14 results about "Aircraft noise" patented technology

This invention discloses a superstructure design method for suppressing noise loads in aircraft under high-speed environments, relating to the field of aircraft design. The method includes: obtaining characteristic noise frequencies through simulation using a typical cavity model; introducing various designable structures such as micro-perforated plates, Helmholtz resonators, and porous materials to construct acoustic superstructures capable of suppressing or phase-shifting noise loads at these frequencies; and solidifying the acoustic superstructure assembly style through ground tests or wind tunnel tests to facilitate its physical realization. This invention addresses the problem that commonly used cavity noise reduction methods cannot be applied to high-speed cavity structures by designing and optimizing various acoustic superstructure assemblies capable of suppressing or phase-shifting noise loads to achieve optimized suppression of noise loads in aircraft cavities under high-speed environments.

The invention discloses an active noise reduction method, device and equipment for a take-off and landing point of a hovercar and a program product. The method comprises the steps that real-time noise signals and real-time environment parameters around a take-off and landing platform and real-time attitude parameters of the hovercar are acquired; performing propagation attenuation compensation on the real-time noise signal to obtain a corrected noise signal; matching in the model noise model library to obtain a corresponding rotor noise reference spectrum, an airflow noise reference spectrum and a power system noise reference spectrum; performing feature analysis on the corrected noise signal to obtain a rotor noise component, an airflow noise component and a power system noise component; predicting the change trend of the noise component through an adaptive filtering algorithm to obtain a predicted noise signal, and predicting the next airspace position of the hovercar according to the real-time attitude parameters; and generating an offset sound wave signal according to the predicted noise signal, and transmitting the offset sound wave signal to a next airspace position. The method realizes active noise reduction of the take-off and landing point of the hovercar, and can be applied to the technical field of hovercars.

The embodiment of the invention discloses an aircraft noise prediction method and device, electronic equipment and a storage medium, and relates to the technical field of aircraft aeroacoustics and computational fluid mechanics, and the method comprises the steps: obtaining a core parameter, calculating a load noise sound pressure level through a formula, and obtaining a load noise sound pressure level; calculating a thickness noise sound pressure level based on Hawkins and Lowson methods to construct a low-precision data field; sampling points are screened by adopting Latin hypercube sampling, the sampling points are calculated by combining an unsteady flow field with a sound integration method to obtain a high-precision sound pressure level, and high-precision data are obtained through flow field solution; calculating to obtain a system error of the empirical formula, and obtaining a parameter-error mapping table according to the parameter combination of the sampling points and the system error; and constructing an error prediction model by adopting a Gaussian process regression model and training, inputting parameters of a to-be-predicted point into the model to obtain an error compensation prediction value, and combining with the low-precision sound pressure level to obtain a prediction result. The problem that precision and efficiency cannot be achieved at the same time in the prior art is solved.

Vertical take-off and landing (VTOL) aircraft can provide opportunities to incorporate aerial transportation into transportation networks for cities and metropolitan areas. However, VTOL aircraft may be noisy. To accommodate this, the aircraft may utilize onboard sensors, offboard sensing, network, and predictive temporal data for noise signature mitigation. By building a composite understanding of real data offboard the aircraft, the aircraft can make adjustments to the way it is flying and verify this against a predicted noise signature (via computational methods) to reduce environmental impact. This might be realized via a change in translative speed, propeller speed, or choices in propulsor usage (e.g., a quiet propulsor vs. a high thrust, noisier propulsor). These noise mitigation actions may also be decided at the network level rather than the vehicle level to balance concerns across a city and relieve computing constraints on the aircraft.

The invention relates to the technical field of aircraft noise reduction, in particular to a duct noise reduction method and device based on electric vertical take-off and landing design, and the method comprises the steps: determining target noise to be subjected to noise reduction of an eVTOL aircraft duct; based on the target to-be-denoised noise and a preset resonant frequency expression of a Helmholtz resonator, target Helmholtz resonator units meeting different frequency requirements are obtained, and corresponding resonant noise reduction unit parameters are determined according to the target Helmholtz resonator units; based on the resonance noise reduction unit parameters, determining a distribution proportion corresponding to the target Helmholtz resonator unit so as to distribute the target Helmholtz resonator unit in an acoustic liner of an eVTOL aircraft duct, and constructing a target sound absorber; and noise reduction is performed on blade passing noise and tubular cavity resonance noise generated in the operation process of the eVTOL aircraft based on the target sound absorber. Therefore, the problems of serious noise pollution and the like caused by the eVTOL aircraft are solved.

The invention provides a stiffened plate sound insulation optimization method and device, and belongs to the technical field of aircraft noise control, and the method comprises the steps: obtaining the structure parameters of a stiffened plate, and determining the sound insulation analysis frequency of the stiffened plate; constructing a structural finite element model of the stiffened plate based on the structural parameters, determining the mesh size of the finite element model, and performing acoustic mesh division on the structural finite element model of the stiffened plate according to the mesh size; a plurality of plane wave sound sources are arranged around the structural finite element model of the stiffened plate, reverberation-noise elimination structures are arranged between the structural finite element model of the stiffened plate and the plane wave sound sources, an acoustic-solid coupling finite element matrix equation of the stiffened plate is established, and a reverberation-noise elimination sound insulation analysis model is obtained; determining a sound reduction index optimization range of the stiffened plate, and building a sound reduction index optimization objective function of the stiffened plate; sound-vibration coupling sound insulation analysis of the stiffened plate is carried out based on the reverberation-noise elimination sound insulation analysis model, meanwhile, iteration is carried out on the stiffened plate sound insulation index optimization objective function, and finally sound insulation index optimization of the stiffened wall plate is achieved.

The application discloses an aircraft APU air inlet sound source simulation device and a simulation method, and belongs to the technical field of aircraft noise testing. The aircraft APU air inlet sound source simulation device comprises a loudspeaker, a waveguide tube, a fixed connection assembly, a measurement microphone and an electrical and signal control assembly, the measurement microphone and the waveguide tube are fixed on the fixed connection assembly, the loudspeaker is fixed on the waveguide tube, one end of the electrical and signal control assembly is connected to the measurement microphone, and the other end of the electrical and signal control assembly is connected to the loudspeaker, the aircraft APU air inlet sound source simulation method comprises a method for simulating a sound mode sound source and a method for simulating wideband noise / single-frequency noise. The application is aimed at a sound mode generating device in a rectangular pipe of an APU air inlet, and the equation group formed by a response function of a control method part has great innovation.

The invention provides an acoustic metamaterial suitable for a leading edge slat, a design method and the slat, and belongs to the field of aircraft noise reduction. The acoustic metamaterial comprises a plurality of acoustic metamaterial subunits, and each subunit is composed of a micro-perforated plate and a cavity. And at least one of the plurality of subunits is linear and the internal channel of the cavity is linear, and at least one of the plurality of subunits is curved and the internal channel of the cavity is curved. The linear and curved subunits form a conformal unitary structure by an adaptive arrangement including profile adaptation within the airfoil profile and location distribution and combination within a profile perpendicular to the airfoil profile and along the leading and trailing edges. According to the invention, extremely limited space in the slat is utilized to the maximum extent through conformal design, a sound wave propagation path is prolonged at a sub-wavelength scale through linear and curved cavity channels, efficient low-frequency sound absorption is realized, broadband noise is covered through combination of multiple subunits, and the problem of insufficient low-frequency sound absorption in a slat space in a traditional scheme is effectively solved.

The invention relates to an aircraft noise source positioning method and device, a medium and application, and the method comprises the steps: S1, grouping M microphone arrays to form m sub-arrays, M and m being integers; s2, aiming at each sub-array, solving sound source space distribution to obtain a sound source positioning result of each sub-array; and S3, multiplying the m sound source localization results by the m-power root of the product to obtain a result as a final sound source localization result. The method provided by the invention can be suitable for more complex and more practical microphone array distribution, and a sound source positioning result with higher precision can be obtained.

The invention discloses an aircraft noise isoline generation method based on QAR data. The method comprises the following steps: S1, collecting and processing flight QAR data; s2, data preprocessing; s3, reconstructing a flight path; s4, calculating a thrust value; s5, correcting the noise source intensity through the correction model in combination with the airplane NDP curve and the data table, and constructing a noise source intensity model; and S6, constructing a noise model, carrying out gridding, calculating a noise value of each grid unit, carrying out correction and accumulation calculation on the noise values, and then drawing an aviation noise isoline. Compared with the prior art, the method can accurately simulate the noise levels of different flight stages based on the noise isoline calculation of the QAR data in combination with the actual operation parameters of the airplane, and has the advantages of being high in accuracy and high in reliability. A built-in noise prediction model is utilized, a space gridding technology is combined, noise intensity distribution is visually displayed in a contour line form, a noise contour line can be dynamically updated, and noise change conditions in different time periods can be reflected.

The invention discloses a supersonic aircraft noise audible visualization method and device, and relates to the field of aviation acoustics. Firstly, supersonic aircraft engine parameters are obtained; and calculating noise data generated by different parts of the supersonic aircraft engine through a data prediction algorithm. Secondly, carrying out superposition and dynamic correction on noise data of different parts; and constructing a three-dimensional model of the aircraft and the flight scene. And finally, superposing the noise test virtual scene with a real scene, testing the supersonic aircraft engine, and displaying a test result. According to the method, on the basis of the mixed reality technology, an approval person and a designer are allowed to experience personally and evaluate the noise influence in a virtual environment, so that whether the design meets regulatory requirements or not is more effectively verified, abstract noise data are converted into audible and visual immersive experience, complex noise prediction data are displayed in a real-time and three-dimensional mode, and the method is more practical. And a designer can intuitively find the noise problem.

The invention provides an aircraft ground acoustic characteristic field measurement method, and belongs to the technical field of aircraft noise control, and the method comprises the steps: determining an aircraft test piece type used for ground acoustic characteristic measurement, the aircraft test piece type being a full-size aircraft or an aircraft cabin; aircraft acoustic characteristic measurement is carried out on the test piece, and the aircraft acoustic characteristic measurement comprises static sound insulation characteristic measurement, cabin reverberation time measurement, engine or power device driving measurement, airborne equipment noise measurement and sound vibration correlation measurement; and obtaining the static sound insulation characteristic of the airframe structure, the reverberation time of a cabin, the surface noise characteristic of the aircraft, the engine noise directivity, the engine noise source characteristic, the attenuation characteristic of the noise radiation value of airborne equipment along with the distance in different directions and the coupling characteristic of noise and vibration according to the measurement result of the acoustic characteristic of the aircraft. According to the method, the acoustic characteristics of the actual installation state of the airborne equipment are measured by using the full-size aircraft or the aircraft cabin, and the effectiveness of aircraft noise control measures can be verified.

The invention provides an airport aircraft noise prediction method fusing an ellipsoid and a nonlinear function, relates to the technical field of environment monitoring and noise control, and solves the problem that the existing method is difficult to accurately describe the limitation of the propagation process of noise in a real dynamic environment. The method comprises the following steps: acquiring aircraft track data and ground monitoring point coordinates and noise data, and converting the data into a three-dimensional rectangular coordinate system; screening effective noise events based on the noise data, and performing association matching with the track data; based on the Morse theory of a motion sound source, constructing an ellipsoid model representing the sound level contour surface of the aircraft noise; based on noise attenuation characteristics and an ellipsoid model, combining Doppler effect and atmospheric absorption attenuation, and constructing a nonlinear function of noise sound level attenuation along with distance; and carrying out parameter optimization solution by utilizing a genetic algorithm to obtain optimal parameters of the model and outputting a noise prediction result. According to the method, an existing noise prediction technology system is perfected, and the aircraft noise influence in the peripheral area of the airport can be accurately evaluated.

This invention relates to the field of low-altitude airspace management technology, specifically to a method, system, and storage medium for generating noise maps and optimizing flight paths for low-altitude aircraft. The method includes: extracting deep environmental features through an environmental feature encoding network; calculating a real-time noise map centered on the aircraft's current position using a physical-data hybrid noise prediction network, combining a physical acoustic model with neural network correction terms; generating a sequence of optimized flight actions for the future time domain based on the current noise map, aircraft state, and target point using a silent path optimization network; executing the first action in the action sequence, updating the aircraft state, and returning to perform rolling optimization for the next moment until the target point is reached. This invention, through the deep integration of a physical model and a data-driven model, ensures the correctness of acoustic principles while utilizing neural networks to compensate for complex environmental factors, achieving high-precision, real-time noise distribution prediction.