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Particle pair establishment method for SPH theory-based helicopter water landing load calculation

A construction method and load calculation technology, applied in computing, electrical digital data processing, design optimization/simulation, etc., can solve the problem of reconstructing particle equivalence, and achieve the effect of small workload and accurate calculation

Active Publication Date: 2018-05-29
CHINA HELICOPTER RES & DEV INST
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Problems solved by technology

In this way, the complex order of the problem is reduced from O(N2) to O(N), but there is still the problem that the particle pair must be rebuilt every moment

Method used

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  • Particle pair establishment method for SPH theory-based helicopter water landing load calculation
  • Particle pair establishment method for SPH theory-based helicopter water landing load calculation
  • Particle pair establishment method for SPH theory-based helicopter water landing load calculation

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Embodiment Construction

[0026] In order to make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be described in more detail below in conjunction with the drawings in the embodiments of the present invention.

[0027] When the present invention establishes the background grid in the water area, the length taken is kl+Δ, so the size of Δ determines the size of the grid unit space and the frequency of rebuilding particle pairs. If Δ = 0 then the standard linked list method is used to find the nearest particle, and the constructed particle pair must be reconstructed at each time step. If Δ is selected too large, the number of particle pairs constructed will be very large and wrong particle pairs may be introduced, resulting in increased computer memory usage and calculation time, and reduced calculation accuracy. The selection of Δ determines the quality of the actuarial results, and the purpose ...

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Abstract

The invention relates to a particle pair establishment method for SPH theory-based helicopter water landing load calculation. The method comprises the steps of 1, establishing a water domain background mesh, wherein the length of the mesh is k1+delta; 2, setting an upper limit value of delta for preventing introduction of wrong particle pairs; and 3, according to a physical law of water flow, setting a lower limit value of delta. According to the particle pair establishment method for the SPH theory-based helicopter water landing load calculation, the purpose can be achieved only by adding simple judgment statements in a calculation process, so that the workload is very small and the calculation is accurate.

Description

technical field [0001] The invention belongs to the field of helicopter flight dynamics and flight load calculation, in particular to a particle pair construction method based on SPH theory for helicopter landing load calculation. Background technique [0002] The helicopter ditching load calculation method based on smoothed particle hydrodynamics (SPH) theory can calculate the overload, skin surface pressure, attitude, etc. of a three-dimensional full-scale helicopter under different working conditions. The basis of the SPH method is the integral interpolation theory, which discretizes the calculated water flow field into a series of particles, and the particles have velocity, internal energy and quality parameters. The parameters at any position in the flow field can be obtained by integrating the "kernel function" with the parameters of the surrounding particles. Finally, the basic equations of fluid mechanics are converted into equations for SPH numerical calculation, a...

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Application Information

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IPC IPC(8): G06F17/50
CPCG06F30/15G06F30/20
Inventor 索谦汪正中陈立霞马玉杰陈金鹤鲁可刘长文武尚景陆召严
Owner CHINA HELICOPTER RES & DEV INST
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