Velocity field quick correction method and device based on hydrodynamics continuity equation

A technology of fluid mechanics and velocity field, which is applied in fluid velocity measurement, velocity/acceleration/impact measurement, measuring devices, etc. It can solve the problems that the minimum correction of the velocity field cannot be guaranteed, the computer hardware requirements are high, and the velocity field is over-corrected. Achieve the effects of facilitating parallel computing, improving computing efficiency, and eliminating residual errors

Active Publication Date: 2016-09-07
BEIHANG UNIV
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the current method for solving this optimization problem consumes memory, is inefficient, lacks practicability, and requires high computer hardware, so it is difficult to be used for actual velocity field correction
Other non-optimized correction methods cannot guarantee the minimum correction of the original velocity field, so it may cause excessive correction of the velocity field, thereby introducing additional errors

Method used

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  • Velocity field quick correction method and device based on hydrodynamics continuity equation
  • Velocity field quick correction method and device based on hydrodynamics continuity equation
  • Velocity field quick correction method and device based on hydrodynamics continuity equation

Examples

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Effect test

Embodiment 1

[0027] A method for fast correction of the velocity field based on the fluid mechanics continuity equation of the present invention, the process is as follows figure 1 As shown, the specific implementation steps are as follows:

[0028] Step 101: Determine the discrete form of the continuity equation;

[0029] The TPIV measurement result of incompressible flow is the 3D3C instantaneous velocity field distributed on the nx×ny×nz regular structure grid nodes, and Δx, Δy, Δz are the grid spacing in the three directions of x, y, and z. Let u, v, w be three velocity components, and the form of fluid dynamics continuity equation is This equation involves the partial derivatives of the velocity field along three coordinate directions. In order to facilitate subsequent calculations, the discrete form of the continuous equation is given first. Assume that the value of u on the grid node (i, j, k) is u ijk , The corresponding value is The central difference scheme is used for t...

Embodiment 2

[0062] The method of the present invention will be described below in combination with specific application scenarios.

[0063] The following implementation of the velocity field correction is for figure 2 a shows the instantaneous velocity field with Gaussian noise applied. Tests can also be performed with different artificial noise sources.

[0064] Gaussian random noise is applied to a 100×100×16 velocity field in Direct Numerical Simulation (DNS). Δx=Δy=Δz=1. The mean μ of Gaussian random noise is 0, and the variance σ is 0.1 times of the velocity variance. The probability density function f(x) of Gaussian random noise is

[0065] f ( x ) = 1 2 π σ exp ( - ( x - ...

Embodiment 3

[0082] The embodiment of the present invention also provides a rapid correction device for the velocity field based on the continuity equation of fluid mechanics, such as image 3 As shown, the device can be located inside the computer, including a continuous equation discrete form module 301 , a velocity field divergence calculation module 302 , a discrete derivative operator decomposition module 303 , and a velocity field reconstruction module 304 .

[0083] The discrete form module 301 of the continuous equation obtains the discrete form of the continuous equation by analyzing the grid coordinates of the velocity field, expresses the divergence operator through a one-dimensional derivation operator, and at least obtains the form of a one-dimensional derivation operator matrix.

[0084] The velocity field divergence calculation module 302 calculates the residual error of the original velocity field divergence through the discrete form of the continuity equation, and the resid...

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Abstract

The invention discloses a velocity field quick correction method and device based on a hydrodynamics continuity equation, and the device comprises a continuity equation discrete form module, a velocity field divergence calculation module, a derivation operator decomposition module, and a velocity field reconstruction module. The method achieves the direct calculation of a corrected velocity field through the eigenvalue decomposition of a one-dimensional derivation operator, and the obtained velocity field meets the continuity equation completely in a discrete form. The method achieves the most conservative correction of an original velocity field. The method and device can greatly improve the calculation efficiency, and reduce the consumption of a memory. The method is enabled to be higher in applicability.

Description

technical field [0001] The invention relates to a rapid correction method and device for a velocity field based on fluid mechanics continuity equations, and belongs to the technical field of fluid mechanics velocity measurement. Background technique [0002] Particle Image Velocimetry (PIV) is one of the most important quantitative measurement methods in the field of experimental fluid mechanics. This technology obtains the velocity field in the measurement area by analyzing the imaging of the tracer particles on the camera. With the development of measurement technologies such as Tomographic Particle Image Velocimetry (TPIV), it is more and more convenient to obtain all three velocity components (Three-dimensional Three-component, 3D3C) in the three-dimensional space. The 3D3C velocity field contains all velocity gradient components, allowing the use of the basic equations of fluid mechanics to test the measurement accuracy of the velocity field. For incompressible fluids...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01P5/00
CPCG01P5/00
Inventor 高琪王成跃王晋军
Owner BEIHANG UNIV
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