Hybrid Method Investigation In Fluid Simulation

With the rapid development of film, games and virtual reality industry, these industries have more demand for new technologies and new effects. Good effects can bring people more vivid feels.In these areas, physics-based simulation in special effects creation gradually become the mainstream. On the one hand, people have higher-level pursuit for the quality of special effects, the physical model can better respond to physical laws and present a more natural activities;On the other hand, the early special effects creation costs largely. For example, the establishment of a castle model, we often build it by scaling a real model and then use a series of measures to produce more realistic effects And inefficiency. Fluid simulation, as one of the film elements, play an increasingly important role. For example, in films "Shrek", "Lord of the Rings", "Water World" and so on, people was shocked by fluid simulation. At the same time, the game industry is also increasingly concerned about the impact of effects on the game.As to the complication of computation in fluid simulation modeling and simulation and the menthods are enormous, this paper raises a new coupled computational model to simulate two kinds of fluid interaction based on summarizing and generalizing the predecessors methods. In this paper, good and bad of the Euler method and Lagrange method are analyzed respectively. In detail, the movement of heated fluid is analyzed, the whole movement is divided into two parts:the first part is the velocity generated by the temperature diffusion of temperature field itself and convection, the second part is the pressure, buoyancy, viscous force, surface tension of fluid itself. In view of the respective characteristics of these two parts, the fluid simulation is computed using the stable flow method and SPH method respectively. Then a mathematical model is established and the two methods are coupled. At the same time this coupling method can correcting N-S equation, in order to make fluid looks natural. and then surface reconstruction is completed by using Maching cubes algorithm. At last, the iso-surface is rendered,with lighting model the lighting computations are achieved, the realistic effect is realized ultimately, the time efficiency is better than Level Set method.This first chapter outlines the history of the development of fluid simulation and previous research results. The second chapter describes the theoretical basis for fluid simulation based on the physical model. The third chapter analyzes the fluid heated movement theoretically and coupled Euler methed with Lagrange method after selecting the physical model. The fouth chapter realizes the simulation process and corrects physical model in heat diffusion and achieves experimental results. The fifth chapter analyzes the experiment again and give the expectations for theory development.