High-order gradient smooth meshless method and system, medium and computer equipment

Abstract

The invention belongs to the technical field of structural acoustic radiation prediction, and discloses a high-order gradient smooth meshless processing method and system, a medium and computer equipment, and the method comprises the steps: constructing a mathematic model for calculating the weak meshless coupling DtN boundary of free field structural acoustic radiation through a Galerkin weighting parameter method; softening the rigidity of the numerical model through a high-order gradient smoothing algorithm and reducing a numerical dispersion error by adopting local gradient smoothing under a weak meshless framework; reducing numerical interpolation errors by optimizing a meshless interpolation scheme; verifying the accuracy, stability and practicability of the method through numerical values and tests. According to the method, the weak meshless method coupled with a DtN boundary is analyzed, a numerical method capable of accurately calculating free field structure acoustic radiation is constructed, theoretical and algorithm bases are provided for accurate forecasting of low-frequency noise in a ship structure, the accuracy of low-frequency noise forecasting in the structure is comprehensively improved, and theoretical and technical bases are laid for noise control over ships and warships.

Description

technical field [0001] The invention belongs to the technical field of structural acoustic radiation forecasting, and in particular relates to a high-order gradient smoothing gridless processing method, system, medium and computer equipment. Background technique [0002] At present, acoustic stealth performance is one of the important comprehensive performances of ships. The noise radiated from ships directly determines the detection probability and detection distance of our ships by enemy underwater acoustic detection equipment, and also affects the detection range of the ship's own sonar. High, seriously reducing the combat performance of ships. With the continuous improvement of the performance of underwater acoustic detection equipment, the world's major naval powers have made low noise levels one of the key goals for the design and manufacture of new-generation ships. In the field of civil shipbuilding industry, noise control is a difficult problem in the design and man...

AI Technical Summary

Problems solved by technology

[0007]The problem of numerical dispersion error in the mid-frequency band has always been a difficult point and hot spot in the field of acoustic vibration and solid mechanics, and the existing low-frequency and high-frequency solution methods cannot be solved independently this kind of problem

It is this weighted average approximation that makes the model stiffness "too soft", leading to spurious non-zero energy modes when solving for vibration analysis

For the calculation of free-field structure-acoustic radiation, since the problem domain is an infinite domain, this particularity increases the difficulty of suppressing the numerical dispersion error in the mid-frequency range

[0011] In summary, when the traditional grid-based method calculates the mid-low frequency noise radiated by structures, the interpolation error that dominates the low-frequency band can be solved by refining the grid Grid to control, but the error reduction is limited, and the existing methods can not accurately calculate the intermediate frequency noise

For free-field structure-acoustic radiation problems, the infinite problem domain and the radiation conditions that need to be satisfied at infinity increase the difficulty of accurately predicting low-frequency noise

[0012]Through the above analysis, the existing problems and defects of the prior art are: the prior art cannot accurately calculate the intermediate frequency noise

For free-field structure-acoustic radiation problems, the infinite problem domain and the radiation conditions that need to be satisfied at infinity increase the difficulty of accurately predicting low-frequency noise

[0013]The difficulty in solving the above problems and defects is: at present, the value of the DtN spatial scale and the number of series items can only be roughly determined according to the empirical formula, while the existing The method of gradient smoothing algorithm softens the stiffness of the model too much. How to determine the appropriate value of the DtN boundary parameter and moderately soften the stiffness of the acoustic model is still unclear.

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