Dynamic Simulation Of Changes Between Solid-Liquid-Gas Phases Based On Particle Mixture Model

Physics-based natural scene simulation and rendering is an important research direction in computer graphics.It has been widely used in film and television special effects,realistic games,natural landscape simulation and other fields,and has attracted more and more attention in recent years.One branch of this field is to simulate specific scenarios by building computational models.In the simulation of a simple scene containing a single phase,the classical model in the field of mechanics can be directly adopted.However,for complex scenarios involving multiple phases,it is necessary to extend the base of the basic computational model.In this paper,the transition between solid,liquid and gas phases of a single substance is taken as the target,and the corresponding computational model is constructed based on the particle computing framework.In order to simulate the scene containing multiple phases,the original complete particles were divided into multiple components,and the mass fraction vector was used to represent the spatial distribution of the masses of each phase.Then,the temperature field is superimposed in the simulated space,and a phase transition model is constructed to calculate the transformation of the mass fraction vector in the composite particle.At the same time,in order to simulate the phenomenon of "phase change delay" in reality,the accumulation process of "latent heat of phase change" is added to ensure that the phase change can only occur when both critical temperature and latent heat are satisfied.In order to calculate the spatial position migration of the composite particles,a motion model suitable for composite particles is constructed.Based on the similarity between the two classical physical models in fluid mechanics and solid mechanics,a unified computational model can be built for composite particles by integrating relevant mechanical terms.After obtaining the spatial position of particle sets,the Level Set algorithm was used to construct the spatial distance field,and the Marching Cube algorithm was further used to extract the collection of triangular faces from the spatial distance field,and finally the results after rendering were obtained through pov-ray Ray Ray tracker.The above particle mixture model is used to simulate three scenes: the "melting" scene of solid-liquid transition,the "boiling" scene of liquid-gas transition and the composite scene containing three phases.The results show that the model can be used to simulate the phase transition.At the same time,the computational time of the particle mixture model is comparable with the latest methods in the simulation of each scene.