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Cavitation flow structure frequency distribution characteristic analysis method

A technology of frequency distribution and flow structure, applied in fluid dynamics test, machine/structural component test, instrument, etc., to achieve the effect of clear physical meaning

Active Publication Date: 2022-07-29
CHINA SHIP SCIENTIFIC RESEARCH CENTER (THE 702 INSTITUTE OF CHINA SHIPBUILDING INDUSTRY CORPORATION)
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  • Description
  • Claims
  • Application Information

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Problems solved by technology

At present, there is no effective technical means to solve the above technical problems

Method used

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  • Cavitation flow structure frequency distribution characteristic analysis method
  • Cavitation flow structure frequency distribution characteristic analysis method
  • Cavitation flow structure frequency distribution characteristic analysis method

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Embodiment Construction

[0028] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0029] The current research on cavitation flow structure mainly relies on visual observation, that is, a series of images of cavitation morphology are obtained by means of stroboscopes or high-speed cameras, such as figure 2 shown, followed by a qualitative description of the observed cavitation structure, which lacks quantitative characterization of the flow structure characteristics.

[0030] Aiming at the problem that cavitation flow structure feature description is mainly subjective description, the present invention proposes a cavitation flow structure frequency distribution feature analysis method combined with data processing and characterization methods, such as figure 1 As shown, the method includes the following steps:

[0031] Step 1: Construct an image grayscale matrix based on the cavitation morphological image, including:

[0...

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Abstract

The invention discloses a cavitation flow structure frequency distribution characteristic analysis method, and relates to the field of cavitation structure analysis, and the method comprises the steps: taking a high-speed photography image sequence as input, and constructing and forming a gray matrix arranged according to a time sequence; extracting gray values arranged according to time at the position of a single pixel point in the gray matrix, performing FFT (Fast Fourier Transform) on the gray values, and storing a result to the same pixel position in the matrix with the same image resolution; all pixel points are processed to obtain a frequency matrix which is consistent with an input image in spatial resolution and has a frequency characteristic in the other dimension. And then, by extracting data of the same frequency dimension, the distribution of a certain frequency characteristic of the cavitation structure in the space is obtained, and the result can be flexibly represented through a contour line, a cloud picture and the like. The method is suitable for analyzing the cavitation unsteady flow structure characteristics of the standing streaming object, and can provide support for analyzing the frequency characteristics of a pulsation source caused by the cavitation flow structure.

Description

technical field [0001] The invention relates to the field of cavitation structure analysis, in particular to a method for analyzing frequency distribution characteristics of cavitation flow structures. Background technique [0002] The occurrence of cavitation usually causes vibration, noise and cavitation in engineering. The reason is that the evolution of its unsteady flow structure will lead to strong pulsation in the flow field. In the past, its understanding and description were mainly based on qualitative means such as observation and description. Mainly, there is a lack of quantitative technical means. In particular, there is very limited understanding of what kind of flow structure of cavitation produces the characteristic frequency characteristics in the cavitation flow field. Therefore, how to extract quantitative information based on the traditional image observation method is an important link in the research on the characteristics of cavitation pulsation source...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01M10/00
CPCG01M10/00Y02T90/00
Inventor 曹彦涛祁江涛翟树成许影博
Owner CHINA SHIP SCIENTIFIC RESEARCH CENTER (THE 702 INSTITUTE OF CHINA SHIPBUILDING INDUSTRY CORPORATION)