PBF-based fluid solidification simulation method and system

Abstract

The invention discloses a fluid solidification simulation method based on PBF, comprising: S1, initialization data; 2, searching that neighborhood of a fixed radius of the particle; S3, updating the solidification state of the particles; S4, applying the velocity decay factor to the particles, and the intermediate quantity of the position of the particles is calculated; 5, calculating that particle density and the motion constraint quantity; S6, calculating the position change amount of the particles and performing penetration prevention correction; 7, updating that velocity and position of the particles, and deal with the problem of collision between the particles and the boundary; S8, calculating the artificial viscosity and eddy current constraints. The invention also discloses a fluidsolidification simulation system based on PBF. The invention can simulate the speed of different fluid simulations through different particle velocity attenuation factors, and can also correct the particle penetration phenomenon through the position change amount, so as to realize larger scale and more efficient fluid solidification simulation under the support of GPU.

Description

technical field [0001] The invention relates to the technical field of fluid simulation, in particular to a PBF-based fluid solidification simulation method and a PBF-based fluid solidification simulation system. Background technique [0002] Fluids are ubiquitous in the real world, such as water, honey, blood, paint or paste, etc. In the VR virtual reality scene where fluid appears, drawing a fluid image that conforms to the laws of physical motion is one of the main links to make VR content feel realistic. The physical equations describing the motion of viscous incompressible fluids were inductively derived by two scientists, Claude-Louis Navier and George Gabriel Stokes, respectively, and named after them - the Navier-Stokses equation (hereinafter referred to as the NS equation). In the Cartesian coordinate system, the NS equation has the following form: [0003] [0004] [0005] Among them, D(·) / Dt represents the material derivative, ρ represents the density of ...

AI Technical Summary

Problems solved by technology

However, the simulation of fluid solidification cannot be realized only by relying on the PBF method. The PBF method mainly applies the PBD framework to the SPH method. A method for numerically solving approximate solutions to NS equations; NS equations describe the density maintenance and momentum conservation of viscous incompressible fluids during motion, and what is solved is the fluid motion caused by the joint action of internal and external forces. However, when the fluid solidifies, the interaction between the fluid molecules changes, and the gas phase state of the fluid changes. At this time, the NS equation is no longer suitable for describing the solidified fluid, so only the PBF method cannot be used for fluid solidification. the simulated

In addition, the fluid particles simulated by the PBF method are easy to penetrate the solid particles as the boundary; the method of the PBF method to realize the incompressibility of the fluid is to construct a position-dependent motion constraint function of the fluid particles based on the density of the fluid particles. The motion constraint function is zero to calculate the position change of the fluid particles, so that the density of the fluid particles is basically equal to the static density, so as to realize the incompressibility of the fluid; whether the position change of the fluid particles can be accurately calculated is related to the number of neighboring particles, Therefore, the calculation of the position change of the fluid particles at the intersection of the fluid and the solid boundary may have a large error; and the error may become larger under the action of an external force, and finally the fluid particles penetrate the solid particles at the boundary; therefore, after the fluid solidifies , it is necessary to consider how to prevent the flowing particles from penetrating into the solidified solid

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