suitable for ship thruster shafting vibration monitoring and thruster noise rapid forecasting and evaluation.

This invention provides a method and system for mathematical noise cancellation of propellers based on FFT. It involves processing the time-domain signal data of propeller noise using FFT to obtain a frequency-domain signal. This frequency-domain signal is then plotted as a spectrum with frequency on the horizontal axis and sound pressure level on the vertical axis. The spectrum is used to determine whether a singing tone exists within the frequency-domain signal of the propeller noise. If a singing tone is present, it is categorized into three types based on its influence range and position within the full frequency band of the spectrum: Type I, Type II, and Type III. Different judgment and calculation methods are then used to eliminate the singing tone in each of these three types, thus completing the noise cancellation of the propeller. This invention does not require time or financial costs to modify the propeller model, nor does it require changing the rated operating conditions in the original experimental plan.

This invention belongs to the field of vertical takeoff and landing (VTOL) aircraft technology, specifically relating to a noise-controllable VTOL aircraft propeller design method and implementation device. The design method includes steps such as selecting key positions in the blade spanwise direction and determining the basic airfoil, optimizing the airfoil at the key positions, constructing a preliminary propeller configuration, investigating the influence of chord length, negative torque, and blade number on noise, determining the basic propeller configuration and optimization range, and optimizing the propeller aerodynamic performance. This method starts with optimizing the airfoil at the key positions of the blade, gradually investigating the influence of chord length, negative torque, and blade number on propeller noise, determining the basic propeller configuration and optimization range with acceptable noise, and performing multi-objective aerodynamic optimization based on this. This improves the aerodynamic efficiency of the propeller, reduces the noise level, and reduces trial and error costs and time. It can provide a high-performance, low-noise propeller design scheme for VTOL aircraft, meeting their application needs in complex environments such as urban air traffic.